Llansadwrn (Anglesey) Weather Diary 2004

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Times are GMT (UTC, Z). Observations at this station [ ] are 24-h 09-09 GMT, some others { } occasionally refer to 24-h 18-18 GMT, and are subject to verification and amendment.

January 2004

1st: Frontal rain, that had accumulated 17.0 mm overnight, was clearing away to the SE after 0030 GMT leaving broken cloud with showers that included falls of ice pellets. The new year dawned damp and grey with low cloud and only moderate visibility. There was standing water on some fields. Too warm for snow to fall even on the mountains where some wet patchy snow was seen lying near the cloudbase at 2100 feet on the Snowdonia Mountains. But overnight further N it was colder and there was up to 10 cm snow near Durham and deep snow in Scotland led to the closure of some roads. Some celebrations of Hogmanay were curtailed. The force 4 wind had veered NW'ly and pressure 1006 mb had just started to rise. An elongated low pressure system, lying Faeroes (986 mb) to N Scotland extending southwards, was being squeezed between high Scandinavian (1033 mb) and Atlantic (1035 mb) to the SW. A slight shower of rain then a little brightness for a time around noon and early afternoon but soon overcast again. During the night the sky partially cleared enough to give a ground frost. [Rain trace; Max 7.4C; Min 2.1C; Grass 0.5C]
2nd: A bright start to the day with only 3 oktas cloud cover. With a light SE'ly wind humidity had been as low as 67% at 01 GMT rising to 86% by 09 GMT. Pressure was 1020 mb with old low pressure and frontal cloud to the E. Pressure was high (1033 mb) both over Scandinavia and Azores. Snow on the mountains was very patchy and sparse with no continuous cover remaining except around the summit of Yr Wyddfa. The morning was sunny with the afternoon having variable amounts of cloud. Towards sunset frontal cloud was seen encroaching from the W and there was light rain at 23 GMT preceded by ice precipitation (small snow grains) that tinkled as blown against windows. The rain eased by 0330 GMT when there was some clear sky and a ground frost. [Rain 3.1 mm; Max 6.6C; Min 1.6C; Grass -1.1C]
3rd: Overcast at dawn and although there was a hole in the cover overhead at 09 GMT that was the only sky seen during the day. Pressure was little changed at 1019 mb. Cloud thickened and lowered during the morning and it became misty. The day was sunless and damp with little wind (Piche evaporation only 0.1 ml). There was drizzle, sometimes heavy with a spell of light rain around 1430 GMT. [Rain 0.4 mm; Max 6.3C; Min 1.8C; Grass -1.8C]
4th: Overcast overnight the sky started to clear at dawn leaving much high cirrus cloud at 09 GMT. There was cirrostratus to the W and low dispersing cloud to the NE. There has been no sight of the "shed" robin for the last 2 mornings. The morning was sunny with further clearance of cloud. During the afternoon it became cloudier from the W but kept dry until just before 2100 GMT. There was a log spell of drizzle, heavy at times, through the night that accumulated 1.1 mm (5.6h duration). [Rain 1.1 mm; Max 9.3C; Min 3.9C; Grass 0.2C]
5th: At midnight low A (990 mb), of Canadian origin, was over Belle Isle Strait, Newfoundland and on-track towards the UK. Here in moist warm sector air of another system the temperature had been rising in the past 24-h. At 09 GMT it was 9.3C and 100% humidity in low cloud and slight drizzle. Pressure was 1013 mb with low pressure (997 mb) just W of Ireland. For the 3rd morning the robin has not appeared for it's crumbs at the shed door. It must have died from old age, or taken by sparrowhawk that has been around for the last week, it has been regular for some years. The deepening low A was (982 mb) at 06 GMT off St. John's, Newfoundland while there was high pressure (1020 mb) Scandinavia and (1027 mb) S France and N Africa. The morning was dull and misty with the low cloud persisting and fronts associated with the low W of Ireland brought drizzle intermittent with light rain from 1500 GMT to 2300 GMT when, on a weak cold front, rain turned heavy until about 0200 GMT before dying out at 0300 GMT. By 1800 GMT the low A was (969 mb). {Hawarden, Flintshire 12.1C}. [Rain 15.7 mm; Max 10.1C; Min 4.0C; Grass 0.5C]
6th: Before dawn the sky was almost clear with bright stars and setting full moon low to the NW. The temperature was falling and reached 6.1C, the minimum, at 09 GMT. With the warm temperatures no snow had fallen over the mountains but there were still patches mainly in gullies above 2000 feet. With low (990 mb) now near Cape Wrath pressure 1010 mb was rising as a ridge of high pressure was about to cross from the W. After some patchy cloud dispersed the morning was sunny with a light W'ly wind. Windier in the afternoon (backing S'ly) but still mostly sunny. Low A was (958 mb) SE of Greenland at 18 GMT. The evening was mostly clear and very mild (temperature around 10C) but became cloudier during the night with a little drizzle around 05 GMT. [Rain 0.1 mm; Max 10.1C; Min 6.1C; Grass 4.0C]
7th: A bright but windy start to the day. Pressure 1006 mb was falling with low A (959 mb) S of Iceland dominating the weather. The S'ly wind was a gusty force 6 with the temperature on 10.1C (dewpoint 6.0 RH 76%) and went on to reach 11.0C, the warmest day of the month. A new robin has taken over the shed territory. It has bright and smart feathers so could be a young bird, possibly 'son of shed robin'. The first snowdrops are in flower. The morning kept bright but there were some cumulus clouds in the vicinity and later orographic waves developed. A little sunshine in lee-clearance in the afternoon. The evening and night was mostly clear until frontal cloud moved across. [Rain 4.2 mm; Max 11.0C; Min 4.2C; Grass 0.5C]
8th: Pressure 994 mb at midnight began to fall quickly and was 975 mb at 0900 GMT. Complex low (958 - 960 mb) was S of Iceland we were near the middle of a developing peripheral low within it's circulation, with associated front, over St. George's Channel. The wind was light SE'ly force 2, but within minutes had veered SW'ly force 6/7. There was light rain since 0630 GMT and visibility in low cloud was poor. The large area of rain crossing the UK had some heavy rain within it particularly on high ground in Wales, the SW and Scotland. Continuing mild with the temperature hardly varying from 10C. The overnight minimum of 9.0C was the warmest of the month. A wet morning (3 mm) and during strong gusts of gale force wind an ash tree, on the roadside nearby, was blown down but into the adjoining field where it did little damage. Later the wind eased a bit and there was a little sunshine as the sky partially cleared. On the high tide at 1145 GMT there was a surge (Gladstone Lock, Liverpool, POL tidal gauge 0.5 m) that tested the sea defences of islands in the Menai Strait. (The next high tide in the night passed without a surge). Dry with some sunshine in the afternoon and partial cloud in the evening and night. [Rain 4.0 mm; Max 10.3C; Min 9.0C; Grass 7.8C]
9th: Showery towards dawn with an active trough in the W. Sferics were reported SW Ireland, SW England and Wales. At 09 GMT fresh snow had fallen on the mountains. It was lying generally at 2000 ft and as low as 1200 ft in Cwm Idwal and the Llanberis Pass. A shower of about 1 mm was just clearing away and it was bright to the W. Pressure 997 mb was rising with low (969 mb) moved N to the Faeroes joining the circulation S of Iceland. Pressure was high (1030 mb) over Gibraltar Strait and there is no Scandinavian high at the moment having been moved far to the E. There is a developing Atlantic-low (993 mb) to the SW. The temperature was just recovering from the minimum of 4.8C. The new 'shed robin' was waiting for me to arrive this morning, so he had his crumbs. He is not as tame as the previous, that used on occasions to come into the shed to help himself. The day was bright at times, with cumulus clouds in the vicinity, any precipitation being confined to the mountains. Towards sunset clouds diminished and it was less windy. Minimum temperatures (air 4.0C; ground -0.3C) occurred between 19 - 20 GMT. Thereafter temperatures rose as warm frontal cloud on low (986 mb) near the Western Isles approached. [Rain 1.0 mm; Max 9.3C; Min 4.8C; Grass 2.8C]
10th: Showery rain after midnight with the temperature continuing to rise. At 09 GMT it was 9.3C and the maximum of the past 24-h. Pressure 1005 mb was rising a little with low pressure moving N, but there was more of the same in the Atlantic to follow. The morning was dull. It was misty over the western slopes of the mountains where, following the temperature rise, any snow was confined to gully patches where it had been deeper. The wind strengthened during the morning and with descending cloud there was mist and drizzle in the afternoon. There was a spell of rain on a warm front from 2300 - 0200 GMT with the 24-h maximum temperature of 10.7C at 01 GMT. [Rain 5.2 mm; Max 10.7C; Min 4.0C; Grass -0.3C]
11th: From 0330 GMT the temperature was falling as a cold front approached. There was a moderate shower of rain and small ice pellets about 0400 GMT with the minimum temperature about 0800 GMT. At 0900 GMT with pressure on 994 mb it was still overcast. But by 0930 GMT the sky was beginning to clear as we entered an unstable strong W'ly airstream. There were well developed cumulus clouds particularly over Snowdonia with strong radar echoes and sferics reported to the W and over Ireland. A waterspout was reported seen during a thunderstorm in the Bristol Channel about 1310 GMT. The sky was described as being very dark above the spout estimated as being 2000 ft high. It moved for about 20 minutes up the Channel and inland being then classed as a tornado. No damage was reported. The morning here was bright but the f5 WSW'ly wind strengthened to force 6/7. The afternoon was cloudier with a slight shower of rain but the wind moderated by dusk. The evening and night were partially cloudy. [Rain trace; Max 6.5C; Min 5.5C; Grass 2.2C]
12th: Pressure continued to fall slowly reaching 991 mb at 09 GMT. An Atlantic wave-depression (988 mb) had reached Lands End and was expected to move up the English Channel generating strong winds through the day. Here it was a bright start to the day with little or no W'ly wind. The mountains were capped and largely obscured with a band of cloud, but over Anglesey there was much blue sky with cirrus and altocumulus clouds. The sky had been sufficiently clear for dew to form on the grass but the temperature stayed just above freezing (0.2C). The autographic raingauge needed attention so as it was a fine morning the job was put in hand. It had recently malfunctioned by not siphoning properly. The routine job took rather longer than expected. Usually a small piece of leaf debris gets stuck at the top of the siphon tube. I spotted something and usually it can be removed or washed out by pouring in clean water. This morning the obstruction was moving slightly, was tenacious and proved to be a live Forficula auricularia, an earwig. Somehow it had managed get to the top of the siphon tube possibly by climbing up the outflow tube inside the raingauge. Other possible entry points are few as the rainwater is filtered through a fine mesh and a necessary pin hole for air. Also it would have had to have been under water at some point. Equivalent human endeavours involving traversing sumps during pot holing in limestone caves come to mind. It was remarkably tenacious but I got it (live) out in the end (see photo). As the raingauge is heated, to avoid frost damage, it must have been providing a comfortable home for the winter, it usually has spiders and cluster flies. The morning turned cloudier by noon but the afternoon was mainly sunny with the cloud almost lifting off the Snowdonia Mountains. A sprinkling of ice precipitation was seen above 2700 ft on the Carneddau, Snowdon as usual remained obscured. After sunset cloud frontal encroached from the W as another low (974 mb) just W of Galway Bay, Ireland, was tracking further N. By 2200 GMT, the S'ly wind had reached gale force 8 with gusts over 50 mph, and pressure had fallen to rapidly to 981 mb setting off the Oregon storm alarm. There was a moderately heavy shower of rain before the wind moderated a little after midnight as the low tracked across the Irish Sea. (Aberporth reported a gust of 69 mph, Valley 57 mph). [Rain 4.6 mm; Max 8.6C; Min 3.9C; Grass 0.2C]
13th: Pressure was lowest 975 mb between 03 - 04 GMT then the wind veered W'ly and strengthened again touching gale force 8 with renewed strong gusts around 05 GMT. In Pembrokeshire 1500 homes had been left without electricity. By 0900 GMT with the low (970 mb) in the North Sea pressure here had risen to 982 mb with the wind force 5/6. Cloud was ragged and moderately low with mist on the lower slopes of the Snowdonia Mountains. The day brightened as cloud lifted and thinned but in the afternoon it became colder and there was some convective cloud development. At 1600 GMT there was a shower of rain and ice pellets. The night was mostly overcast. [Rain 0.6 mm; Max 7.5C; Min 4.0C; Grass 1.6C]
14th: Under grey moderately high uniform cloud the day began dull. Pressure was low 993 mb as a frontal cloud brought precipitation in from the SW. Just before 09 GMT there was light rain than fell as snow above 1500 ft on the mountains of Snowdonia where 2 cm was reported. In mid and south Wales several centimetres accumulated and 11 schools had to close. The A470 between Llanidloes and Llangurig became blocked while the A40 between Brecon and Llandovery was difficult. Later up to 8 cm of snow was reported near Crickhowell. Here there was only intermittent light rain or heavy drizzle at times. The snow was probably caused by an evaporative cooling effect, when there was little or no wind, near the centre of the low over South Wales at the time. With little mixing of the air taking place evaporation of precipitation would cause cooling enough to turn it to snow. Conditions were not right here. During the afternoon deep convective clouds moved across from Ireland and at 1515 GMT there was a moderate shower of ice pellets. The evening saw more ice pellets at 2120 GMT. {Aberporth, Ceredigion 17.5 mm; Sennybridge lowest day maximum of 1C}. [Rain 1.9 mm; Max 4.8C; Min 3.1C; Grass -0.5C]
15th: At 0430 it was a little warmer (max 4.8C) then there was some cloud clearance resulting in a touch of ground frost just before dawn. Before 09 GMT cloud approached from the W as slow-moving low (986 mb) W of Ireland approached the Irish Sea. Pressure here 1000 mb started to fall quickly and the SW'ly wind backed S and strengthened as rain started to fall by 1000 GMT. It was a wet day with rain becoming moderate to heavy by noon with areas of rain circulating the low. With rising temperature here there was no snow, but 13 cm was reported near Durham in the afternoon. By 16 GMT 17 mm rain had accumulated and further spells of rain in the night, continuing to circulating within the low pressure, brought the total to 24.6 mm by morning. {Capel Curig 40 mm}. Pressure was at its lowest 979 mb around midnight when the WSW'ly wind was touching gale force with gusts of 50 mph. [Rain 24.6 mm; Max 8.3C; Min 1.9C; Grass -0.8C]
16th: Overcast at dawn with low ragged clouds and moderate convection developing. Just before 09 GMT there was a shower of rain and ice pellets. Pressure 992 mb was rising with yesterday's low (975 mb) moved into the North Sea. The wind was light NW'ly. As the last of the frontal cloud moved E the morning brightened and there was sunshine by 1100 GMT but the mountains remained shrouded in cloud all day. A mainly sunny afternoon but convective clouds moved across and gave a shower of ice pellets about 1830 GMT. A mostly clear night and with moderate freezing on the ground the road gritters were out to salt the roads. [Rain 0.5 mm; Max 7.2C; Min 4.1C; Grass 2.6C]
17th: A bright morning with cloud over the mountains breaking up at 0900 GMT with wide crepuscular rays seen in the Nant Ffrancon Pass. Fresh snow was lying at 2250 ft but lower at 1650 ft at the head of the Pass. Pressure was 1002 mb with slack pressure gradient over the UK. Pressure was high (1024 mb) W of Iberia. The day was mostly sunny with a light NE'ly breeze. The evening and night was mostly clear with air temperature falling to 0.1C with a moderate ground frost -4.2C. {Rhyl 13 mm}. [Rain 0.0 mm; Max 5.3C; Min 1.3C; Grass -2.5C]
18th: Cloudier by dawn and there was a vivid 'sailors' warning' red sky. At 09 GMT the sky overhead had thin high cloud but there were clouds over Snowdonia and the approach of frontal cloud in the NW. Pressure was high 1026 mb in a ridge extending from the Azores (1032 mb) high. During the morning low cloud lifted off the mountains giving a clear view of the snow covered range. Cloud thickened from the NW during the afternoon as rain over Scotland edged S. By 1500 GMT it reached here and there was fine drizzle as visibility deteriorated but amounts were small. Temperatures rose during the 24-h with the maximum of 8.1C recorded just before 09 GMT the next morning. [Rain 0.9 mm; Max 8.1C; Min 0.1C; Grass -4.2C]
19th: A dull and misty start to the day with a spell of rain leading up to 09 GMT contributing most to the 0.9 mm for the past 24-h. Pressure 1019 mb had fallen between low pressure (994 mb) Iceland, low (993 mb) Sweden and high pressure (1033 mb) in FitzRoy near Cape Finisterre. Isobars were moderately tight here with the W'ly wind force force 4. The new robin within days is much tamer and comes into the shed for crumbs when I make the observations. He has taken over this position and chases off any intruders. The day kept misty in low cloud with only moderate visibility. In the Scottish Highlands it was a very wet day under a slow-moving front {60.7 mm} falling at Loch Glascarnoch. The night kept overcast with mist and fine drizzle at times. [Rain 3.0 mm; Max 9.8C; Min 1.0C; Grass -0.3C]
20th: Light rain from 0630 GMT continuous at 0900 GMT contributed mostly to the 3.0 mm recorded. Pressure was 1018 mb still in the ridge from slowly declining high (1029 mb) Iberia Peninsular. Atlantic low pressure systems were to the W while a low S Baltic had associated fronts bringing the rain down the spine of the UK, but snow to much of Europe especially Germany. High (1022 mb) of small area was over N Scandinavia. The day was wet and misty with a light W'ly breeze. The rain that turned moderate during the morning ceased at 1500 GMT but it remained overcast. [Rain 6.3 mm; Max 8.8C; Min 7.8C; Grass 7.4C]
21st: Overcast but no measurable rain through the night. It had been a very damp 24-h with zero evaporation and relative humidity at or near 100%. Little variation in temperature but becoming cooler with the minimum 6.0C at 0900 GMT. Pressure was 1021 mb with the persistent ridge over the UK. The Scandinavian high (1025 mb) had built a little and was extending S over Europe. Sometimes these highs can develop and block the westerly run of Atlantic-lows and, at this time of year, lead to some cold 'continental' weather somewhat lacking recently. The day was overcast, sunless and dull with little or no wind. There was little or no precipitation to be seen anywhere {Lerwick, Shetland 9 mm}. [Rain 0.6 mm; Max 8.5C; Min 6.0C; Grass 5.3C]
22nd: During the night the wind strengthened from the S and there was a little rain around 05 GMT. Little temperature range in the past 24-h from minimum 6.0C at 09 GMT yesterday to maximum 8.5C at 09 GMT today. Pressure 1009 mb was falling with complex low pressure and frontal systems moving in from the W. There was a large area of rain covering S Snowdonia, the Midlands and the South West. Here some early spots of rain dried up but the morning kept overcast. It was brighter in the lee of the mountains on the mainland in Llanfairfechan and Conwy. At Colwyn Bay the temperature rose to 14C and there were 3.6h sunshine, both highest in the UK. Here the afternoon did brighten up later and cloud cleared from the mountains. The air was very clear and fine views were seen in later afternoon sunshine. There were just some small patches of snow remaining mainly above 3000 ft. By evening further cloud encroached from the W. Milford Haven, Pembrokeshire, was wettest with {22.4 mm}. [Rain 0.2 mm; Max 10.1C; Min 6.0C; Grass 5.3C]
23rd: A vivid red sky above the mountains to foretell of approaching frontal rain stretching from SW Approaches up St George's Channel and Irish Sea to the Western Isles of Scotland. But it was still dry at 0900 GMT but it had become overcast. Pressure was 1010 mb with low (970 mb) SE Iceland. A weak area of low pressure was over France. The Scandinavian high (1027 mb) is sinking S towards the Adriatic while high (1026 mb) is off Iberia. It began to rain by 1145 GMT, light at first but was moderate at times in the afternoon, ceasing about 1900 GMT. The S'ly wind veered WNW by 2100 GMT by when the sky had almost cleared and there was a ground frost. [Rain 7.8 mm; Max 9.2C; Min C; Grass C]
24th: A sunny start to the day with altocumulus clouds dispersing overhead. Pressure was 1016 mb and we were in a cooler but showery W'ly airflow. There were some clouds mainly in the W and over the mountains but they kept away here and the day was dry. During the afternoon convection increased and some well developed clouds were seen to the W and over the mountains that were mostly obscured all day. As the sun set crepuscular rays were seen behind the then decaying cumulus clouds. The night was mostly clear with water deposits and additional dew freezing on the grass. [Rain trace (dew/fr); Max 8.7C; Min 2.7C; Grass -1.5C]
25th: The grass was white with frost lasting well into the morning in shady places. The sky had 6 oktars of mainly cirrus clouds at 09 GMT but these dispersed during the morning. Storm cocks (mistle thrushes) were singing strongly high in the trees establishing there territories, there are 2 or 3 pairs locally. They have been singing from dawn every day for the past week even in the rain. Great spotted woodpeckers were drumming close by and being answered by more distant birds. Pressure 1014 mb was little changed but high pressure (1022 mb) was building to the W and stretching N to Greenland (1030 mb). Pressure was also high (1025 mb) N Russia but low (986 mb) to the N of the UK. This could bring cold wintry weather down from the N over the next week. The morning was mainly sunny at first; by noon there were showers of sleet with the temperature on 3.0C. These fell as snow on high ground and at 1400 GMT, when clearing, a reasonable covering of snow was seen on Foel-fras, Carnedd Llewelyn and Yr Wyddfa. With the sky mostly clear at dusk with the grass minimum falling to -3.4C moisture on grass and paths was soon frozen. [Rain 1.2 mm; Max 4.6C; Min 1.1C; Grass -3.4C]
26th: A bright but misty start to the day with inversion in the Menai Strait. Overhead dispersing altocumulus with cirrostratus to the W and NE. At 09 GMT there was a light NE'ly with the temperature on 1.2C. Pressure was 1007 mb with slow-moving low (986 mb) and fronts and rain over Brittany. Cold polar air has reached Scotland with wintry showers in the N. The morning was bright with hazy sunshine. In the afternoon cumulus clouds built up over Liverpool Bay and in the W later where a cumulonimbus was spotted. Some clear spells at first at night with a shower of snow pellets close to 21 GMT.[Rain 0.2 mm; Max 4.3C; Min 1.0C; Grass -1.8C]
27th: Cloudier by dawn, with frost melted, but the cloud had lifted over Snowdonia revealing a light covering of snow generally at 2000 ft but as low as 1000 ft at Ogwen Cottage (Cwm Idwal). Pressure was 1013 mb with low (990 mb) Norwegian coast and high (1033 mb) Greenland with ridge to Wales. Complex low pressure was over France, Germany and the Mediterranean. It has been very cold with snow in Turkey; the Bosporus and Dardanelles were closed to shipping because of storms. The morning here was mostly cloudy with a N'ly breeze. Light snow showers, coming in off the Irish Sea, began to affect the NW corner of the island reaching here by 1112 GMT . Snow showers were also working their way down the E coast of England. But the morning brightened and the afternoon was sunny. Showers continued to move down through North Channel but kept to the W of the island. A cold front over Shetland between 11-12 GMT {6.4 mm} reached the Isle of Man at 1800 GMT. Although the temperature at 1900 GMT was near 0.0C, but when it reached here it had warmed over the Irish Sea and rose to 2.8C, so that precipitation fell as rain. But we did have a moderate fall of snow pellets, that almost covered the ground, in a blustery shower at 2300 GMT . Further E snow fell in Manchester and in SE England falls between 6-10 cm were reported. With maximums of 4.3C today and yesterday were the coldest of the month. {Tenby, Pembrokeshire 6.8h; Pembrey Sands, Carmarthenshire 9C} [Rain 2.7 mm; Max 4.3C; Min 0.9C; Grass -1.4C]
28th: No further showers after midnight and cloud was clearing after dawn giving a bright start. Too cold for the mistle thrushes to sing but the great spotted woodpecker was hard at it drumming on his favourite branch of mature pine. There was a scattering of snow pellets remaining on the grass; on the mountains snow cover was only sparse at 1500 ft. Pressure was 1008 mb with Greenland high (1025 mb) stretching to Cape Finisterre. To the E a line of low pressure centres stretched from N Norwegian Sea down the North Sea to Dover. A succession of fronts, another over Scotland at 06 GMT, and troughs were all moving S bringing the wintry weather. The morning here was bright with a moderate to fresh NW'ly wind. The front arrived about 1345 GMT. There was rain at first then, as the temperature fell rapidly from near 5.0C to -1.0C, a burst of snow pellets before turning to snow. The wind became a gusty force 6/7 blowing the snow almost horizontally for about 30 minutes. As the front moved on S it became active with thunder and lightning reported. The front reached the French coastline at 20 GMT. Several places including Yorkshire, the Midlands, the East Anglia and South saw most snow. Road and air travel was disrupted with some people unable to return home after the day's work. From 1600 GMT here the sky began to clear giving a cold night with a minimum -2.1C with -6.5C on the grass. [Rain 1.5 mm; Max 5.0C; Min -0.4C; Grass -4.5C]
29th: An almost clear sky and a sunny morning. Overnight temperatures air -2.1C and grass -6.5C were the lowest of the month. A little remnant snow was still lying on the grass, well below the 50% cover necessary to record 'lying snow'. There was only thin cover on the mountains, above an average of 1200 ft, and was sparser in places as low as 400 ft. Pressure was 1011 mb in a ridge lying to the SW from high (1021 mb) Spain. There were several centres of low pressure in the North Sea with frontal wave still giving snow to the N of Scotland.. It was a sunny day on Anglesey, with a light to moderate NW'ly breeze, but became cloudier by evening. [Rain 3.1 mm; Max 7.3C; Min -2.1C; Grass -6.5C]
30th: Overnight the air temperature minimum was 2.0C while there was a slight ground frost -1.2C after dusk before it became warmer. Introducing a change in the pattern low (957 mb), S of Greenland at 06 GMT, was bringing frontal cloud and warm sector air in from the SW. Ahead were fronts and troughs that brought intermittent rain from 04 GMT. Pressure was 1002 mb at 09 GMT and falling slowly but remains high over the Alps and North Africa. The temperature had risen to 5.5C and visibility was poor obscuring the mountains where snowmelt was rapid. The wind was a moderate SW'ly that strengthened to f6 through the day. By afternoon the rain turned moderate to heavy and continued all night, accumulating 27.6 mm by morning, the wettest day of the month. {Capel Curig 27.0 mm}.[Rain 27.6 mm; Max 10.1C; Min -1.4C; Grass -4.8C]
31st: It was still raining and in the low cloud and mist across the island visibility was very poor. Water was standing on the ground with a large pool in the middle of the 'old cricket field' opposite the weather station. Pressure had fallen to 980 mb as Atlantic low 971 mb (with frontal triple point) tracked across Galway Bay, Ireland. At 06 GMT there was a warm front over Wales, giving heavy rain over mountains and mid Wales, while the following cold front just reached Valentia, SW Ireland. Other slow-moving occluded fronts were over Scotland where it was still cold enough to give heavy snow, with 10-20 cm reported. Pressure went down to 997 mb in the afternoon as the low tracked across the Irish Sea. Strongest winds were in the SW with gale to storm force winds in the English Channel. The day here was wet with over 12 mm rain falling until 1800 GMT. {Capel Curig 74.2 mm} [Rain 17.8 mm; Max 10.4C; Min 5.4C; Grass 4.7C]

February 2004

1st: A minimum of 4.8C around midnight then warmer again as a further spell of rain from 01 - 0245 GMT produced another 5 mm. Then a clear slow around dawn but it was already cloudier at 0900 GMT. Pressure was 1005 mb with yesterday's low already over the Baltic. Low (979 mb) to the NW Scotland but another Atlantic-low (976 mb) is heading our way. The morning was dull with a strengthening f5 SW'ly wind. By 1300 GMT there were blustery showers of rain until 1800 GMT. As the low deepened (969 mb) and headed NE it brought a warm front in from the SW. There was moderate rain (3.0 mm/h) from 0300 GMT until just after 07 GMT. [Rain 20.3 mm; Max 10.5C; Min 4.8C; Grass 3.3C]
2nd: Dull grey uniform cloud and very poor visibility. It had stopped raining; the S'ly wind was force 6/7 but it did not stop the 'storm cock' singing about 0710 GMT. The ground was waterlogged and local roads were awash with runoff from adjoining fields. Pressure was 1008 mb with the Atlantic-low 965 mb heading towards NW Scotland. High (1032 mb) was building across North Africa, where a large dust storm in the Bodele Depression had crossed from Chad into Niger. Raised dust was blowing W into the Atlantic and could head N past the Iberian Peninsula towards Brittany and here. Here a dull, sunless, damp and windy mild day. At Colwyn Bay in the lee of the mountains there was 3.1h sunshine and the temperature reached 14C. There was rain from 1900 GMT and turned moderate to heavy from 2000 GMT continuing through the night. Traces of dust were observed (20 GMT), and intermittently during the rain, it's source was investigated and and most likely to have been of North African origin. The accumulated 33.4 mm rainfall was the wettest 24-h in the month. The SSW'ly wind reached gale force 8 during the evening with gusts of 50 mph. {Church Fenton 15C; Isle of Lusa 40 mm} [Rain 33.4 mm; Max 12.0C; Min 7.7C; Grass 5.2C]
¤ 3rd: At midnight low (962 mb) was S of Iceland with others in its wake. Overnight rainfall of 33.4 mm brought the total here for the past 4 days to 99 mm, 06 GMT on 30 January to 06 GMT today. Rainfall totals range from 46 mm in the Isle of Man to 204 mm in Capel Curig. Pressure was hardly changed at 1006 mb. The temperature at 09 GMT was a mild 11.4C and soon reached 12.5C, the warmest of the month. The SSW wind had again reached gale force, trees were being blown over in the area. A tall tree was left 'hung up' at 45° dangerously across the driveway to Gadlys. The sky was uniformly grey and visibility was poor. With river levels rising 32 warnings of floods were issued in Wales. At risk were the rivers Severn, Wye, Vyrnwy, Mawddach and Conwy. There was widespread disruption in North Wales. All roads into Llanrwst, Gwynedd, were flooded and 4 primary and the secondary school in the Conwy Valley closed. There was a tidal surge around the coasts, on top of the 8.0 m tide at 0930 GMT, that held back water in the Conwy and other estuaries. In 5 feet of rising water 3 men were rescued by RAF helicopter from a submerging car transporter at Llanrwst. Flooding at Trefriw took place when flood defences were breached trapping people in their homes. Gales continued during the morning, and had not moderated by afternoon, although there had not been heavy rain. Further rain was, however, forecast for later. In the afternoon 'Best Boy' John, with heavy farm equipment, made safe the tree suspended across the driveway. The night was mainly misty with a little drizzle but no heavy precipitation until morning. {Capel Curig 167 mm} [Rain 14.0 mm; Max 12.5C; Min 10.1C; Grass 9.5C]
4th: Rain from 06 GMT turned heavy from 07 GMT giving another 14 mm by 09 GMT. It had been another mild night, minimum 10.2C the warmest of the month, and the storm cocks were singing! Traces of a light reddish-brown coloured dust were being deposited on my 'clean' observing surfaces. The dust originated from the ongoing storms in North Africa, and were confirmed by backward trajectory analysis using the HYSPLIT model at NOAA ARL Website. The dust was probably picked up by parcels of air near the Atlantic-coast in southern Morocco between 00 and 06 GMT on the 2nd. It was transported in a westerly direction N of the Canary Islands at midnight on the 3rd then very rapidly NE past the Iberian Peninsula. It was W of Brest at 00 GMT on the 4th before moving up St. George's Channel to be deposited in Llansadwrn at 09 GMT. Although the level of the Conwy had fallen, some people Trefriw some people were still trapped in their houses. The A470 was closed between Llanrwst and Dolwyddelan as well as the B5106 at Trefriw. With more heavy rain and the high tide at 0945 GMT levels rose again during the day. There was a lot of water on the marsh at Malltraeth and the drainage channels were full. On the high tide water was higher than the gates protecting the fresh water pool. This filled with water and was within a whisker of flooding the road the landward side of the Cob. Pressure was 1011 mb with low (984 mb) to the SSW with complex frontal cloud, and triple point, slow-moving over the Irish Sea. The deluge continued with another 16.0 mm rain here by 15 GMT, but 86 mm fell at Capel Curig bringing the total there to 385 mm (15 inches). There was major disruption in Wales; 8 roads were closed in Gwynedd and 6 in Powys. There was flooding in the Tawe Valley and houses in Llandeilo were inundated. North Wales was cut off during the afternoon with all roads closed or difficult. The A55 was closed at Aber-Tai Meibon with traffic to and from Bangor at a standstill. The A5 was closed at Corwen, and was almost impassable at Betws-y-Coed. The A 4085 between Waunfawr and Rhydd Du was also closed. There was no further rain overnight. {Capel Curig 95 mm. [Rain 16.0 mm; Max 11.7C; Min 10.2C; Grass 9.5C]

The diagram above right shows rainfall accumulated at selected stations in North Wales and Isle of Man during the period 06 GMT on the 30th January to 06 GMT on the 5th February. It shows the huge amount (more than a foot) of rain received at Capel Curig compared with surrounding stations. Capel Curig received 393 mm (15.5 inches) over the period; the 116 mm (4.6 inches) in Llansadwrn was quite enough.

March 2004

1st: After a frosty night, with the grass minimum reading -5.9C the lowest of the month, there was hoar frost glistening in the early sunshine. Snow was still lying (55% locally at the weather station) and on the SE corner of the island (see TERRA satellite image). Much of the high ground in Wales remained snow covered. Pressure 1035 mb had risen as we were near the centre of the UK high. The temperature at 09 GMT was -0.3C (dewpoint -3.4C), and it was calm, while on Yr Wyddfa summit it was -6.8C rising. It was another sunny day with the temperature rising to 8.6C thawing more snow; on Yr Wyddfa the warmest I saw recorded by the AWS was -0.6C at 1500 GMT. The cold weather has slowed the previously advanced development garden daffodils, but some were out in the garden in time for St David's Day. Crocuses were covered in snow 4 days ago but have emerged undamaged. Haze (pollution smoke) increased through the day and could be seen to the west after a light purple-coloured sunset. Later high cloud moved in from the W. [Rain 0.0 mm; Max 8.6C; Min -1.8C; Grass -5.9C]
2nd: Overnight the minimum temperature was -2.0C, the lowest of the month. But it was a bright morning with red and purple sunrise at 0712 GMT. There was thin high broken cloud at 25000 ft and visibility was poor in smoke haze. Pressure 1033 mb was falling as the high (1037 mb) was drifting SE to Normandy and low (956 mb) SW of Iceland was making it's presence felt. Tightening isobars were to the W of Ireland and the wind here, S'ly force 3/4, was beginning to pick up. Although the day was overcast it kept dry and with a maximum of 7.1C remnants of snow continued to thaw. [Rain trace; Max 7.1C; Min -2.0C; Grass -5.5C]
3rd: The maturing Icelandic low (963 mb) was just W of Iceland at midnight. Overnight it was windier and there was no frost. It was a grey but dry dawn and the frontal rain over the Irish Sea did not reach here until 0835 GMT. Pressure was 1021 mb, the temperature 6.5C and the wind S'ly force 4/5. The showery light rain, would be falling as snow on the summits of Snowdonia where the temperature was still -1.8C, ended with a burst around 1030 GMT. Just remnant patches of snow here, but on the mountains, although now much sparser, was lying about 800 ft but there was a thaw later in the day. A dull day with a further spell of rain from 19 - 20 GMT leaving an overcast and mild night. [Rain 2.1 mm; Max 8.2C; Min 2.8C; Grass 2.3C]
4th: With all the snow melted the tape measure was put to another use; bluebell leaves were up to 15 cm long in the wood. It was brightening slowly at 09 GMT with the temperature on 7.4C. The mountain snow looked rather sad with only patchy cover above 2500 ft with some as low as 1000 ft. Pressure was 1018 mb with a cold front clearing slowly SE; there was complex low pressure in the Bay of Biscay with rain affecting the Channel Islands. The sky continued to clear during the morning and the afternoon turned sunny with a maximum of 12.6C. On the mountains, where temperatures went above freezing for the first time for several days, more snow melted. Later cumulus clouds developed to the E with several rain and hail showers over the Flintshire/Cheshire border as convection increased. Mr David Small reported that 'at Deeside we watched for about 5-10 minutes (about 1530 GMT) as a funnel cloud formed under the cloud base, probably about a couple of hundred feet in length. It seemed to be over the Shotwick Fields just west of the Deeside Industrial Park.' Soon after heavy hail showers were also reported over parts of Chester and on the A55 near Holywell. In the evening David Small also reported seeing, through patchy cirrus cloud, double halos around the moon. But the night here became misty with low cloud and fog by morning. [Trace/fog; Max 12.6C; Min 5.8C; Grass 4.9C]
5th: At dawn visibility was less than 100 m (code 1) but was starting to clear at 09 GMT. The temperature was 6.6C with 100% relative humidity and calm. Pressure had risen a touch to 1020 mb with high (1023 mb) W of Ireland approaching. By noon it was mostly sunny but low cloud and mist moved in from the sea in the afternoon. At 22 GMT almost full moon was just visible through the then fog (<100 m). [Rain trace/fog; Max 8.8C; Min 5.0C; Grass 1.5C]
6th: Just before dawn (0530 GMT) the fog began to clear and temperatures fell to their lowest giving a ground frost (-1.2C on the grass). By 0630 GMT shallow mist had formed on the fields but this cleared away just before 09 GMT. The sky at that point (3 oktas) there were cirrus and contrails overhead with cumulus were seen to the S and SW. Soon after 09 GMT cumulus clouds formed overhead and by 0930 GMT were well developed. A precipitating cumulonimbus was seen to the S heading for the mountains where, with temperatures just below freezing on the summits, there were showers of snow. Pressure was 1023 mb with high (1028 mb) close to SW Ireland. By noon there were some sunny spells but cumulus were still well-developed in the vicinity. In East Anglia and SE England convection was such that sferics were recorded in the afternoon. There was a slight shower of rain here at 1830 GMT. During the night the sky cleared and there was, with a bright full moon, a touch of ground frost. [Rain 0.2 mm; Max 10.7C; Min 2.2C; Grass -1.2C]
7th: A weak trough passed over about 06 GMT and had reached Birmingham by 09 GMT. Here the sky had almost cleared with some cumulus clouds to the S and W. Pressure was 1025 mb with high (1031 mb) near Valentia (Ireland). It was a mostly sunny day with a moderate (f4) N'ly breeze. It was cloudier around noon before the sky cleared in the afternoon. Cumulus clouds persisted over Snowdonia where there were snow showers on Snowdon and Carnedd Llewelyn. The evening was clear with dew but no frost by 2200 GMT although the road gritter had just passed. The night was clear with little or no wind. [Rain trace/dew; Max 9.0C; Min 3.0C; Grass -0.5C]
8th: Very heavy overnight dew had frozen white on the grass. This was soon melting in the morning sunshine. With the high (1039 mb) slow-moving over the UK pressure here was 1036 mb. Low (985 mb) S of Greenland had frontal cloud stretching down past W of Ireland. Stratiform cloud from over the North Sea affected most of S England with convective clouds developing later (see satellite image 1). Here there was a slight E'ly wind and although visibility was good it is was very hazy. The morning was sunny with a little stratocumulus, and cumulus clouds over the mountains. Just after noon it was cloudier (at most 4 oktas) just to the W of here as NE'ly air converged with SW'ly air (see satellite image 2) , but this cleared by 16 GMT. The W had the best of the sunshine with Valley reporting {9.0 h} but beaten by the Isle of Man {10.4 h}. Haze thickened through the day so that by dusk visibility was poor. Sunset was a pinkish-peach colour, as was the twilight, and the moon over the Carneddau at 21 GMT it was the same colour but when higher became whiter. These colours are because of fine particles, including dust, in the atmosphere at the moment. [Rain trace/fr; Max 10.2C; Min C; Grass C]
9th: A clear sky at night led to air (-0.8C) and ground frosts (-5.1C). Initial dew formation was much less than the previous night but there was deposition of hoar frost, directly from moisture in the air. This was covering plants, shrubs and rain gauges as well frozen dew on the grass. Hazy sunshine with a light NE'ly breeze and at 09 GMT a temperature of 2.5C soon melted the frost. Pressure 1036 mb was unchanged with the high (1042 mb) now over Scandinavia with a ridge to the UK. Deepened low (972 mb) was S of Greenland with associated fronts poised W of Ireland. The wind kept light NE/W'ly all day but cloud again developed in the afternoon as the wind became SW/W'ly on the west coast. Later the cloud dispersed and there was a colourful sunset and twilight and with clear sky at night turned frosty. [Rain 0.0 mm; Max 8.8C; Min -0.8C; Grass -5.1C]
10th: Clear before dawn the sky became rapidly cloudy from the E just before 09 GMT; you had to out early to catch the overnight frost as it had by then all melted. Pressure was 1032 mb under the influence of high (1044 mb) S Norway. Complex low-pressure S of Iceland with frontal cloud was still waiting W of Ireland. The morning, still hazy, was occasionally brighter as the medium level cloud, predominately altostratus and altocumulus, varied in cover and began to disperse at 1045 GMT. There were a few sunny spells, with crepuscular rays were seen to the S, but it was cloudier again by noon. Wintry showers were affecting NE England and these moved across Liverpool Bay. At 1300 GMT there was a flurry of snow; this was followed by several slight showers snow pellets and further snow flurries until 1530 GMT. Towards dusk the sky began to clear and there was clear sky and air and ground frosts at 20 GMT. [Rain trace; Max C; Min -1.2C; Grass -5.7C]
11th: With frontal cloud approaching from the W around midnight there was a small increase in temperature. The wind veered SE'ly and strengthened. At 0900 GMT the temperature was 2.7C (63% RH; dewpoint -3.5C) with the wind force 3/4 SE. Pressure 1014 mb was falling with low (970 mb) SW of Iceland. At 06 GMT occluded front was just W of Ireland, with developing triple point off Lands End tracking towards Brest. Rain was falling over Ireland (wintry precipitation in N reported), the SW where it turned to heavy snow on Dartmoor and into the Irish Sea. Here it was nearly overcast and dry; even the melted frost on the grass had dried off in the wind. Some bright spells during the morning with the maximum reaching 5.6C that was the lowest of the month. With falling pressure it became windier in the afternoon but kept dry until about 1700 GMT when slight rain turning to sleet arrived. Amounts of precipitation, intermittent sleet and sometimes snow, were small here but more fell on the Snowdonia Mountains, and ceased only after midnight. The night remained mostly cloudy. [Rain 0.3 mm; Max 5.6C; Min -0.4C; Grass -4.3C]
12th: A dull overcast morning. A sprinkling of snow was lying generally at 600 ft on the mountains, but reported to be almost down to the shore at Abergwyngregin. Pressure was 1000 mb with frontal low (998 mb) in the Bay of Biscay off Brest, with moderate snow over South Wales and on the Brecon Beacons where 12 cm snow was reported. Pressure was high (1040 mb) E Baltic. The morning was dull and grey with a few spots of rain at 1030 GMT that developed into intermittent slight rain from noon. Most rain was between 13 - 14 GMT, then there were some sunny spells before becoming overcast once more at 17 GMT. The night was mostly cloudy with a further shower of rain around 03 GMT followed by a touch of ground frost before dawn. (Precipitation amounts 06-06 GMT Plymouth 35 mm; Camborne 29 mm; Newquay 25 mm; Scilly Is. 15 mm; Milford Haven 13 mm). [Rain 1.0 mm; Max 7.8C; Min 1.4C; Grass -0.7C]
13th: With the low (1003 mb) moved on to the S North Sea pressure 1004 mb had risen and the wind veered SW'ly force 3. The sky was clearing after early showers with much cirrus above. Cumulus clouds were in the vicinity and over the mountains where they were already beginning to tower. Fresh snow, from early showers, was seen as low as 1000 ft on the Carneddau and near Ogwen with Snowdon obscured. As yesterday this would soon thaw but leave the longer standing snow beds at least for a while. Low (980 mb) SW of Iceland was deepening and moving rapidly E towards the N of the UK. The morning was bright with occasional sunny spells that lasted into the afternoon. From 1530 GMT there were blustery showers of rain, that were wintry on the mountains, with the wind increasing to force 5. Rain continued until 22 GMT. [Rain 10.4 mm; Max 10.6C; Min 2.8C; Grass -0.5C]
14th: Strengthening S'ly wind and more rain from 04 GMT turning moderate then heavy from 08 GMT. Rainfall for the past 24-h at 09 GMT was 10.4 mm with a further 4.5 mm by 10 GMT. There was more than 8 mm rain in the 2 hr (08 - 10 GMT) with water standing in puddles on the grass. Local roads were awash with water and the A5025 near Llansadwrn was partially flooded. At 09 GMT with the wind force 7 touching gale force 8 at times, before and after, pressure had fallen to 999 mb as the low (972 mb) approached the Western Isles of Scotland. Rain was falling over most of the W from Plymouth to Fort William. The rain and wind eased a little during the morning. Pressure remained low and steady until about 14 GMT when the wind veered WSW'ly and strengthened. There was a 0.6 m tidal surge measured at the POL Gladstone Lock Gauge on the afternoon tide (Liverpool 1649 GMT). There were some bright spells with a little sunshine. Dry overnight with the strong wind continuing. [Rain 4.4 mm; Max 11.2C; Min C; Grass C]
15th: Overcast with poor visibility. Pressure was steady on 1014 mb with low 980 mb) now Norwegian Sea and complex Atlantic low-pressure systems and fronts stacked up W of Ireland and over the Irish Sea. A mild night with the temperature on 9.0C at 09 GMT and a force 6/7 SSW'ly wind. There was soon a blustery shower of rain that led to more persistent rain by 1015 GMT to noon. More rain at 17 GMT that turned to showers before a spell of moderate to heavy rain from 2100 GMT to midnight. [Rain 12.2 mm; Max 11.0C; Min 7.0C; Grass 4.4C]
16th: Mist and drizzle after midnight, coastal and hill fog, and by dawn the wind had freshened. Overnight the minimum was 8.7C, the warmest of the month. At 09 GMT the SSW'ly was force 7 with a grey overcast sky with somewhat improved visibility (4 km) as the drizzle had ceased. Pressure was 1017 mb, with complex low-pressure centres (990 mb) to the NW, and closely packed isobars over Ireland and Irish Sea. The morning was dull and windy but it became brighter in the afternoon especially in the lee of the mountains and over the Menai Strait. Most of the island to the W and N remained shrouded in low cloud and mist. {Valley 0.0 h sunshine}. By 1800 GMT it was cloudier with the approach of a weak cold front. There was rain from 1930 - 2200 GMT with the rest of the night in low cloud and mist. [Rain 3.2 mm; Max 11.5C; Min 8.7C; Grass 8.4C]
17th: Today the weather station took part in the Great UK Weather Watch Day. Additional observations were made throughout the day and reported to the MetLinkInternational Weather Project. At dawn we were still shrouded in low cloud and mist but this started to lift and clear before 09 GMT. Low (972 mb) was near the Faeroes but pressure here 1022 mb was rising under the influence of high pressure to the S. The morning was bright with the sun shining through cirrostratus clouds. At noon a halo was seen around the sun. Cumulus clouds started developing over the Snowdonia Mountains from about 1030 GMT and a line of stratocumulus persisted well into the afternoon. The cirrostratus cleared and the convective clouds over Snowdonia diminished by 17 GMT. The sky cleared during the evening and dew formed on the grass. [Rain 0.0 mm; Max 12.5C; Min 6.9C; Grass 5.0C]
18th: A cloudy start to the day but there was some brightness just before 09 GMT. The buds on the horse chestnut have begun to open high in the tree. Pressure 1015 mb was falling as low (977 mb) SE Iceland tracked E. The cold front seen on yesterday,satellite image was over Ireland where there was some rain. The wind had backed S'ly and strengthened to force 5/6. The cold front passed over between 12 - 13 GMT ; there was a 3C temperature fall and 3 mm rainfall. The afternoon was showery with convective cumulus clouds in the vicinity and particularly over Snowdonia where there was some ice precipitation on the summits. At 18 GMT with pressure here 1011 mb frontal wave low (1001 mb) was deepening W of Ireland to (997 mb) by midnight when it was still W of Valentia. [Rain 13.8 mm; Max 10.5C; Min 6.0C; Grass 4.5C]
19th: At midnight pressure here was still 1010 mb but then started falling quickly to 994 mb by 06 GMT as the low (986 mb) tracked across Northern Ireland.. The SW'ly wind here had reached gale force 8/ 9. There was moderate to heavy rain from 02 GMT to 05 GMT on the warm front; the temperature was 6C but rose quickly to 9.7C at 07 GMT. The Britannia Bridge was closed to high-sided vehicles and a speed restriction placed on others. Some ferries out of Holyhead were cancelled. In a violent squall at 0730 GMT several trees were blown down, or trunks sheared off near the ground. One of the old trees on the Gadlys 'old cricket field' was uprooted, but was already dead! Gusts of 80 mph in North Wales were reported by Michael Fish in the weather report during the BBC Today programme . With passage of the cold front by 09 GMT the temperature had fallen again to 6.6C and pressure 996 mb had started to rise; the wind had veered W'ly force 6. There was some standing water at the weather station and a torrent of water seen falling above Cwm Idwal. There was a surge on the tide in the Cefni Estuary at 07 GMT 3 hours ahead of the high tide due at 1010 GMT. Driven on by the gale-force wind a large amount of rough water was rushing under Malltraeth Bridge into the River Cefni. Later in Liverpool, at the POL tide gauge at Gladstone Lock, an 0.8 m surge was measured. Although the river outflow was impeded on this occasion rainfall was not heavy enough to cause problems here, or on the Conwy River. The morning was bright between threatening clouds. By afternoon cumulus clouds were towering over the weather station and there was a light shower of small ice pellets at 1430 GMT. By evening the sky was overcast. At 18 GMT pressure here had risen to 1007 mb with the low (981 mb) in the W North Sea. There were further frontal wave lows (994 mb) S of Greenland just waiting to track across to soon give us more wind and rain. There was moderate rain from 2300 to 02 GMT and the temperature rose 3C between 0130 and 0230 GMT as we entered a warmer airflow. {Capel Curig 35 mm, Lake Vyrnwy 26 mm}. [Rain 4.6 mm; Max 10.0C; Min 5.7C; Grass 3.0C]
20th: It was quiet until about 03 GMT when the slates started to rattle. By 09 GMT with pressure 993 mb was falling quickly and the SW'ly was blowing force 8. Complex low (976 mb) was NW of Ireland tracking towards N Scotland. The storm cock was singing well while I was making the observations. He had been since first light, but he was singing on the sheltered side of the trees this morning! The temperature was 10.0C with 100% relative humidity; visibility was poor. With another high tide this morning another surge was expected. At Malltraeth it was higher than yesterday, but there was no flooding reported when it reached high point about 1040 GMT. At the POL tide gauge at Gladstone Lock, an 0.5 m surge was measured at 1100 GMT and a 1.4 m surge at low water at 1755 GMT. A very windy morning, with strong gusts with 66 mph being reported at Bangor Harbour and 70 mph at Aberporth, but little in the way of rainfall until a blustery shower at 1245 GMT. Pressure 990 mb had bottomed and the wind veered W'ly and again reached gale force 8/9 with more strong gusts. The afternoon then became sunny with an almost clear sky and the temperature reached 12.8C. Convective shower activity continued in the W; a shower at the rugby match in Lansdowne Road, Ireland where Ireland (who won) were playing Italy, spotted the TV lenses about 1445-50 GMT then crossed the Irish Sea to reach here at 1553 GMT. If this was the same shower it gives some idea of the speed of movement of the clouds today; distance travelled was about 88 miles. Trajectory analysis (HYSPLIT, NOAA ARL) seems to confirm that parcels of air arriving here were over Dublin just over an hour before arriving here. At Twickenham, Wales (who lost) were playing England. Otherwise it was a dry day with the precipitation not wetting the rain gauge bottle. Mostly cloudy at night becoming a little less windy by morning. [Rain trace mm; Max 12.8C; Min 6.3C; Grass 4.3C]
21st: Overcast at first as a line of shower clouds passed over, but no precipitation here, then brightening by 09 GMT. Pressure was 998 mb with the strong W'ly airflow continuing. The wind strengthened again to force 5 as the sky stated to clear. It is a drying wind; potential evapotranspiration from grass measured by lysimeter was 4 mm during the last 24-h. The morning was bright with sunny spells then cloudier with a little showery rain with a few small ice pellets about 1330 GMT. Further sunny spells later led to a partly cloudy night with a touch of ground frost.. As can sometimes be the way, we missed the results of the further development of the convective clouds over many parts of Britain. Shoppers in Manchester had to struggle against the wind while 40 rowers were left floundering in the Thames as 140 boats got into difficulty in strong winds and rough water. Elsewhere there were downpours of rain and hail together with thunder and lightning. In recent days 3 lives have been lost due to weather related events. [Rain 0.4 mm; Max 10.6C; Min 5.4C; Grass 2.7C]
22nd: A light fall of ice pellets at 0650 GMT then it became brighter. But there were cumulus clouds in the vicinity and some were already showing some moderate towers. Pressure 1013 mb at 09 GMT was rising and we were into the colder air with the wind veered NW'ly. High (1041 mb) was to the SW with low (988 mb) well to the N of Scotland. Showery troughs were lying over Wales and western Scotland. The morning was occasionally bright and although cumulus cloud built up it kept dry here. With rising temperatures the yellow flowers of celandines have appeared in the garden and along grass verges and sunny banks. Hedgerows are looking patchily white with flowers of the blackthorn which is still leafless. Hawthorn, that produces its leaves before the flowers, is starting to look green. Interspersed with blackthorn it results in the hedgerows looking patchy at this time of year. Catkins are hanging on hazel and the goat willow has flowers starting to open as well. Alexanders is also starting to flower and there are masses of primroses. In the greenhouse the buds of our Black Hamburg grape have opened. In the afternoon fresh snow was seen on Carnedd Dafydd above 2800 ft, the other summits remained obscured in cloud. It was clear at first after dark with a touch of ground frost but turned cloudier before midnight. [Rain 1.0 mm; Max 10.4C; Min C; Grass C]
23rd: There was a moderate shower around 04 GMT before the sky started to slowly clear. At 09 GMT with 4 oktas cover there was stratocumulus and cumulus clouds that were sometimes well-developed mainly confined to Snowdonia. Pressure 1019 mb continues to rise with high (1033 mb) forming S of Iceland. The morning was bright with cumulus clouds persisting. By noon convection had increased and there were cumulonimbus clouds over Caernarfon where there was rain about 1330 GMT. Although convection continued until late in the afternoon there was not rain here. The night was dry too although mainly cloudy. [Rain 0.0 mm; Max 8.5C; Min 3.0C; Grass -0.2C]
24th: A bright start to the day with convective cumulus clouds building up during the morning. Pressure was 1029 mb with the high (1043 mb) W of Ireland intensifying a little through the day. Again it kept dry with a moderate N'ly breeze. The temperature reached 8.6C by 1300 GMT. There was light snow on the summits of Carnedd Llewelyn and C, Dafydd at 2800 ft and on Snowdon at 2500 ft. The temperature indicated by the AWS was between -1.5C and -0.7C through the day. The end of the afternoon was fairly clear but it was becoming cloudier after sunset. Frontal cloud associated with a weak low (1011 mb) N of Iceland was lying to the NW and encroached during the night.[Rain 1.2 mm; Max 8.6C; Min 3.1C; Grass 1.0C]
25th: Light rain on the occluded front from 0315 to 0530 GMT followed by slight showers up to 09 GMT. Pressure 1021 mb had fallen with weak low (1018 mb) now in the North Sea. But the Atlantic-high W of Ireland was unchanged at 1043 mb. The morning was blustery, with a fresh NE'ly wind, and started to brighten by 1015 GMT. The afternoon became sunny as the sky cleared over Anglesey. With dry soils farmers were busy near the village ploughing fields in preparation for spring-sown crops. But dense cloud orographic wave clouds formations persisted over Snowdonia until late in the day (photographs and satellite image are within 8 minutes of each other). To the S there was more convection with hail showers being reported. The evening was clear, following a blood-red sunset, with dew forming on the grass and a touch of frost. [Rain trace; Max 8.8C; Min 4.0C; Grass 0.5C]
26th: Overcast at dawn as another weak warm front encroached from the NW. This was working its way round the high-pressure (1038 mb) still sitting W of Ireland. Here pressure 1027 mb had risen a little but despite this, just before 09 GMT, there was some drizzle from the moderately high uniformly grey stratus cloud. With the cloudbase above the mountaintops there was still a little snow seen above 2800 ft. Visibility was good with the mountaintops clearer than the Menai Strait, which had some inversion smoke. A band of light rain or drizzle, it was mainly drizzle here, moved down from the NE then pivoted and moved SE during the day. It kept overcast and the day was sunless. The night was similar with little or no wind. [Rain 0.2 mm; Max 8.0C; Min 2.5C; Grass -0.5C]
27th: Dull and still overcast with the low cloud hanging about 1500 ft on the N-facing slopes of the mainland mountains. It was lower, about 1000 ft, at the head of the Nant Ffrancon Pass. Visibility was good, and clear under the cloud. Pressure 1018 mb was falling as high-pressure to the W had declined with the high now (1038 mb) off Newfoundland. Shallow low-pressure was over the Mediterranean and North Africa. With pressure gradients slack there was little (NW'ly) or no wind. The day was very dull and sunless. The night was cloudy too but it was dry. [Rain 0.0 mm; Max 9.1C; Min 5.0C; Grass 5.8C]
28th: A clearer patch of sky just after dawn had closed over again by 09 GMT. As summertime (daylight saving) had started observations were at 10 am this morning. I was greeted by the first arrival here of the chiffchaff. Six days later than last year, possibly due to the N'ly headwinds. Anyway it was good to hear him again after the long journey from the Mediterranean area. A small olive-brown bird it is remarkable that they can travel up to 100 km a day. They sometimes arrive here on the same winds that bring Saharan dust. But not this year. At the moment with more dust storms in North Africa there are high concentrations of dust over the Mediterranean Sea. With a low (998 mb) over the Strait of Gibraltar the dust has been drifting NE. There is high pressure (1022 mb) over Europe and the Atlantic-high (1033 mb) appears to be stabilising again to the SW. Here it was 1016 mb and, with fronts lying to the NW and SE, it was a cloudy scene. The morning was cloudy at first but there were signs of some lifting and thinning then sun appeared by 1045 GMT. There was orographic cloud overhead at first in the afternoon but this cleared by 15 GMT giving a sunny end to the day with a maximum of 14.3C. Flowers have opened in the tops of ash trees, the leaves will appear later. In the garden buds on blackcurrants have burst open. Usually such buds and others are an attraction to bullfinches, but they have been absent this year so far. Soon after dark it became overcast. [Rain 0.0 mm; Max 14.3C; Min 6.2C; Grass 5.0C]
29th: Moderately high altocumulus cloud at first with a few breaks at 09 GMT. Pressure was 1022 mb with high over Wales. There was little (S'ly) wind becoming SW-W'ly later. Stratocumulus cloud persisted here but cleared on the W and N coasts, and on the Lleyn Peninsula, giving a largely sunny day. There was a partial clearance here about 16 GMT but had closed over again by 17 GMT. By the end of the afternoon the wind had turned 180 deg and become ENE'ly. A few clearer spells at night but not enough to give a frost. [Rain 0.0 mm; Max 12.2C; Min 5.8C; Grass 3.4C]
30th: The sky was clearing leaving cirrus and cirrostratus clouds by 09 GMT. Visibility was poor in thick haze; the sun rose at 0704 GMT (now well to the E of the mountains) a blood red colour then when higher in the sky turned milky white. The atmosphere was likely to contain Saharan dust blown across France and up the W coast of Ireland. There have been large dust storms in North Africa in recent days. Here it was sunny morning with a very light ENE'ly breeze. Pressure was 1018 mb with high (1026 mb) now S Norway to the Dardanelles. Complex low-pressure (990 mb) was in the Atlantic to the W and NW. The afternoon was sunny and warm with the temperature rising to 17.6C, warmest of the year so far, and the relative humidity falling to 44%, the lowest of the month. The evening and night were mostly clear with slight dew and no frost. {Solent MRSC 17.9C}. [Rain 0.0 mm; Max 17.6C; Min 4.5C; Grass 1.0C]
31st: A sunny but very hazy start to the day with a moderate ENE'ly wind. Although high-pressure (1029 mb) Norway to the Dardanelles was persisting, pressure 1006 mb here was falling as frontal-wave low (994 mb) was encroaching SW of Ireland. The sunshine was very milky, Saharan dust was still in the atmosphere at medium level while at low level (pollution) smoke haze was moving across from the Continent (clearly seen on the MODIS satellite image). Trajectory analysis (HYSPLIT MODEL, at NOAA ARL) indicated a parcels of air arriving here at 500 m at 12 noon was over the Czech/ Slovenia/ Hungary borders on the 29th before crossing Germany, Belgium, to be over London at 00 GMT before reaching here by noon. Another parcel arriving at 250 m (not shown), taking a more northerly route, was over Hannover at 00 GMT on the 30th then was over Rotterdam at 17 GMT before crossing the North Sea to reach here. At 1500 - 2000 m the air had come from North Africa via Sardinia and France. There was a dry deposition of a pinkish-grey dust, during the day. A little cumulus cloud at 09 GMT was building up overhead and over the mountains by 1015 GMT. A mostly sunny, hazy and warm day. Small tortoiseshell and peacock butterflies emerged from hibernation in good condition and were attracted to several flowering plants on the rockery banks in the garden. Altostratus cloud to the W in the afternoon did not stop the temperature rising to 19.1C, the warmest of the month. It was the warmest day in March since 1997, and the 3rd warmest in March on record at this station. Cloudier in the evening and night. {London, Northolt 20C}. [Rain 0.0 mm; Max 19.1C; Min 4.5C; Grass 1.5C]

April 2004

1st: An almost bright start to the day with a glimpse of the rising sun with orographic wave clouds seen overhead and to the W. By 0900 GMT the cloud had thickened and there were a few drops of rain by 0915 GMT. Pressure 1002 mb was falling slowly as frontal-wave low (982 mb) was tracking N just SW of Ireland. There was a trough lying Aberystwyth to the Wash. The morning was dull with some light rain at 1000 GMT that contained traces of dust. Trajectory analysis, using the HYSPLIT model on the NOAA ARL website, indicated a north-western Algerian origin just S of the High Atlas Mountains of Morocco. Dust was being raised on the 29th March (see MODIS AQUA satellite image) close to the indicated trajectory. The dust-laden parcel of air continued along the coast of Algeria before passing near the Balearic islands. It then crossed central France to reach here 500 m above ground to be washed out in the rain. The afternoon was a little brighter with 1 or 2 holes in the cloud, but they soon closed over again. The temperature of the soil at 30 cm depth reached 10.0C for the first time time year. Further light showers rain at 1600 GMT and just after midnight seemed clear of dust. [Rain 1.2 mm; Max 13.8C; Min 7.6C; Grass 6.9C]
2nd: A bright start to the day, blue sky with cirrus and cumulus. Only 3 oktas at 09 GMT but closed to 7 oktas by 1015 GMT. Pressure was unchanged on 1002 mb with complex low-pressure (989 mb) W of Ireland and low (986 mb) off Brest. High (1037 mb) was sitting over the Gulf of Finland. The day was mostly cloudy with some sunny spells and, in the afternoon, slight showers of rain with a rainbow seen at 1419 GMT. A little clearer around 21 GMT when the minimum temperatures occurred. [Rain 1.8 mm; Max 14.3C; Min 5.4C; Grass 2.3C]
3rd: A mild, sometimes windy night with blustery showers. Pressure 1003 mb was hardly changed with low (980 mb) S of Iceland and frontal systems crossing the UK. Pressure was high (1029 mb) over Spain and North Africa. The day continued blustery, with a fresh to strong SSW'ly wind, and cooler with a maximum of 10.3C. There was a spell of light rain from 1600 to 2030 GMT as a large area of rain affected SW England, Wales and NE England. Later it turned showery but there were some clear spells.[Rain 4.1 mm; Max 10.3C; Min 7.8C; Grass 5.1C]
4th: At dawn the sky was almost clear for a time with the temperature on the grass falling to 0.8C. It soon became cloudier and by 09 GMT was a complex of stratocumulus, altocumulus, cirrostratus and cirrus clouds. Pressure 1010 mb was rising, in a small ridge, but there was frontal cloud to the NW. Atlantic-high (1024 mb) was off Newfoundland while there was a low (994 mb) in the North Sea. The morning turned cloudy and blustery with a shower of rain at 1045 GMT. Another shower of rain and ice pellets at 1452 GMT. Precipitation fell as snow on the summits of the Snowdonia Mountains, where temperatures are below freezing again, and was lying above 2800 ft at 17 GMT. A dry but mainly cloudy night. [Rain 3.4 mm; Max 10.3C; Min 4.0C; Grass 0.8C]
5th: At midnight pressure was low (987 mb) Iceland and N North Sea while Atlantic-high (1030 mb) W of Ireland to Spain is intensifying. A showery W'ly airflow across the UK giving prolonged showers here from 0630 GMT. At 09 GMT pressure was 1010 mb and the W'ly was f3. The morning started dull with a little rain at times but was brighter by 11 GMT. Cloud developed again after noon and there was a heavy burst of rain with ice pellets at 1345 GMT. The rest of the afternoon was occasionally bright, but the sky did not clear until 17 GMT to reveal that most of the snow on the mountains had thawed. The clear sky did not last long, a touch of ground frost (-0.2C), as more clouds came across before midnight. [Rain 1.21 mm; Max 12.0C; Min 5.4C; Grass 2.3C]
6th: There was a shower of ice pellets at 0030 GMT with the sky remaining mostly cloudy. There was a touch of ground frost (-0.2C) 1 of 2 lowest of the month. At 09 GMT there was slight rain and moderately low cloud with poor visibility. Pressure 1009 mb was hardly changed with (1033 mb) to the W of Ireland and low (995 mb) over Denmark. We were still in the cool, showery NW'ly air flow. By 10 GMT there was a little sunshine breaking through and by the afternoon there were some good sunny spells. The sky almost clear before dusk became cloudier in the evening. [Rain 0.2 mm; Max 9.9C; Min 3.6C; Grass -0.2C]
7th: There was a slight shower of rain about 0330 GMT but by dawn the sky was clearing. At 09 GMT pressure was 1016 mb and the wind a moderate N'ly. A cumulonimbus cloud to the W over the Irish Sea had moved away but there were plenty of well-developed cumulus clouds in the vicinity. The first bluebell flower had popped up in the wood. The salt-tolerant ivy-leaved scurvy grass is now in flower along outer verge of the A5025 road Four Crosses to Pentraeth. It grows there because of the salt gritting undertaken during the winter months (see Wx-Watch report of last year). Convection lessened during the day and by afternoon it was mainly sunny. Again another almost clear sky by 17 GMT and after sunset a brilliant view of the 5 brightest planets. Mercury, Venus, Mars, Saturn, and Jupiter were all visible low in the western sky. It turned cloudier at times through the night with some showers around the NW coast. [Rain trace; Max 10.1C; Min 4.8C; Grass 2.0C]
8th: An overcast start with a light NW'ly breeze. It was dull and the cloud thickened given drizzle just before 09 GMT. Pressure 1022 mb had risen with the high 1034 mb) W of Ireland. The Baltic low pressure system (999 mb) was sinking slowly SE with a weak ridge (1017 mb) over Norway. We were now more within the compass of the Atlantic-high so wind speeds were less and drawing in air more from the NW than N. Light drizzle turned heavier for a while before clearing later in the morning to reveal a fresh covering of snow at 3000 ft across the Snowdonia summits. The day was mainly cloudy with only occasional glimpses of the sun. The evening and night were similar with little or no wind. [Rain trace; Max C; Min 3.1C; Grass 0.9C]
9th: Overcast with moderately high uniform cloud. The wind was now light Sly as, ahead of the front to the NW, there was a bulge of high pressure (1023 mb) over centred over South Wales. High (1035 mb) was still to the W while deep low (980 mb) was in the N Norwegian Sea. The day was dull and sunless with spells of heavy drizzle, or light rain from 1130 to 1230 GMT. There was further rain from 1630 to 1715 GMT. The maximum of 8.8C was 1 of the 2 coldest days in the month. [Rain 2.9 mm; Max 8.8C; Min 3.8C; Grass 1.7C]
10th: There were showers of rain from 02 to 03 GMT and it was very misty in the low cloud until dawn. Just before 09 GMT the sky had started to clear as the cloud lifted. The temperature was 8.5C, the warmest of the past 24-h, as the warm front passed. It was a little brighter, but there is an associated cold front over N England working its way S. Pressure was unchanged at 1020 mb with pressure high (1031 mb) to the W and low (989 mb) over Scandinavia. Bright at times in the morning and when the sun came out, with little wind, in a busy Beaumaris it seemed quite warm. The afternoon was bright with some sunny spells but was cloudier into the evening and night. [Rain 0.0 mm; Max 14.0C; Min 7.1C; Grass 7.0C]
11th: Overcast at dawn with poor hazy visibility there was overhead a break in the cloud at 0900 GMT. pressure was 1022 mb in a ridge of from Atlantic-high (1033 mb) to the SW. The morning was dull but the afternoon was brighter with sunny spells. Although there were some well-developed cumulus clouds nearby it kept dry. Again it was cloudy during the night which was mild. [Rain 0.0 mm; Max 15.5C; Min 7.5C; Grass 5.0C]
12th: A misty start to the day with visibility <200 m at 0630 GMT. A little clearer (< 1 km) by 09 GMT, but still overcast under stratus cloud with just a little NW'ly wind. Pressure 1027 mb continued to rise over the UK but it was a cloudy scene especially to the N. A mostly cloudy day but brighter in the afternoon with, later on, some sunshine over and S of the Menai Strait. It became very clear with fine views across to the Snowdonia Mountains. I could see only small, but frequent, patches of snow remaining on the flat top of Carnedd Llewelyn and rather fewer on Snowdon. The night was mainly cloudy. [Rain tr/dew; Max 13.0C; Min C; Grass C]
13th: A moderate dew on the grass and some on the raingauge funnels, it was overcast with moderately high stratocumulus cloud. The temperature was 9.1C with the dewpoint 7.2C (RH 88%). Pressure was 1027 mb with low (987 mb) Iceland and associated frontal system to the NW. It was raining over N Ireland and W Scotland. The day was dull and sunless with a light SW'ly breeze. There was a short spell of light rain from 1645 GMT as patchy frontal rain passed over. The night was overcast and dry here but low cloud and mist affected the mountains and coastal areas in the W of the island.. [Rain 0.4 mm; Max 13.5C; Min 6.0C; Grass 2.2C]
14th: Overcast and dull with a force 3 SW'ly wind. Pressure 1017 mb was falling slowly with frontal-wave low (992 mb) W of Ireland. It was wet in the N of Scotland. Here it was cloudy but dry; low cloud and mist was affecting the mountains. Brighter in the early afternoon with a little sunshine. But with the S'ly wind strengthening to force 5 it was overcast by 15 GMT but it kept dry until morning. [Rain trace; Max 12.4C; Min 8.3C; Grass 7.5C]
15th: Pressure had fallen to 1010 mb with low (975 mb) SE Iceland. The slow-moving front was over the Irish Sea and rain on it stretched from off Lands End through to Scotland. The wind was S'ly force 5/6 with a few spots of drizzle starting just before 09 GMT then moderate to heavy rain from 11 GMT. With the wind moderated by 15 GMT, 7 mm had accumulated, the most since 18 March. It was a cool day with the temperature not rising above the 8.8C at 09 GMT making it 1 of the 2 coldest days of the month. Slight rain continued until late in the afternoon. Mostly cloudy at night. [Rain 7.6 mm; Max 8.8C; Min 8.1C; Grass 7.0C]
16th: The sky started to clear after dawn, with the front edging S where it was still giving rain on a line from Birmingham to Plymouth, leaving cirrus clouds above the weather station moving quite quickly in a NE'ly direction. . By 09 GMT some cumulus clouds were seen to the W. Pressure was 1012 mb with high (1037 mb) W of the Azores and low (995 mb) over the Mediterranean. It rained in Nice all day but it was 16C. Here the 7.3C (81% RH) was pleasant as it was calm and sunny too. The Yr Wyddfa AWS, partially working again, was indicating -0.1C and had been -2.2C at 0615 GMT. With cloud and mist on the summits there was the possibility of some ice precipitation. The morning continued bright and sunny; forecasters were saying the front would move back over Snowdonia later in the day but it kept sunny here! The edge of the front remained almost stationary over the Menai Strait; rain continued to affect central parts of Wales and England. On the W coast of the island convergence convective clouds persisted most of the day. The evening and night were clear with inversion mist in the Menai Strait. [Rain 0.0 mm; Max 12.1C; Min 4.0C; Grass 1.0C]
17th: The overnight minimum temperature of 2.0C was the coldest of the month while on the grass it was -0.2C, 1 of the 2 lowest of the month. There was heavy dew (0.4 mm) on the grass. Clear at first by 09 GMT it was cloudier with a line of stratocumulus clouds just above the summits of the Carneddau, and a few fair-weather cumulus over Anglesey and approaching frontal cloud over the Irish Sea. Pressure 1002 mb was falling with low (976 mb) to the W of Scotland. A warm frontal system was over Ireland and W Scotland where it was already raining. When this reaches the Snowdonia Mountains, with temperatures hovering around freezing on the summits, there could be some wet snow. The SW'ly wind was force 5 here and likely to be greater on the mountaintops. The morning was sunny becoming windier. In the afternoon it had become overcast with the wind stronger at force 6/7. There were light showers of rain from 1325 GMT, with the approach of the rain band over the Irish Sea, and further intermittent rain from 16 to 06 GMT. With 11.4 mm rain it was the wettest day of the month. [Rain 11.4 mm; Max 10.5C; Min 2.0C; Grass -0.2C]
18th: Overcast and damp at dawn with the cloud becoming more convective before 09 GMT. Near the centre of complex low-pressure over the UK it was 979 mb here. Frontal cloud and rain was lying to the E while there was a line of showers running in off the Irish Sea on to Anglesey and the North Wales coast. It was a cool 6.5C but fell to 3.2C at 0937 GMT when there was a moderate shower of ice pellets. At Red Wharf Bay at 10 GMT there was a heavy shower of hail (>5 mm) that covered the ground and was still lying 30 minutes later. On the mountaintops, where temperatures were just below freezing, there was snow falling. The morning continued showery and snow was seen lying as low as 2000 ft on the mountains at noon. The afternoon had good sunny spells with the evening and night cloudier. [Rain 4.3 mm; Max 11.1C; Min 4.5C; Grass 3.9C]
19th: Mostly cloudy at dawn but clearing soon after so that at 09 GMT only 2 oktas cover. It was breezy with the W'ly wind force 5. Visibility was excellent with long-distant views possible of the Lleyn and Bardsey island. There was slight snow across Snowdonia summits with a little more around Snowdon. Pressure 987 mb was rising as low (972 mb) E Scotland moving away and filling. Further low pressure systems were to the W in mid-Atlantic; low (993 mb) was over the Ligurian Sea keeping the Mediterranean unsettled. The day was mostly sunny but cloudier in the afternoon when there was a shower of rain about 17 GMT. The evening was cloudy. [Rain 6.1 mm; Max 10.5C; Min 2.8C; Grass 2.7C]
20th: After midnight there were showers with some clear sky between. One heavier shower at 05 GMT contained ice pellets. At 09 GMT it was bright but there were plenty of shower clouds still in the vicinity. Pressure 999 mb was rising with the wind a moderate S'ly. Low (999 mb) was to the SW of Ireland, with associated fronts, deepening and moving NE. The day bright at first turned cloudier and milder by afternoon as frontal cloud moved north-eastwards. There was drizzle and light rain from about 16 GMT but this ceased after 2130 GMT. It was a mostly cloudy night but much windier after midnight. [Rain 0.5 mm; Max 12.5C; Min 5.3C; Grass 3.6C]
21st: Overcast with thin low cloud and the S'ly wind blowing at force 7. Pressure was 997 mb with low (967 mb) just to the W of Ireland. The cloud thinned during the morning becoming bright at times. The afternoon was cloudier with a slight shower of rain at 13 GMT and intermittent rain from 18 GMT to midnight. [Rain 3.4 mm; Max 13.5C; Min 8.6C; Grass 8.0C]
22nd: Still overcast at dawn the sky was clearing to cumulus clouds by 09 GMT. Pressure 1014 mb had risen with the low (984 mb) between Iceland and NW Scotland. High-pressure was lying to the W of Iberia and (1018 mb) over S Germany. The morning was bright with some sunny spells while the afternoon became increasingly sunny. With clear air visibility was excellent. While the sky cleared over Anglesey a line, or street, of stratocumulus cloud persisted over Snowdonia until 17 GMT by when they had dispersed. The evening was clear but it became partially cloudy later. . [Rain 0.0 mm; Max 15.1C; Min 7.8C; Grass 6.5C]
23rd: A mostly cloudy start to the day but there was a little sunshine at 09 GMT. The wind was S'ly force 3/4. Pressure was 1023 mb with high (1026 mb) Brittany to N Spain. But low (980 mb) was lying to the SW of Iceland and it's fronts were affecting the NW with rain over N Ireland and Scotland. The North Wales coast and the S were clear and sunny. The morning brightened before noon and there were some sunny spells. Later in the afternoon the cloud thickened and there were a few spots of drizzle. Mainly dry at night although drizzle occurred around some coastal areas. [Rain trace; Max C; Min 7.6C; Grass 5.7C]
24th: The sky had cleared by dawn leaving high cirrus and cirrostratus clouds. The overnight minimum of 9.5C was the warmest of the month. There was hazy sunshine and, with only a light S'ly wind, it felt pleasantly warm in the 13.8C. Low cloud and sea fog were affecting the W coast of the island with RAF Valley reporting 9C and light drizzle. Pressure was 1027 mb within the high-pressure centred over S Britain. Low (977 mb) was SW Iceland with warm front over the North Sea and cold front to the W. The day was sunny with the maximum reaching 19.8C, the warmest of the month. On the W coast and Menai Strait fog persisted and Valley's maximum was only 11C. The photographs show fog in the Strait near noon, with mountain tops clear, and sea fog at the Cob in Malltraeth in the afternoon. It was a clear evening and night. {London 23C, Cardiff, Liverpool 20C, Isle of Man 12, Valley 11C}. [Rain 0.0 mm; Max 19.8C; Min 9.5C; Grass 6.3C]
25th: Heavy dew on the grass with an almost clear sky and little or no wind. Pressure 1027 was unchanged. The day was sunny with smoke (pollution) haze visible on horizons. The wind was generally light S'ly. Occasionally, there was a sea breeze from the NE and some cumulus clouds formed overhead, they disappeared again when the S'ly resumed. The evening and night were clear and calm at times. [Rain 0.0 mm; Max 17.9C; Min 6.6C; Grass 3.6C]
26th: A clear and sunny start to the day. Visibility was good although there was moderate smoke haze. Pressure 1021 mb had fallen a little and frontal cloud was lying to the W of Ireland. The day was mostly sunny with the maximum rising to 18.9C. The west coast was affected by sea fog in the afternoon. There were thunder storms on a narrow line over the Midlands of England and South Wales during the day with some local heavy rain and flash-flooding. In Worcester 43 mm was recorded with water reported up to 3 ft deep in places. Ball lightning was reported seen over Brecon before a house was struck. Here, the mostly clear evening became overcast with thin cloud by 21 GMT, as the weak front encroached from the W, but it kept dry. [Rain 0.0 mm; Max 18.9C; Min 8.3C; Grass 4.4C]
27th: A cloudy morning with frontal cloud lying from Scotland through Wales to Lands End. But with some thinner and broken patches of cloud it was bright and dry. Pressure was 1019 mb with high (1031 mb) W of Ireland and shallow low-pressure (1011 mb) over France. A moderate NNE'ly breeze was bringing snow-like showers of bud scales of the now flowering sycamore trees. The day was mostly cloudy although there were some bright spells early in the afternoon. Later there were a few spots of rain and showery light rain about 20 GMT and in the night. Heavy rain in London caused cars to be abandoned and homes flooded. [Rain 1.3 mm; Max 12.4C; Min 7.8C; Grass 6.9C]
28th: Low stratiform cloud with some thinner patches by 09 GMT. Pressure was 1026 mb with the high (1033 mb) intensifying W of Ireland. Pressure was low (1006 mb) N France resulting in a moderate to strong (f5/6) NNE'ly airflow over the UK. Frontal cloud was lying almost as yesterday N England, Wales to SW England. The day was overcast with a little rain in the afternoon before it brightened, with a glimpse of sunshine, before evening; it was cool with the maximum only 9.8C. Mostly cloudy at night with a slight shower at 0230 GMT. [Rain 0.7 mm; Max 9.8C; Min 7.9C; Grass 7.6C]
29th: Another cloudy start to the day but it was to keep dry and be a little warmer. Pressure had fallen to 1010 mb with low-pressure between the Atlantic (1035 mb) and Sweden (1022 mb). A slow-moving front persisting across the Midlands gave a wet day in many parts to the S. Again the sky cleared a little at the end of the afternoon but soon became overcast once more. [Rain 0.0 mm; Max 11.5C; Min 6.6C; Grass 5.3C]
30th: A little brighter this morning with some blue sky between cumulus clouds (6/8) at 09 GMT. Pressure 1006 mb had fallen a little more with a low (980 mb) over the Bat of Biscay. The wind, ENE'ly force 4, felt cool with the temperature on 9.5C. Cloud was moderately low across the Snowdonia Mountains in good but hazy visibility. The day was mostly cloudy but bright at times with a little sunshine; smoke haze developed through the day. There were some clear moonlit periods in the late evening but it was cloudier after midnight. [Rain 0.0 mm; Max 12.5C; Min 6.6C; Grass 6.6C]

May 2004

1st: A cloudy but bright morning with hazy sunshine breaking through by midmorning. Visibility was poor with thick smoke haze including Saharan dust that had blown over the Mediterranean Sea and through E Europe and across the North Sea. There was a trace dry deposition of light coloured dust and pollen grains on top of the Stevenson screen and the sky looked very milky. Pressure was 1008 mb with low (999 mb) over the Bay of Biscay and an associated cold front lying over S England. There were early thunderstorms in London and the SE and a line heavy showers of rain affecting the Bristol Channel and S Midlands during the morning. Here, the day was mostly sunny with a light NE'ly breeze. The evening and night were mostly clear. [Rain 0.0 mm; Max 14.6C; Min 8.7C; Grass 7.9C]
2nd: Mostly clear at dawn with mist in some low-lying areas. There was moderate dew on the grass but the temperature did not go below 3.5C. Pollen deposition, no dust observed although the blue of the sky was still rather milky. Hazy sunshine at first but cumulus clouds developed by 09 GMT. Pressure was 1009 mb and the temperature 11.8C. It was calm with the occasional puff of wind from variable directions. Isobars were slack with filling low (1004 mb) still over Biscay and Atlantic-high (1032 mb) S of Greenland. The morning was bright and the afternoon mainly sunny. Frontal cloud encroached during the evening and there was a little rain around midnight. [Rain 0.7 mm; Max 16.1C; Min 6.3C; Grass 3.5C]
3rd: A bright morning with well-developed cumulus clouds by 09 GMT. Pressure was 1005 mb with low (982 mb) over the Norwegian Sea. But low (993 mb) was SE Greenland and by noon was SW Iceland and had deepened to (986 mb) and was on-track for the Irish Sea. Despite the threat of showers the day was mainly sunny and dry along the North Wales coast, especially in the afternoon, with clear views across to the Snowdonia Mountains. By evening frontal cloud associated with the low (979 mb at 18 GMT) off NW Scotland had arrived. By midnight the low had deepened to (973 mb) and there was rain from 2345 GMT that, with the SW'ly wind strengthening to force 7/8. With pressure 983 mb falling quickly the Oregon storm alarm sounded at 0240 GMT. The rain was moderate to heavy through to 05 GMT accumulating 20.7 mm by morning. It was heavier over the mountains with Capel Curig reporting 35 mm by 06 GMT. {Prestatyn 10.4h, Valley 7.0h}. [Rain 20.7 mm; Max 14.8C; Min 6.6C; Grass 5.3C]
4th: At 06 GMT the low was (971 mb) over the Western Isles of Scotland. This low pressure is unusual and particularly so in May; the lowest on record is 969 mb at RAF Sealand, Flintshire, back in 1943. Sealand, once a civil airfield, was taken over in 1916 and used for training and later as a communications support for RAF operations around the world. The station is under threat of closure in April 2006. After the passage of the triple-point front the weather had become showery. There was a heavy burst of rain and ice-pellets at 0630 GMT (the only hail in the month) before there was a brief clearance. By 09 GMT with well-developed cumulus clouds in the vicinity pressure 977 mb was still falling. The morning was bright with a few short sunny spells. Low-pressure caused a tidal-surge of about 0.5 m, measured by the Proudman Oceanographic Laboratory at Gladstone Lock, Liverpool. As convective cumulonimbus clouds increased in the afternoon there were frequent showers of rain. Temperatures on the summits of the Snowdonia Mountains were just below freezing and precipitation was sometimes of snow. Pressure reached its lowest 973 mb about 18 GMT. Later the sky cleared and shallow fog formed on the fields by 21 GMT briefly shining white in the moonlight. It soon clouded over and there was more showery rain. [Rain 5.0 mm; Max 11.1C; Min 6.5C; Grass 5.5C]
5th: Minimum temperatures overnight of 3.5C in the air and 0.6C on the grass were the lowest of the month. A dull and damp morning with low stratocumulus cloud covering the sky; it was at 1500 ft across the mountains. Low (973 mb at 06 GMT) was anchored just to the N of here. Pressure 997 mb had started to rise and there was a light NW'ly wind. The morning was dull with a few spots of rain at times. Things were different in Rhyl where a cloudburst around 0945 GMT contributed largely to the recorded {29 mm}, reversing the usual rainfall gradient as here and Valley {3.4 mm}. While the afternoon had occasional glimpses of sunshine at first there were frequent light showers later. Showers continued through the night. The large low-pressure system was encompassing most of the Mediterranean and bringing unsettled wet weather far to the S including Italy and Greece. {Rhyl 29 mm, most in the UK}. [Rain 7.1 mm; Max 12.2C; Min 3.5C; Grass 0.6C]
6th: With the low (987 mb at 06 GMT) still anchored in the Irish Sea showers continued to be brought in on the cool NW'ly wind. At 09 GMT pressure here was 990 mb and continuing to rise slowly. Here the morning was dull and overcast with low stratus with slight rain at times. By 11 GMT it was a little brighter as the cloud lifted and mostly cleared over Anglesey in the afternoon. A line of stratocumulus clouds persisted over the Snowdonia Mountains. There was snow on the top of Carnedd Llewelyn and around Snowdon. The low had up-anchored about noon and was tracking slowly NW. By 17 GMT the wind had backed SSW'ly and strengthened to force 4. The evening and night were clear with dew forming on the grass and low-lying mist across the fields. [Rain 0.1 mm; Max 13.2C; Min 6.3C; Grass 4.6C]
7th: By midnight the low now (997 mb) was near Rockall, W of Scotland. Mist thickened in valley bottoms but started to clear at dawn. The sky was still clear but by 09 GMT cumulus clouds had developed and cumulonimbus were seen to the S over the mountains. Pressure was 1004 mb and continuing to rise with the wind a light NW'ly. Pressure was low (989 mb) over E Germany and the Mediterranean continues unsettled. A warm front was lying over the North Sea and this was expected to move W during the day. There was sea fog on the Irish Sea that affected the N and NW coast of Anglesey and the Llyn Peninsular. The day was bright and warmer with some good sunny spells in the afternoon. Later approaching warm front, unusually from the E, encroached slowly. There was rain on a line through the Cumbrian coast, Manchester and London at 21 GMT, but it would not reach here until morning. [Rain 0.6 mm; Max 15.0C; Min 5.1C; Grass 1.3C]
8th: There was rain from just after 06 GMT but it was slight and had accumulated only 0.6 mm by 09 GMT. There was a trace of grey dust deposited. Pressure was 1007 mb with low (993 mb) over the Netherlands. With the slow-moving warm front over Wales cloud was a uniform grey stratus hanging low on the Snowdonia Mountains and coasts. Visibility was good at first but misty at low level with hill fog at higher descended later. The day was wet, with slight or light rain at times and poor or very poor visibility. The night was similar with the rain easing to drizzle by morning. Very little variation in temperature, from 8.7 at 09 GMT to a maximum of 9.8C next morning, the lowest of the month. [Rain 5.7 mm; Max 9.8C; Min 7.0C; Grass 5.4C]
9th: Low cloud mist and fine drizzle. There had been a deposit of grey dust overnight. Pressure was 1009 mb with the warm front still in the vicinity with low Germany (1002 mb) filling. Low (1005 mb) was W of Brest. Very poor visibility and 99% humidity the fine drizzle continuing in the morning but eased by noon. The afternoon became brighter as cloud thinned and eventually, towards evening, the sun broke through. At dusk, about 21 GMT low mist started to form on the fields and fog (visibility <100 m) after midnight.[Rain trace; Max 13.3C; Min 8.7C; Grass 8.4C]
10th: Fog at dawn (visibility <100 m) began to clear before 09 GMT when it was very poor (1 km). The sky was obscured and there was 100% relative humidity at 10.3C. Pressure was 1015 mb with high-pressure (1024 mb) building W Shannon, Ireland, and (1016 mb) over Tunisia. Pressure was low (996 mb) over the Baltic and (1009 mb) over the Mediterranean. There was a weak N'ly airflow across the UK. The morning was misty but this lifted to give a bright and mostly sunny afternoon with the temperature reaching 17.0C. A clear evening but turning misty before midnight. [Rain mm; Max 17.0C; Min 6.5C; Grass 5.0C]
11th: There was fog (<100 m visibility) from 03 GMT to 09 GMT. Pressure 1021 mb continues to rise but the fog was slow to clear during the morning remaining near some coasts and offshore during the day. In the afternoon there was a small clearance overhead, with just a glimpse of sunshine, but it was soon gone. From S Snowdonia to the W of England it became sunny and warm, convective clouds developed setting off thundery showers. Here another misty night. {Warmest, Cardiff 21C; Sunniest, Tenby, Pembrokeshire 12.5h}. [Rain 0.2 mm; Max 12.0C; Min 8.0C; Grass 5.3C]
12th: Mist and a fine wetting drizzle this morning. Little or no wind; the pressure 1025 mb had risen further in ridge from Atlantic-high (1029 mb) to the SW. But lows SW Iceland and to the W of the high-pressure have a lot of frontal cloud associated with them. Here the low stratiform cloud and sea fog from St George's Channel into Cardigan Bay and the Irish Sea persisted around coasts, and over the island, keeping the day dull, cool (12.2C in the morning was the highest) and damp. S Snowdonia saw some sunshine with the cloud clearing but Scotland had the best weather. {Glasgow 18C, Stornoway, Western Isles 13.7h}. [Rain trace; Max 12.7C; Min 9.2C; Grass 9.3C]
13th: You guessed it! Still dull and grey but the visibility had improved to moderate and the relative humidity was down to 86%. So it was no longer mist. The point where classification changes is 95% RH. Above it is mist or fog, below it is haze, but there must be exceptions to this rule I think! Pressure had risen to 1024 mb but was steady. My Oregon barometer has been forecasting sunshine for days. Today it is cloudy. The forecast in these instruments is an algorithm based on the rate of change of barometric pressure. (It has been rising so sunshine was forecast; now it is steady cloud is forecast). Usually it is quite good but is caught out, as in past days, when there is cloud trapped within a high-pressure system. Occasionally the cloud thinned and just before 09 GMT the temperature was 12.7C, the warmest of the past 24-h. It has closed over again and there is a light NNE'ly breeze. The morning stayed dull but in the afternoon discreet cumulus clouds developed with some sunny spells. To show what we have been missing the temperature popped up to 17.0C. By evening it was overcast again giving a warm night with the temperature not going below 10.5C. Rain 0.0 mm; Max 17.0C; Min 9.0C; Grass 7.4C]
14th: An overcast morning with a light W'ly breeze. Visibility was good with a little haze. Pressure 1025 mb was rising again with the high (1028 mb) to the SW. But there was much frontal cloud to the NW affecting N Ireland and Scotland while it was clearer, and sunny, to the S. The Oregon barometer is back to showing sunshine, so we can hope! It stayed mostly cloudy in the morning, but sunny spells developed in the afternoon when cloud lifted, thinned and partly dispersed over Anglesey. Stratocumulus clouds remained over Snowdonia. By evening it was overcast again remaining so overnight. [Rain 0.0 mm; Max 17.8C; Min 10.5C; Grass 10.0C]
15th: Dull and overcast at first but by 09 GMT breaks were appearing and altocumulus clouds formed. Pressure was 1031 mb within the high over SW Britain. It was a warm 15.0C with a light SW'ly breeze. The morning was mostly sunny but it was cloudier here from noon as convective clouds developed nearer the Snowdonia mountains. Over most of Anglesey it was sunny including Point Lynas where maritime spring flowers were in full bloom. Sea birds seen included Gannet, Tern and Fulmar as well as Chough. By the end of the afternoon the sky cleared everywhere and it was a clear night. [Rain 0.0 mm; Max 18.5C; Min 11.2C; Grass 9.1C]
16th: The first clear start to the day for a while. There was heavy dew on the grass (0.43 mm measured by lysimeter), calm at first there was only variable breezes at 09 GMT with a temperature of 17.0C (dewpoint 10.9C). Visibility was good impaired a little by smoke haze. Pressure was 1032 mb within the UK high-pressure enlarged now to include most of France! The day was sunny and warm with the temperature reaching 22.3C with a range of 13.6C, sunshine was the maximum possible (14.4h at Valley). The evening was clear. [Rain 0.0 mm; Max 22.3C; Min 8.7C; Grass 5.6C]
17th: It was becoming cloudier at dawn but the was a little sunshine at first. At 09 GMT it was overcast with pressure on 1027 mb. Deepening low (985 mb) NW Norwegian Sea had a front lying Scotland and Ireland. Pressure was low (1008 mb) over the Mediterranean where it continues unsettled. The morning was overcast at first, but dry, and the cloud dispersed by noon with the afternoon sunny over most of Anglesey. The cold front, decaying all the time, was seen to the N from Tywyn Aberffraw Dunes early in the afternoon (see photo and satellite image) and was overhead at 16 GMT and had passed S in less than 2 hours. The evening and night were clear. [Rain 0.0 mm; Max 19.2C; Min 9.6C; Grass 6.0C]
18th: A clear dawn here but around the western coast there had been mist and fog since before midnight. Before 09 GMT cumulus clouds had appeared (3/8) and were being blown along on a force 3 SW'ly. Pressure 1027 mb was unchanged as high (1028 mb) remains to the SW. The remnants of yesterday's front was over the SE end of the English Channel; there were some more to the NW likely to moved across over the next days. The morning was mainly sunny, and with the cloud dispersing the afternoon and evening were clear and sunny. Interesting thermal image indicates temperatures of sea and on land. Water is relatively in the Irish Sea warming slightly to St George's Channel and is warmer in Cardigan Bay and along the North Wales coast. The grey to the N of Anglesey is the advancing frontal cloud. N part of Anglesey is cooler as are the mountains. Cooler water too in the Bristol Channel and E English Channel (extends into the North Sea), while the warmest is off N and S Devon coasts. The colours over South Wales are due to small convective clouds. [Rain 0.0 mm; Max 18.8C; Min 8.6C; Grass 4.6C]
19th: A clear night at first but frontal cloud from the N encroached at dawn and by 08 GMT it was overcast. Within an hour breaks had appeared and it was brighter with a little sunshine but was short-lived. Pressure was 1025 mb and the temperature 15.2C. The wind was light W'ly and visibility good. By noon it was overcast again, with the front slow-moving, and in the afternoon there were some spots of drizzle and a slight shower of rain. A cloudy evening and night. [Rain trace; Max 17.0C; Min 9.4C; Grass 5.9C]
20th: Overcast at dawn but brighter with breaks appearing at 09 GMT. Pressure was 1024 mb with high (1034 mb) to the W and complex low-pressure (991 mb) over Scandinavia. This was giving a cooler N'ly airflow across the UK. The slow-moving cold front was still lying just to the S of here. The morning was mostly cloudy with a light N'ly wind; by the afternoon it was sunny but the day's maximum was only 13.5C. The evening and night, clear at first, became cloudier by morning. [Rain 0.0 mm; Max 13.5C; Min 9.7C; Grass 9.4C]
21st: A cooler night with the temperature on the grass 4.0C. Overcast at dawn but soon clearer as cumulus clouds formed. At 09 GMT some were well-developed especially over the mountains of Snowdonia. Pressure was 1025 mb with the high (1032 mb) just W of Ireland. The temperature was 9.8C while on the summit of Snowdon it was 1.4C but had been as low as 0.1C at 0530 GMT. If the convective clouds had produced any precipitation it might have been wintry! The morning was bright with sunny spells and the afternoon was sunnier with the cloudbase high over the mountaintops. Another cool day with a maximum of 12.2C. A mostly clear evening and night. [Rain 0.0 mm; Max 12.2C; Min 6.6C; Grass 4.0C]
22nd: After a cool night with dew forming on the grass cumulus clouds started to appear by 08 GMT. At 09 GMT pressure was 1030 mb with high (1033 mb) NW of Malin Head, Ireland. The morning was bright with good sunny spells and a cool NE'ly breeze. Some cumulus built up overhead in the afternoon, the result of convergence between warmer SW'ly and cooler NE'ly air, before dispersing by 17 GMT. A clear evening and night. [Rain 0.0 mm; Max 15.0C; Min 5.8C; Grass 3.4C]
23rd: Clear at dawn but 5/8 cloud had formed by 09 GMT. Pressure was 1030 mb and there was a light S'ly breeze. It was warmer (15.0C dewpoint 8.1C) with the moderate dew on the grass drying quickly. Visibility was good with some smoke haze and the morning mostly sunny (2/8). In the afternoon cumulus clouds again developed overhead (6/8) restricting the amount of sunshine. It was slow to disperse but had done so by 1730 GMT. Valley reported {14.9h} sunshine (no clouds on the west of the island!) while the Isle of Man reported the most {15.3h}. A clear evening and night. It was the 15th day without rain (unmeasurable trace amounts and 1 day with 0.1 mm on 11th can be ignored; a rain day needs 0.2 mm, or more), so according to old definitions (introduced by G. J. Symons in 1887) it is possible to declare an 'official absolute drought'. [Rain 0.0 mm; Max 18.2C; Min 6.3C; Grass 3.3C]
24th: It was overcast at dawn with moderately high cloud (5000 ft). At 09 GMT there were some breaks appearing with some sunshine developing. Pressure was 1028 mb with the high (1030 mb) centred on Ireland. With the cloud mostly clearing it was a sunny day, some well-developed cumulus clouds formed to the S around noon but cleared by mid-afternoon. A clear evening and night. [Rain 0.0 mm; Max 17.6C; Min 6.5C; Grass 3.4C]
25th: After some mist and fog patches around the coast at dawn, clearance of some moderately high cloud, it was a bright and sunny morning. Pressure was 1025 mb with the high (1027 mb), now over the Western Isles of Scotland, being squeezed by deepening low (979 mb) SE Greenland and low-pressure (1007 mb) over Scandinavia. The day was sunny although there were some well-developed cumulus clouds over the mountains of Snowdonia in the morning. A clear evening and night with dew on the grass and some mist in low-lying areas. It is now 17 days without significant rainfall. It is the driest spell in May since 1980! [Rain 0.0 mm; Max 13.9C; Min 6.8C; Grass 4.6C]
26th: The sky was still clear at dawn (now about 03 GMT) and the birds have their first sing from about 0310 GMT, usually the song thrush and blackbird that have nests near the weather station. It was still almost clear (1/8) at 08 GMT but by 09 GMT cumulus clouds had developed and it was mostly cloudy (6/8). The temperature was 13.7C approaching yesterday's maximum (13.9C) with little (S'ly) or no wind. Pressure 1020 mb was falling with the remnants of the high (1025 mb) over the Orkney islands. Low (972 mb) was off SE Greenland with slow-moving cold front W of Ireland. Pressure was low (1010 mb) over the Baltic. The morning was bright but it became increasingly cloudy by afternoon. It was warm with the temperature reaching 18.0C, but sunshine was only occasional here between slow-moving cumulus clouds. On the west coast it was sunny with RAF Valley reporting {13.4h}. By evening the cloud dispersed leaving a hazy night. [Rain 0.0 mm; Max 18.0C; Min 3.3C; Grass 6.2C]
27th: An almost clear sky and little or no wind; the temperature was 15.5C with 65% relative humidity at 09 GMT. Pressure of 1021 mb was steady but low (986 mb) was still SE Greenland but expected to move E, with associated frontal wave low off SW Ireland, cloud into the W by this evening. The morning was sunny with good but hazy visibility. By noon there were some cumulus clouds in the vicinity, but with continued sunshine the temperature reached 22.7C, the highest of the month. The evening was mostly clear but approaching frontal rain was over St George's Channel by 21 GMT and reached here by morning. [Rain 1.0 mm; Max 22.7C; Min 7.5C; Grass 4.3C]
28th: Overnight the minimum temperature was 13.0C, the warmest of the month. There was light rain from just after 05 GMT and by 09 GMT there was 1.0 mm to measure. This broke the 18-day drought and there was more light rain during the morning. At 09 GMT pressure was 1020 mb and there was light rain falling. At noon low (987 mb) was SW of Iceland with a weak cold front over Wales with an occluded front over Ireland. By afternoon the rain had ceased and it was, for a time, bright with a few sunny spells between the fronts. Typical of frontal rain in high-pressure systems the amount was small and did little to restore soil water balance. It was overcast again by 17 GMT but there was no further rain measured until after midnight. [Rain 2.2 mm; Max 18.1C; Min 13.0C; Grass 11.0C]
29th: There was drizzle or very slight rain from 0230 to 0630 GMT. Pressure was 1018 mb there were signs of the sky starting to clear in a light S'ly breeze. Moderate visibility was improving but there was mist and low cloud on the lower slopes of the Snowdonia Mountains. The morning became brighter and the afternoon sunny, as most cloud eventually cleared, leading on to a clear evening and night. There was a large fire on Mynydd Bodafon on Anglesey that destroyed much gorse and heather heath during the day. Following a smaller fire in the morning it took 20 fire-fighters over 5 h to put out the larger fire. [Rain 0.0 mm; Max C; Min 12.5C; Grass 9.9C]
30th: There was some stratiform cloud at first which developed into cumulus by 09 GMT. Pressure was 1019 mb with slow-moving and filling low (993 mb) S of Iceland; there was a complex frontal system and showery troughs over the UK. The morning was mostly sunny with a S'ly breeze, while the afternoon was mostly cloudy at first but the sky cleared before evening. The night was clear. [Rain 0.0 mm; Max 18.1C; Min 9.3C; Grass 5.8C]
31st: Clear from dawn until 08 GMT when cirrus cloud encroached from the SW. Soon cumulus clouds developed, but it was sunny and warm in between and at 09 GMT was 15.8C (dewpoint 10.1C). There had been 0.3 mm dew measured at 08 GMT, but this had already dried off. Pressure was 1017 mb with weak low (1005 mb) SW Ireland, associated warm front bringing rain on a line from Galway, through the Pembrokeshire islands, to Exeter. By 10 GMT the sky was almost overcast with moderately-high, thin cloud. The afternoon was dull with cloud thickening and there were spots of fine rain from 1745 GMT. The radar had shown rainfall here from 1545 GMT but it was evaporating before reaching the ground. There was light rain from 1830 GMT, with a heavier burst around 2230 GMT, turning to drizzle by at 0030 GMT. [Rain 3.7 mm; Max 16.7C; Min 8.6C; Grass 6.2C]

June 2004

1st: A dull morning with low stratiform cloud giving hill fog on the lower slopes of the Snowdonia Mountains. Low (1012 mb) was just to the S and pressure here was 1015 mb. A ridge of high-pressure from Azores-high (1030 mb) was to the SW but further fronts, associated with low (995 mb) off Newfoundland, lay to the W. The morning was overcast and dull, but with pressure rising the cloud cleared over Anglesey leaving a line of stratocumulus clouds over the mountains of Snowdonia. The night was clear at first with a bright near full moon. [Rain 0.0 mm; Max 17.2C; Min 11.4C; Grass 11.0C]
2nd: It was a mainly cloudy morning, some high cirrus and towering cumulus clouds at 09 GMT. Pressure 1028 mb had risen within a ridge of a high-pressure over S Ireland. There was a mass of frontal cloud to the NW, associated with weak low-pressure to the SW of Iceland, moving towards Scotland. The morning was bright and by afternoon, with the cloud dispersing, it was mainly sunny. The evening clear at first became overcast by 21 GMT as cloud encroached from the NW. [Rain 0.0 mm; Max 15.6C; Min 7.5C; Grass 5.0C]
3rd: Overcast but bright at first with the sun occasionally seen behind thinning stratiform cloud. Light rain was reported early on the W of the island and at 09 GMT darker cloud was seen to the W. Pressure was 1028 mb with low (1006 mb) SW Iceland with associated fronts affecting Scotland, North Wales and Northern Ireland. Pressure was high (1033 mb) to the SW off Brest, Brittany. There were spots of rain here at 0950 GMT and a spell of moderate rain, with a few heavier bursts, from noon to 1615 GMT before turning to drizzle. At 17 GMT in low cloud there was moderate fog (visibility <500 m) becoming denser through the evening. It was thick (<100 m) at 19 GMT until around midnight [Rain 4.8 mm; Max 15.5C; Min 10.8C; Grass 8.8C]
4th: A damp and murky morning but visibility had improved to good (>10 km), but there was low cloud and mist on the lower slopes of the mountains. There was light rain around western coasts and on the mountains. Pressure was 1024 mb with high (1029 mb) to the SW of the British Isles. Deep low (987 mb) S Greenland has an associated cold front in the Atlantic W of Ireland. A warm front, intruding over Ireland and North Wales, is responsible for the low stratiform cloud and rain. There was clear skies within the high over the Bay of Biscay, W France and Spain. There was sea fog in the Irish Sea and over land the low cloud persisted all day and into the night with long spells of slight fine drizzle. [Rain 0.1 mm; Max 16.8C; Min 13.1C; Grass 12.0C]
5th: More of the same, dull and damp with again spells of slight fine drizzle. Pressure was 1022 mb with the high (1023 mb) positioned just SW of Lands End on the 06 GMT chart. There was little (WNW) or no wind, but visibility was good. Sea fog and low stratiform cloud affected the North Wales coast, Snowdonia Mountains and Cheshire. The day kept overcast, the cloud thick enough for specs of drizzle in the morning. The afternoon was drier with thinner cloud and it did begin to clear from 19 GMT so there was some sunshine in the late evening. The sky was clear at night until dawn. [Rain trace; Max 18.4C; Min C; Grass C]
6th: Cloudier from dawn with a little sunshine at first. But by 08 GMT the low cloud was rolling in again and at 09 GMT there was just a glimpse of the sun through thickening cloud. Around the coast there was fog and low cloud at 30 m. Pressure was 1019 mb with low (1000 mb) S of Iceland; there was a cold front over Ireland and Scotland. Pressure was high (1022 mb) over Belgium. A cloudy and dull morning with the afternoon becoming brighter with glimpses of the sun. At evening the sky cleared. [Rain 0.0 mm; Max 18.5C; Min C; Grass C]
7th: A bright and sunny start to the day here. But to the W low cloud fog could be seen; this had been affecting coastal areas through the night. RAF Valley reported fog and light drizzle at times. Pressure was 1018 mb with frontal cloud lingering over Morecambe Bay. High (1025 mb) was over S Europe while low (1008 mb) to the N over Shetland. The morning was sunny with a S'ly breeze, with very good and clear visibility. The afternoon was sunny and warm, but as a high plume of dust arrived from North Africa visibility became hazy. During the evening cumulonimbus clouds developed over the Ireland and the Irish Sea and tracked across and N of Anglesey. The was a shower of large spotted rain in Bethel at 1845 GMT. Sea fog also encroached from Red Wharf Bay; around 1852 GMT fog was seen flowing SW across the A55 Expressway, down the shallow Afon Cefni valley across Malltraeth Marsh. At the same time a slow-moving cumulonimbus was traversing the island in the opposite direction just to the S. Thunder was heard at the weather station at 1942 GMT, there were large spots of rain and a rainbow seen soon afterwards to the S. Lines of sferics were seen as the storm clouds developed across Ireland and the Irish Sea (Valley reported thunder at 21 GMT. [Rain trace; Max 20.3C; Min 12.4C; Grass 11.3C]
8th: A murky start to the day with mist and low stratiform cloud. Pressure was 1015 mb with complex low-pressure (992 mb) to the W of Ireland. The morning, and afternoon at first, were overcast. It did brighten late in the afternoon, when there were glimpses of the sun; 6 painted lady butterflies were seen in the garden. [Rain 0.7 mm; Max 18.0C; Min 13.9C; Grass 13.0C]
9th: Mostly cloudy at night with mist around the coast and mountains. There was rain from 06 to 0730 GMT, then sunny spells developed by 09 GMT. Pressure was 1017 mb with low (1002 mb) off Malin Head to the NW that had a cold front N Ireland, Wales and Lands End. Another low (994 mb) was W of Ireland. The morning was bright and breezy (SW'ly force 5) with sunny spells. Somewhat cloudier in the afternoon but it was mostly thin and as a result bright at first. By 1730 GMT cloud was thicker and there were a few spots of rain. The night was mostly cloudy and mild. [Rain 0.6 mm; Max 19.8C; Min 13.6C; Grass 12.8C]
10th: Showery rain from 03 to 05 GMT. At 09 GMT still mostly cloudy (7/8) but soon brightening. Pressure was little changed on 1015 mb with twin low-pressure centres (977 mb) to the NW of Ireland. We were in a warm showery SW'ly (force 5) airflow with the overnight minimum 14.2C, the warmest of the month. The day was bright but there was not a lot of clear sunshine. The wind rose to force 6/7 in the afternoon tearing leaves and branchlets from trees. Several branchlets from the beech trees, complete with ripening nuts, were found on the ground. Dark clouds appeared by evening; cumulonimbus storm-clouds moved in a line NE'wards past South Stack during the evening, intense sferics were recorded offshore. There was a slight shower here at 2200 GMT. [Rain 0.1 mm; Max 18.7C; Min 14.2C; Grass 12.9C]
11th: A bright start to the day with the WSW'ly wind moderated to force 4. Pressure at 09 GMT was 1017 mb with low (1004 mb) to N Scotland, where there was moderate rainfall, and high (1026 mb) to the SW in Bay of Biscay. A little sunshine in the morning with cumulus clouds developing in the vicinity. Bright at first in the afternoon, especially in the W of the island, but cloudier later with showery rain from 1500 to 1800 GMT. A further slight shower at 2230 GMT before a dry but cloudy night. [Rain 2.0 mm; Max 17.2C; Min 10.5C; Grass 8.9C]
12th: Cloudy at first with some breaks appearing at 09 GMT. Pressure 1023 mb had risen with high (1029 mb) just to the SW. With low-pressure (1002 mb) over the Baltic there was a cool NW'ly airflow. During the morning some good sunny spells developed over Anglesey and it was a mainly sunny afternoon with a maximum of 16.9C. In the evening the sky had cleared and was so during the night. [Rain 0.0 mm; Max 18.6C; Min 10.8C; Grass 8.9C]
13th: A sunny morning with small amounts (2/8) of cirrus and cirrostratus cloud. There were small cumulus clouds around the summits of the Snowdonia Mountains. Visibility was very good in clear air. Pressure 1032 mb had risen with intensified high (1034 mb) off S Ireland. The temperature at 09 GMT was 18.6C (dewpoint 12.2C) already exceeding that of yesterday. There was a moderate to fresh at times S'ly wind; the temperature rose in the afternoon to 22.8C. By evening it was cloudier, with mostly thin moderately high cloud, the tail of frontal cloud lying to the NE. The night was partly cloudy with some clear spells. [Rain 0.0 mm; Max 22.8C; Min 9.5C; Grass 6.3C]
14th: A bright morning with sunny spells between cumulus clouds. Pressure was unchanged 1032 mb with the high (1035 mb) near Valentia, S Ireland, showing little sign of moving off. With rainfall of only 8.4 mm so far this month the potential water balance of the soil is -15.6 mm, so the soil surface is quite dry. There are no signs of water stress on trees and pasture grass locally, but the vegetables on the garden plot have needed some irrigation. Vegetation on some shallow soil areas, fixed sand dunes, rocky places and coastal cliffs, is beginning to look dried. The morning was mainly sunny and warm, and by afternoon with the sky clearing the temperature rose to 23.6C, warmest of the month and year to date. A clear evening, with a peach and azure blue coloured sky, and night keeping light until after 22 GMT. [Rain 0.0 mm; Max 23.6C; Min 14.1C; Grass 12.4C]
15th: It was still clear at dawn, about 03 GMT but became cloudy as a weak cold front encroached from the N. At 09 GMT it was overcast and dull with poor visibility. Pressure 1027 mb had fallen a little with slow-moving high (1032 mb) to the SW now declining. The day was sunless but dry with the cloud thickening; there was a little drizzle at 2030 GMT that just dampened the ground. A cloudy and mild night. [Rain 0.1 mm; Max 18.0C; Min 12.0C; Grass 10.0C]
16th: Overcast with uniform stratiform cloud. It was also hazy with poor visibility. But it was still warm with the temperature on 17.3C (dewpoint 15.1C). Pressure 1021 mb had fallen with high (1031 mb) in mid-Atlantic. Low (1006 mb) to the W of Scotland, the warm front over the N was giving rain in N Scotland. The same front was hanging over North Wales but it was dry. The morning kept overcast but by afternoon, with the sky clearing quickly, it was sunny with the temperature rising to 21.6C. A clear evening by cloud encroached by midnight. [Rain 0.0 mm; Max 21.6C; Min 13.0C; Grass 12.8C]
17th: With the low (1000 mb) N North Sea it was overcast with a fresh WNW'ly wind. At 0900 GMT with pressure on 1012 mb it was a little cooler on 13.5C (dewpoint 10.9C). During the morning the cloud was tending to break up and there were a few brief sunny spells. There was a clear spell in the afternoon, when the temperature rose briefly to 19.8C, before clouding over again. With the dry spell continuing vegetation has suddenly turned yellow along roadside verges, and grass around rocky outcrops. Water baths in the garden have been in great demand by all species of bird including great spotted woodpeckers, magpie and crows. While the tits find plenty of grubs in the trees blackbirds have been in serious trouble feeding their young, the ground being too dry and sources under leaves being largely exhausted. I have not seen any fledged blackbirds, but thrushes have been successful being able to find plenty of snails. The evening and night were overcast. [Rain 0.0 mm; Max 19.8C; Min 12.0C; Grass 9.3C]
18th: Overcast at first but by 09 GMT the cloud was broken (6/8) and there were sunny spells. Pressure was 1011 mb, and with high-pressure (1029 mb) to the W and low-pressure (996 mb) S Baltic, the wind had turned N'ly. It was the coolest morning with 12.5C since the 1st June. It was showery to the N with a patch of rain to the E around Newcastle, but here cloud dispersed further during the morning. The rain kept to the E and we had another fine, dry day with some sunshine in the afternoon. It was cool, with a maximum of 15.0C. A clear evening and most of the night. {Glasgow 27 mm; Copley, Co Durham 13.5 mm}. [Rain 0.0 mm; Max 15.0C; Min 10.0C; Grass 8.2C]
19th: Some dew on the grass at 06 GMT that had dried off by 09 GMT. After one of the now seemingly rare clear nights the minima of 5.8C and 3.4C on the grass were the coolest of the month. It was becoming cloudier as a trough moved down over the Irish Sea from the N. pressure was 1011 mb with high (1025 mb) drifting towards S Greenland. Pressure was low (995 mb) S Norway maintaining the cool N'ly airflow. The morning was mainly cloudy, the temperature at 09 GMT 10.8C, the coldest since 21 May. It was cold enough on Cairngorm Mountain in Scotland for snow to fall during the day, but it is over 4000 ft high. The afternoon here became brighter here but there were showers about; the Carnival at Benllech was caught in a 5 minute shower. The sky almost cleared towards evening, but then cloud encroached rapidly and there was intermittent slight to moderate rain from 2100 to 0200 GMT. {Aviemore, Highland 20 mm} [Rain 3.3 mm; Max 14.0C; Min 5.8C; Grass 3.4C]
20th: The overnight rain of 3.3 mm brought welcome relief to our parched garden; the plants and lawn responded quickly already looking brighter and greener by 09 GMT. Pressure was 1007 mb with the high (1021 mb) now S Greenland, joining Greenland blocking high (1026 mb). Low (994 mb) was over S Sweden, slightly deepened. Associated frontal cloud was lying to the N on the 06 GMT chart. There were further showers of rain during the morning, but by afternoon it was sunny at times before turning cloudier for the evening and night. {Camborne 12 mm, Manchester 10 mm, Capel Curig 6 mm}. [Rain 0.5 mm; Max 16.8C; Min 6.4C; Grass 4.2C]
21st: Partly cloudy from dawn (about 03 GMT) when the birds were starting to sing. Just before 09 GMT with thicker cumuliform clouds there were light showers. The soil surface was slow to wet-up but just made it at observation time. Pressure was 1008 mb with low-pressure system developing to the SW and on-track for St George's Channel at 00 GMT on Wednesday. Pressure was high (1027 mb) Greenland. A line of showers was over North Wales associated with the low (1000 mb) S Norway. The morning was showery with prolonged moderate to heavy rain from 0930 to 1115 GMT giving most of the 5.5 mm rainfall for the day. The afternoon was dry but remained quite dark under a persistent line of stratocumulus cloud. The maximum temperature during the day was only 13.2C. The sky did clear by evening when there was some sunshine. The night was clear. [Rain 5.5 mm; Max 15.7C; Min 8.3C; Grass 5.6C]
22nd: A bright, sunny and warmer morning; the temperature at 09 GMT was 15.7C the highest of the past 24-h. Relative humidity was down to 59% in a light S'ly breeze falling further to 52%, the lowest of the month. There was cirrostratus, cirrus and altocumulus cloud early with some cumulus development by midmorning. Pressure 1009 mb was still steady although deepening low (995 mb) was to the SW of Ireland. There was moderate rain on frontal cloud ahead of the low approaching SW England. But it took a long time to reach here. With thickening cloud there were some spots from 15 GMT, with the E'ly wind strengthening to force 4/5, but nothing much until 1830 GMT when rain was light to moderate until 0100 GMT. Being, on this occasion in the rain shadow area of the Snowdonia Mountains, rainfall was only 6.4 mm. (Highest rainfall 06 to 06 GMT was Milford Haven 41 mm with Isle of Man 27 mm, Aberdaron 25 mm; Capel Curig 23 mm; Valley 22 mm; Pentraeth 6.3 mm) [Rain 6.4 mm; Max 18.7C; Min 6.7C; Grass 3.8C]
23rd: Pressure was lowest 985 mb about 05 GMT and at 09 GMT was starting to rise (986 mb) with the low (982 mb) over Cardigan Bay at 06 GMT. It was one of the lowest depressions recorded in the month of June in the UK. There were showers in a light N'ly wind having backed from SE'ly yesterday. The morning gradually brightened and by 11 GMT there were sunny spells within the clear 'eye' of the storm, but they did not last as the 'comma' cloud rotated. By noon it was overcast and dull with drizzle or light rain at times lasting through the afternoon. The NW'ly wind freshened to fresh to strong, occasionally near gale force 7. There was a spell of moderate rain from 1700 to 2200 GMT before the night became dry keeping overcast and windy. [Rain 7.5 mm; Max 17.0C; Min 11.3C; Grass 9.6C]
24th: Mainly cloudy with the strong NW'ly wind making the 11.2C temperature at 09 GMT feel rather cool. Pressure 1005 mb was rising slowly with the low (987 mb) over the North Sea reluctant to move away. A ridge of high-pressure to the W started to move across later, but another low (1002 mb) S of Greenland was following. The day kept cloudy with slight showers at times. Heavier ones were at 1300 and 1630 GMT. With thick cloud all day the temperature did not get above 13.1C, the coolest since 12th May. The 24-h maximum of 13.7C was the coolest of the month. In the evening as pressure rose the sky started to clear and there was some sunshine. It was a clear night. [Rain 1.8 mm; Max 13.7C; Min 9.6C; Grass 8.9C]
25th: A clear start but soon cumulus clouds bubbled up and by 09 GMT it was 6/8th cover. But there was sufficient sunshine to start raising the temperature and it was 13.7C, exceeding yesterday's. Pressure was 1017 mb with with high (1021 mb) S Brittany. Low (986 mb) SW of Ireland was tracking NE. The morning was bright with a little sunshine, but the sky was clearer away from the influence of the Snowdonia Mountains. By noon it was mainly sunny, with clear skies over Anglesey, a line of stratocumulus clouds persisted over Snowdonia, mainly westward over Llyn mountains, less so over the Carneddau. The night was mainly clear until after midnight. [Rain 0.9 mm; Max 18.0C; Min 6.4C; Grass 4.0C]
26th: Frontal cloud was encroaching at 0330 GMT when there was a fine red sky. Due proverbial warning was given to sailors and shepherds of approaching rain. Drizzle before 0530 then light rain from 08 GMT accumulated 0.9 mm by 09 GMT. Pressure 1010 mb was falling with twin lows (978 mb) W of Ireland. The wind force 3/4 at times was SE'ly backing S'ly. The morning continued overcast with rain soon easing, but the afternoon kept overcast. By evening the sky cleared; later remnant low stratiform cloud came in off the sea and remained most of the night. [Rain 1.0 mm; Max 17.5C; Min C; Grass C]
27th: Overcast at first but soon breaking up and forming cumulus clouds that were traversing quickly in the force 5/6 SW'ly. Some clouds were towering over the Snowdonia Mountains. Pressure was 1014 mb with low-pressure (980 mb) to the NW and high (1024 mb) over the Mediterranean. We were in a brisk SW'ly airflow with the morning quite sunny, between the passing clouds. During the afternoon some dark clouds came over with 2 light showers but there was good sunshine in between. The evening was clear. [Rain 0.2 mm; Max 18.7C; Min 13.3C; Grass 11.5C]
28th: The night was clear and cool at first but became cloudier around 06 GMT. Pressure 1023 mb had risen in a ridge from high (1030 mb) in the Bay of Biscay; the SW'ly wind was force 3. During the morning the cloud started to disperse it becoming mostly sunny. The afternoon was sunny at first before the SW'ly wind strengthened to force 5/6 as frontal cloud encroached from the NW. There was a slight shower at 1515 GMT the a spell of moderate rain from 1800 to 1900 GMT. There was heavy rain over the mountains of central Snowdonia around 20 GMT. The night was mostly cloud but dry. [Rain 3.8 mm; Max 18.3C; Min 8.0C; Grass 4.5C]
29th: Overcast with low stratus and mist at 09 GMT. Pressure was 1022 mb with low (984 mb) to the NW and fronts over Ireland and to the W. The morning was dull but the cloud was lifting and thinning by midmorning, after a shower just before noon the afternoon was dry, sometimes bright, but the sky did not clear. Cloud thickened after midnight. [Rain 9.4 mm; Max 17.1C; Min 11.5C; Grass 9.8C]
30th: Light showers after midnight preceded a spell of rain from 0400 GMT. Some heavy pulses of rain crossed Snowdonia (Snowdon AWS recorded 5.6 mm/hr at 07 GMT) and Anglesey; there was 9.4 mm rainfall by 09 GMT. This rainfall, credited to the 29th, was the wettest 24-h period of the month. Pressure 1008 mb was falling with low (982 mb) just SW of Iceland. Light rain or drizzle was still falling in the low stratiform cloud with 100% relative humidity. The wind was a blustery SSW'ly force 5/6 but the rain gave way to light showers with a few glimpses of the sun. Soon the temperature had reached 18.4C about 1300 GMT there was a heavy shower of 2.5 mm that fell in minutes as the temperature dropped 4.7C to 13.7C. Afterwards the temperature did rise again but only to 15.5C. The night was mainly cloudy with light showers continuing. [Rain 3.5 mm; Max 18.4C; Min 12.9C; Grass 12.2C]

July 2004

1st: Early light showers of rain with cumulus clouds in the vicinity at 09 GMT. Pressure was unchanged at 1008 mb with the filling low (988 mb) W of Scotland. Frontal cloud of yesterday had moved briskly to be over S Scandinavia, Baltic and Denmark, but we were still in a very showery W'ly airflow. The morning kept dry with shower clouds passing by on the force 4/5 WSW'ly wind. The cloud lifted during the afternoon that was brighter but without clear sunshine. The evening and night remained mostly cloudy with the cloud thickening later. [Rain 0.3 mm; Max 16.4C; Min 9.3C; Grass 7.1C]
2nd: A light shower at 04 GMT continuing slight but blustery up to 09 GMT with a frontal trough passing over. Pressure was 1005 mb with low (993 mb) off the Western Isles of Scotland. Associated occluded frontal cloud was over Ireland. The morning continued blustery in a force 5/6 SW'ly wind; with some breaks appearing it was a case of some sunshine and further showers. The afternoon was dry at first with the cloudbase rising to almost clear the mountain summits for a while. But shower clouds soon returned and were frequent by 1700 GMT until just after midnight. [Rain 1.9 mm; Max 17.0C; Min 11.0C; Grass 9.9C]
3rd: Low stratocumulus clouds causing hill fog on the mountains with showers developing by 09 GMT. Pressure 1009 mb was rising with the low (998 mb) over the North Sea just off Dundee in Scotland. Pressure is high (1030 mb) over the Atlantic S of Greenland. There was a slight shower at the weather station at 0915 GMT with the morning remaining mostly cloudy. The wind was still fresh (f5) but had veered W'ly. There were some sunny spells in the afternoon but some slight showers also. A cloudy evening with a moderate shower about 2130 GMT with the rest of the night dry. [Rain 1.4 mm; Max 18.1C; Min 11.0C; Grass 10.0C]
4th: Pressure 1012 mb was rising very slowly under the influence of high (1031 mb) S of Greenland. But complex low-pressure N Scandinavia (998 mb), and North Sea (1003 mb) off Aberdeen, was resulting in a NW'ly airflow. Remnant frontal cloud was lying just to the N and the morning was mostly cloudy with the odd bright spell. The blackbirds at the weather station have, at the 3rd attempt, raised a brood of young (Diary 17 June). They were helping themselves to ripening raspberries in the garden! With the dry weather earthworms are still deep in the soil, but the parents are able to find more other food now that there has been some rain. At 09 GMT the temperature was 15.0C (dewpoint on 11.7C) with a moderate NW'ly wind. It was another day of some sunshine and occasional slight showers (1615 GMT) under the darker clouds. It was sunnier away from the mountains with Valley reporting {5.5 h}. The night continued showery with light showers about 2100 and 0100 GMT. [Rain 0.3 mm; Max 17.8C; Min 11.2C; Grass 7.1C]
5th: Overcast at first but bright with sunny spells at 09 GMT. The overnight minimums of 8.1C and 5.2C on the grass were lowest of the month. Pressure was 1021 mb but there were showery troughs to the NW with a developing low SW of Iceland. There were cumulus clouds in the vicinity that were well-developed over the mountains. The morning was sunny with the clouds tending to diminish as the wind backed to the SSW. The afternoon was sunny and warm with the temperature rising to 20.0C. During the evening moderately high cloud encroached from the W. [Rain 0.0 mm; Max 20.0C; Min 8.1C; Grass 5.2C]
6th: Cloud broke up after dawn and had formed cumulus (cloudbase 335 m reported at RAF Valley) with some altocumulus (457 m) with cirrus (6096 m) at 09 GMT. There were sunny spells and it was warm at 17.0C in the light SW'ly breeze. Pressure was 1022 mb with high (1023 mb) Wales, but frontal low to the NW of Ireland was closeby and thundery low over Spain was threatening to move N. The morning was sometimes sunny with well-developed cumulus in the vicinity. The afternoon was mostly cloudy with the wind backing ENE'ly. On the W coast it kept sunny until late afternoon. Showers of rain were reported from the Conwy Valley and Llanfairfechan during the day. With a covering of cirrostratus cloud a complete 42° solar halo, with partial colouring, was observed from Aberffraw from 1440 to 1435 GMT. Thunderstorms moved up to Snowdonia during the evening and thunder was heard from 2220 to 2320 GMT. There was a shower of rain at 2330 GMT. [Rain 3.3 mm; Max 17.6C; Min 10.1C; Grass 6.3C]
7th: There was rain from 0130 to 0600 GMT but at 09 GMT there were a few small breaks appearing in the moderately high stratocumulus clouds. Pressure was 1017 mb with thundery low (1001 mb) S Brittany. A ridge of high-pressure (1027 mb) was extended from the Atlantic towards N Scotland. The wind was a light NE'ly at first, but this strengthened as the day progressed. In the lee of the Snowdonia Mountains some cloud dispersed at times giving clearer spells. The day was bright with some hazy sunshine. [Rain trace; Max 17.4C; Min 11.3C; Grass 10.5C]
8th: A windy start to the day the NE'ly at force 6 had stripped some leaves and branchlets from the trees. A large flock of housemartins and swallows were seeking insects low over cattle grazed grass on fields to the W of the weather station in the lee of the trees. Pressure was 1012 mb with Brittany low (992 mb) tracking slowly NE. Rain had moved up through Wales mostly SE of Snowdonia to N England with only a few drops here around 09 GMT. Winds were strong to gale-force in the English Channel and S North Sea. Here it was bright at times at first during the morning, as the sun appeared through thinner patches of cloud, but it was raining by 1050 GMT. With the temperature falling quickly from the maximum 13.5C the lowest of the month (the 4th lowest in July) the rain was 'sleety' with ice pellets, only the 2nd record in July (1993) at the station. From then it was down hill with rain at times and a temperature around 11.4C through the afternoon. Heaviest rain was at 1600 GMT when most of the 6.6 mm was recorded. The night was cloudy. [Rain 6.6 mm; Max 13.5C; Min 11.7C; Grass 11.1C]
9th: A brighter morning, with the NNW'ly wind moderated to force 2, the sun was appearing through cloud thinning at times. Pressure was 1014 mb with the low (1003 mb) over the North Sea and remnant high-pressure (1021 mb) in a complex W of Ireland. The day was mainly cloudy but bright at times with glimpses of sunshine. With the wind from a N'ly direction orographic cloud persisted over the station and could be seen on the satellite image fanning out over the mountains through Wales into S England. Elsewhere around Anglesey it was mainly sunny. After a few spots of rain about 17 GMT the evening was sunnier when the cloud dispersed. [Rain trace; Max 18.0C; Min 9.7C; Grass 7.5C]
10th: After dawn the sky was clear and dew formed on the grass (grass minimum 8.3C) but before 09 GMT convective clouds developed quickly and were towering in the vicinity. Pressure 1014 mb was unchanged with low (995 mb) over the Baltic with occluded front over Scotland giving some rain to the N of here. The morning was mostly cloudy with a shower of light rain at 1045 GMT. The afternoon was overcast, with occasional fine drizzle, this extending into the night. [Rain 0.3 mm; Max 16.1C; Min 10.6C; Grass 8.3C]
11th: Very dull and still the fine drizzle from time to time that was not wetting concrete. Pressure at 09 GMT was 1014 mb with frontal cloud masses over Scotland and to the W over Ireland. The day continued overcast the cloud thickening from time to time to give more fine drizzle. There was a somewhat heavier spell about 1600 GMT that did wet the ground. Similar at night, cloudy with fine drizzle at times. [Rain 0.6 mm; Max 16.6C; Min 10.2C; Grass 7.8C]
12th: Another dull and damp start to the day with cloud persisting in the light NW'ly wind. Pressure 1017 mb was rising as a ridge of high-pressure to the W was moving over the Irish Sea. Low (990 mb) was over the Baltic while the Azores-high (1028 mb) was indented by frontal-low (1013 mb) to the W of Ireland promising more unsettled weather during the week. The morning remained mostly cloudy and dull but brightened during the afternoon with sunny spells before evening. On the N coast of the island it was sunny most of the afternoon, with clearer sky spreading slowly S. The sky cleared here during the night. [Rain 0.0 mm; Max 16.3C; Min 10.4C; Grass 8.0C]
13th: Clear sky at first but cloudier (6/8) by 09 GMT. But the cloud mostly cirrostratus at first was thin and high so that it was bright and sunny. Pressure was 1017 mb in a ridge of high-pressure crossing from the W. Cumulus clouds developed and there was a persistent line of stratocumulus over the mountains of Snowdonia during most of the afternoon. Anglesey was mostly clear of cloud with Valley reporting {11.7 h}. The light S/SW'ly breeze strengthened during the day becoming force 4/5 later, but did not prevent the temperature rising to 20.8C. By evening frontal cloud had encroached from the W and there was rain, moderate to heavy at times, from 2245 to 0345 GMT. This was the most rainfall in 24-h since the 3 May (20.7 mm). Llanbedr with 25 mm saw the most rain. {Southport 13.1 h sunshine}. [Rain 13.7 mm; Max 20.8C; Min 9.0C; Grass 5.8C]
14th: A dull and damp start in warm moist air behind the warm front that passed through in the night. A cold front was over Ireland associated with low (980 mb) SW of Iceland. Cloud was low over Snowdonia with hill fog on the lower slopes. The day was dull, damp and dismal with cloud thick most of the time. There was light to moderate rain from 2100 to 0100 GMT then intermittent heavy drizzle with thick fog (visibility <100 m) until about 06 GMT. [Rain 3.9 mm; Max 17.0C; Min C; Grass C]
15th: Under low stratus cloud it was calm at 09 GMT. Pressure 1014 mb was unchanged with wavy frontal system stretching right across the Atlantic N of the Azores to central Wales and on into N Europe. It seemed to have a few anchors down, including 1 in the Irish Sea I think, as it was so slow-moving. Low (991 mb) was still SW of Iceland too. Strongest jetstream winds were positioned just N of the frontal system, and over N UK, likely to be leading to large-scale cloud formation and the unsettled weather pattern. There was further drizzle during the morning before a band of rain moved across the Irish Sea giving rain here from 1100 to 1500 GMT. The rain was heavy (>4 mm/ hr) around 1230 GMT. During the evening there was thick fog (visibility <100 m), in relatively warm air, but this cleared away before midnight. {Llanbedr, Gwynedd 20 mm}. [Rain 11.0 mm; Max 15.6C; Min 13.6C; Grass 13.8C]
16th: A dull and misty start but there was some brightness at 0900 GMT as low cloud thinned. Pressure was 1013 mb with low (994 mb) S of Iceland. The wavy frontal system was still lying across the UK with little improvement in the weather. During the morning the sun broke through on 1 or 2 occasions, when it felt warm in the light NW'ly wind, but it was covered up again very soon. After noon the cloud mostly cleared and there were good spells of sunshine. Later frontal cloud encroached and there was rain from just before midnight that turned heavy around 0100 GMT and 0715 GMT accumulating 18.3 mm, wettest of the month and the most since 3 May (20.3 mm). [Rain 18.3 mm; Max 17.7C; Min 13.5C; Grass 11.0C]
17th: Continuous light rain at 09 GMT turning to heavy drizzle later. There was low cloud and mist during the morning. Pressure was 1009 mb with the wavy front again lying over North Wales. Weakened low (993 mb) was just off the Western Isles of Scotland, but pressure was high (1022 mb) to the SW offering some hope of an improvement soon. Deep convective storm clouds over SE England developed thunderstorms with hailstones up to 12 mm diameter were reported in SE London during the morning. By afternoon the sky was clearing here and there was some sunshine. During the evening the sky cleared to give a fine night. [Rain 0.3 mm; Max 18.7C; Min 10.9C; Grass 10.5C]
18th: A clear start but convective clouds had formed by 09 GMT giving 5/8th cover. Pressure was 1014 mb within a minor ridge of high-pressure . Most cloud dispersed over Anglesey except a line of convergent stratocumulus N-S across the island persisting until the afternoon, and over the mountains where the line persisted all day. The SW'ly wind kept at force 3/4 but the temperature rose to 20.2C for most of the afternoon but cooler around the coasts. The evening was mainly clear with dew forming on the grass. [Rain 0.0 mm; Max 20.2C; Min 10.2C; Grass 6.8C]
19th: A bright but mostly cloudy start to the day with banded cirrus high above passing small cumulus clouds above the weather station. But over the mountains there were well-developed cumulus clouds with cirrostratus cloud encroaching from the S. Pressure was 1015 mb with the ridge moving E and complex low-pressure system to the W. Showery troughs were giving some rain to the NW and SW, but the morning here kept mostly sunny with a force 4 S'ly wind. The afternoon was bright at first but cloud had thickened by 1500 GMT when there was rain until 1930 GMT. After a heavy shower at 2250 to 2300 GMT (3.0 mm or 18 mm per hour) the night kept dry. [Rain 9.2 mm; Max 19.4C; Min 11.4C; Grass 9.0C]
20th: A bright morning with cumulus clouds over the mountains. Pressure 1010 mb was falling as deepening low (1000 mb) to the SW of Ireland approached. Associated fronts brought early rainfall in the W with just a few spots falling here by 1400 GMT, but not before the temperature had risen to 21.0C. The S'ly wind freshened to force 5 and there was a spell of showery rain from 2230 GMT to about midnight. [Rain 2.0 mm; Max 21.0C; Min 12.8C; Grass 12.2C]
21st: A mild night with the minimum on 14.1C and a bright but breezy start to the day with the SSW'ly was force 4/5. Pressure 1011 mb was rising again although there was complex low-pressure to the NW (995 mb), with another low (1006 mb) was in mid-Atlantic. The day was mostly sunny with a maximum of 20.2C. The evening was clear but the night became cloudier after midnight. [Rain 0.0 mm; Max 20.2C; Min 14.1C; Grass 13.2C]
22nd: Dark grey skies under moderately low cloud heralded a damp and cool day. Low (997 mb) was W of Scotland with slow-moving frontal cloud over the Irish Sea. There were spots of rain at 0920 GMT then light rain from 1130 and moderate rain from 1300 to 1515 GMT. But the total accumulated was only 2.5 mm. By late afternoon it brightened from the W and there was a little sunshine in the evening before turning cloudier again. [Rain 2.5 mm; Max 16.4C; Min 13.5C; Grass 11.7C]
23rd: A cloudy dawn but by 09 GMT it had broken up and formed cumulus clouds that allowed warm sunshine in between. The temperature on 16.4C had already reached yesterday's maximum. The low was filling (1000 mb) and moving N with high-pressure (1023 mb) building from Brittany across the SW and S Ireland where the skies were clearing. Low (1008 mb) was W of the Iberian peninsula. The morning was mostly sunny with a moderate to fresh SW'ly wind, but there was a lot of cloud lying just to the NW. The afternoon was clear and sunny on Anglesey (maximum 20.6C) with some cumulus remaining over Snowdonia. The evening sunny at first became cloudier later as frontal cloud edged down from the NW. [Rain 0.0 mm; Max 20.6C; Min 12.8C; Grass 11.1C]
24th: Overcast and dull. Pressure 1026 mb was rising but a mass of cloud was being brought down from the NW, the probable result of the jet stream's current position. The morning was dull, but dry with a moderate SW'ly wind and was the best of the day with a maximum of only 15.8C. It was different in the S where they are having summer weather. Cloud was thicker here in the afternoon and there was a little rain during the evening. With large sunspots active at the moment a geomagnetic storm developed after midnight generating aurora; cloudy here of course. {Southend (Essex) 25C and 14.4h sunshine; (Scottish Highland) Tulloch Bridge 13C Aultbea 16.8 mm} [Rain 3.9 mm; Max 15.8C; Min 10.6C; Grass 7.6C]
25th: Moderate rain from 0730 GMT with a heavier burst about 08 GMT. Low cloud with mist at 09 GMT. Pressure 1020 mb was falling as frontal-wave low tracked SE across Liverpool Bay bringing a band of rain across Anglesey, North Wales and Cheshire. The day was damp with the rain easing and turning to heavy drizzle then to intermittent light drizzle. Cloud was thick all day so that it was the dullest since before the beginning of June. Daytime temperature only reached 14.9C falling to 12.4 overnight. {Bournemouth 24C, Isle of Wight 12.3h; Great Dunn Fell 11C; Port Ellen (Argyll and Bute) 14 mm} [Rain 2.4 mm; Max 15.7C; Min 12.0C; Grass 10.2C]
26th: Still overcast with low cloud hugging the mountaintops. At 09 GMT there was a little brightness breaking through, the temperature rising to 15.7C. But the wind was light NW'ly and, being close to the mountains, that direction does not bode well for cloud clearance here. The jet stream is still positioned NW-SE over the UK helping to generate the cloud cover. The day kept overcast and dry, it was brighter (x2) than yesterday so that the temperature rose to 17.2C. The night was overcast too. [Rain 0.3 mm; Max 17.2C; Min 12.4C; Grass 12.2C]
27th: Early fog and heavy drizzle from 06 GMT was lifting at 09 GMT. Pressure was 1020 mb but frontal cloud was still lying down the length of the UK. The morning was overcast and misty with visibility improving to moderate. It was calm or occasionally slight NE'ly wind. The afternoon continued overcast and very dull with fog developing towards midnight. [Rain trace; Max 18.5C; Min 14.2C; Grass 14.0C]
28th: Overnight the minimum was 14.5C, warmest of the month. Early morning fog and drizzle were clearing towards 09 GMT, but visibility was still very poor with some fine drizzle at times. Pressure was 1018 mb within slack gradients and it was calm. Low (994 mb) was well W of Ireland, but attendant fronts were tracking slowly towards us. With a lot of cloud still trapped in the relatively high-pressure the day was again thinly overcast, but warm with the temperature rising to 20.5C. In late afternoon it was brighter with even a glimpse of sunshine before turning cloudier again. [Rain trace; Max 20.5C; Min 14.5C; Grass 14.0C]
29th: An overcast but bright start to the day. Pressure was 1013 mb with high (1023 mb) S Scandinavia. Pressure gradients were very slack and there was little or no wind. Cloud was moderately high and thin and sometimes the veiled sun could be seen. It was very hazy with dust suspended in the atmosphere. On the 22nd there was dust was off the Strait of Gibraltar on its way N past Iberia and this might have reached here. Pressure 1013 mb was falling slowly; a band of fronts was over Ireland where it was already raining. Here the day was bright at first despite the cloud but this thickened in the afternoon with slight rain from 14 GMT. There was a deposition of light grey dust in the rain the source of which is under investigation. The temperature reached 21.4C, this moderate maximum was the highest of the rather cool month. [Rain trace; Max 21.4C; Min 14.1C; Grass 11.5C]
30th: A sunnier start today with cumulus clouds in the vicinity. High (1022 mb) was just to the SW and low (979 mb) between Greenland and Iceland had associated frontal cloud lying down the E of the UK where it remained cool with cloud and some rainfall. Cumulus stayed in the vicinity here most of the morning but began to clear in the afternoon. It was mostly sunny in the N and W of Anglesey the clouds near the mountains remaining over the weather station longer. [Rain 0.0 mm; Max 17.8C; Min 13.7C; Grass 13.4C]
31st: A fine morning with the least amount of cloud cover of 3 oktas recorded at 09 GMT during the month. It was the only day to see <5 oktas at this time. Pressure was 1022 mb in high (1023 mb) over the UK but there was a NE'ly breeze off the sea here and there was some cloud formation around noon due to convergent airflow. On the W coast the wind there too was off the sea but from the SW, the flow meeting in the middle of the island generated the cloud. As a result the temperature only reached 20.5C. [Rain 0.0 mm; Max 20.5C; Min 11.2C; Grass 8.2C]

August 2004

1st: A sunny morning with the temperature at 09 GMT 20.5C already exceeding yesterday's daytime maximum of 19.5C. Pressure was 1021 mb in ridge of high-pressure from Scandinavia. Low (988 mb) was SW Iceland with long frontal system W of Ireland. Sea fog in the North Sea was lapping the E coasts of Scotland and England. There had been a moderate deposition of light to dark grey dust overnight. Trajectory analysis using HYSPLIT indicated that the dust could have come from as far as Alaska and/or Canada, over 8000 km from Anglesey. There have been extensive wildfires in Alaska and Canada since mid-June with smoke blown out into the Atlantic S of Greenland. With patchy mostly thin cloud here around the day became very warm with a maximum of 26.4C during the afternoon. [Rain 0.2 mm; Max 26.4C; Min 11.8C; Grass 7.9C]
2nd: After a warm night with the minimum no lower than 17.4C, the highest of the month, it was 20.2C at 09 GMT. Pressure 1014 mb was falling as a thundery trough moved in from the SW. There were thunderstorms off the SW coast of Ireland, part of widespread activity through Europe, tracking NE. Ahead of this it was a fine morning with hazy sunshine through moderate to high mainly cirrus cloud. In an ESE'ly wind force 2/3 off the mountains the temperature rose steeply to 27.7C, the warmest day of the month and year. Relative humidity was down to 56% and this was the lowest seen in the month. By afternoon the cloud thickened and frequent thunder was heard from 1343 GMT for about an hour; there was light rain from 1355 GMT. There were some short heavier bursts of rain and more thunder as 3 storm centres moved across Anglesey from the Irish Sea. Sferics were recorded mainly to the N of here and no lightning was seen. During the rain there was a slight to moderate deposition of grey dust. The evening and night were overcast. [Rain 1.4 mm; Max 27.7C; Min 17.4C; Grass 14.1C]
3rd: A narrow band of slight rain passed over Anglesey between 02 and 03 GMT and there was a moderate deposition of dust. It was overcast, damp and very dull with little or no wind. There had been a further slight deposition of pinkish-grey dust. Overnight the minimum was 16.5C and had risen to 18.2C (dewpoint 17.7C) at 09 GMT. Pressure was 1012 mb and the wind was calm or very light S'ly. The morning kept dry but cloud thickened and became low with fine drizzle and light rain at times through the afternoon. It was the murkiest day with the lowest light intensity since before the beginning of June. During the evening thunderstorms that had developed over S Midlands, as low-level warm humid air from France met high-level cold air from the N, moved up the Welsh borders through Cheshire and N England. We did not have any thunder here but there was moderate rain from 2115 GMT, that turned heavy around 2330 GMT, lasting until 0400 GMT accumulating 19.0 mm. {Pershore (Worc.) 46.8 mm, Chalford (Surrey) 29C, Skegness (Lincs.) 8.4h}. [Rain 19.0 mm; Max 19.1C; Min 16.5C; Grass 15.5C]
4th: Low cloud and fog (100% relative humidity) by morning but the rain had stopped. Pressure was 1013 mb with a ridge of high-pressure (1018 mb) to the W indicating hope of at least a transient improvement. But frontal cloud was still lying through the UK just to the E of here. The morning remained foggy with drizzle or heavy drizzle at time. The afternoon was drier but kept misty until about 16 GMT when momentarily it lifted. Fog returned during the evening and was thick (visibility<100 m) either side of midnight. Tropical storm Alex was moving up the E coast of N America past Carolina. At the time the image was taken Alex was located approximately 400 miles east-northeast of Cape Hatteras, North Carolina and had maximum winds of 85 mph. [Rain 0.3 mm; Max 17.4C; Min 14.2C; Grass 14.2C]
5th: Early morning fog had lifted somewhat by 0900 GMT (visibility<1 km> and improved further later. Humidity values have been at or close to 100% for over 24h and evaporation has been zero. Pressure 1013 mb was unchanged with high (1027 mb) E Baltic and complex low (998 mb) W of Ireland. Frontal cloud remnants were still lying over the Irish Sea and more fronts were massed to the W; there was little or no change taking place. The morning was calm and misty but this cleared giving a mostly fine day over most of the eastern part of the island. Not here, it did brighten up around 1330 GMT and the temperature popped up to 23.4C before the low cloud and mist descended again. The evening and night were overcast and misty.. [Rain 0.4 mm; Max 23.4C; Min 12.9C; Grass 12.9C]
6th: Things were on the move again as the frontal cloud moved E and a following ridge of high-pressure stated moving across. As cumulus clouds formed there was some showery rain at 0500 GMT but by 09 GMT was bright and sunny with a brisk SW'ly wind. Pressure 1014 mb was rising with low (990 mb) S of Iceland. Ex-tropical storm Alex was now on the chart (<996 mb) S of Greenland tracking rapidly towards us. The morning was mostly cloudy with the afternoon sunnier and the sky was almost clear by evening. [Rain 0.0 mm; Max 22.2C; Min 14.0C; Grass 12.7C]
7th: The sky was almost clear to start the day with a little (SE'ly) or no wind. Pressure 1014 mb was almost unchanged with ex-tropical storm Alex deepening again (990 mb) to the SW. The day was mostly cloudy but there were some good sunny spells with the temperature rising to 22.4C. The evening and night were clearer at first before frontal cloud encroached by morning. [Rain 0.0 mm; Max 24.5C; Min 13.2C; Grass 11.5C]
8th: Ex-tropical storm Alex (975 mb) was just off SW Ireland at 06 GMT and associated frontal cloud could be seen to the SW. With pressure 1000 mb falling and in a tropical-type S'ly airflow it was a sunny and very warm morning. The temperature rose to 24.5C by 0900 GMT (59% relative humidity; dewpoint 15.9C. Soon the frontal cloud moved over with a band of rain lying to the SW. There was showery rain at 14 and 19 GMT, as the rain band was broken up by the Snowdonia Mountains, then moderate rain from 02 GMT with a heavy burst about 05 GMT. [Rain 7.9 mm; Max 24.7C; Min 16.7C; Grass 12.8C]
9th: Overcast with light rain at times up to 09 GMT. Pressure 1004 mb was rising again as the mature Alex (997 mb) tracked slowly N off Ireland. Frontal cloud was still lying down the W and did not properly clear through the day, tending to thin and break only to reform again later. A frontal wave low started to form over Anglesey. There were some brighter spells, with a little sunshine, at times and it was clearer towards evening, but soon was cloudier. [Rain 0.2 mm; Max 22.6C; Min 15.0C; Grass 14.8C]
10th: Overcast with little (NE'ly) of no wind. Low (990 mb) former Alex was still to the W but seemed to have deepened. Associated frontal cloud was still persistent over the UK with frontal low bulge (1007 mb) now centred over Birmingham. We were within this as pressure here was also 1007 mb. The morning kept dull with a few spots of rain at 0915 GMT but then cleared up to give a sunny afternoon and evening. The front remained almost stationary over N England {Buxton 68 mm} and SW Scotland where the rain continued to accumulate. Over 72 h, to 06 GMT today, Eskdalemuir had 117 mm and Leuchars 57 mm while to the N it was sunny and dry with the highest temperature of the day 27C in the highlands. North Wales escaped with even Capel Curig recording only 10 mm. {Buxton 68 mm, Aultbea (Highland) 27C, Lerwick 12.8h sunshine}. [Rain trace; Max 23.8C; Min 15.3C; Grass 14.4C]
11th: After a clear night with moderate cooling (grass minimum 10.8C and still humid air) heavy dew formed on the grass (0.31 mm) but it was cloudier by morning. Pressure was 1008 mb with frontal cloud still lying to the NE. The morning was bright, but with minimal sunshine, and a light ENE'ly wind. There was some sunshine at first in the afternoon when the temperature rose to 24.1C but towering cumulus clouds soon developed. Later cumulonimbus were observed. There was a moderate shower at 1525 GMT and thunder was heard at 1603 GMT. Further thunder was hear from 1702 GMT lasting about 30 minutes. There were further light showers later. It was wet in Scotland with flooding reported in Perthshire and Dundee. A mudslide on the A9 near Dunkeld engulfed a car in mud. The family of 5 fortunately escaped uninjured. {Leuchars, Scotland 58 mm}[Rain 6.3; Max 24.1C; Min 14.0C; Grass 10.8C]
12th: At 06 GMT low (998 mb) was near Lands End and there was a frontal trough over North Wales. At 08 GMT the sky was still looking ugly and threatening after early showers of rain. By 09 GMT the sky rapidly cleared overhead leaving cumulus, and cumulonimbus, over the Snowdonia Mountains and to the SW. Pressure 1001 mb was rising with frontal cloud cleared to the NE and it was a sunny morning. But by noon convective clouds built up rapidly. With cumulonimbus clouds in the vicinity there was thunder from 1430 GMT and a heavy rain shower from 1515 to 1530 GMT. Storms were drifting NW across Anglesey from the mountains, one storm passed to the NE with several flashes of lightning. But the most active storm was to the W and centre of the island where there was frequent thunder and lightning and heavy rain that caused local flash flooding. The road from Malltraeth to Bethel was flooded in 2 places and only just passable. The storms had died out by 18 GMT leaving a mostly cloudy evening and night. [Rain 4.7 mm; Max 22.7C; Min 14.5C; Grass 12.1C]
13th: A cloudy but bright start with low cloud and mist on the lower slopes of the Snowdonia Mountains. Pressure 1006 mb was rising a little but complex low-pressure remains over the UK with frontal systems lying just to the N. Pressure was high (1021 mb) over Spain and North Africa but low over the Mediterranean Sea. The morning was overcast and there was fog hanging around coastal parts on the W of the island. After a slight shower the afternoon was brighter with a little sunshine. Convective cloud developed again to the S, but no precipitation was observed. After a clearer evening it was cloudier later. [Rain 0.2 mm; Max 19.8C; Min 13.2C; Grass 10.5C]
14th: A bright morning with a lot of blue sky and sunshine with any cloud overhead dispersing towards 09 GMT. Pressure 1016 mb was rising but it was soon cloudier again with remnant frontal cloud encroaching once more. During the day there was patchy cloud from time to time but also some sunny spells. A warm day with the temperature rising to 23.1C but it was still humid, around 90%. A clear evening but cloudier later. Wasps continue to be a problem out of doors and they get into the house if doors or windows are left open for only a few minutes. [Rain 0.3 mm; Max 23.1C; Min 14.0C; Grass 12.4C]
15th: Slight showers of rain around 01 GMT then it was brightening up towards 09 GMT. Pressure was little changed with the complex low-pressure system to the W. A bright morning with cumulus clouds developing after a brief clearer spell. But it was fresher (18.7C; RH 82%) with a moderate SSW'ly breeze. Some spots of rain during the afternoon under persistent orographic wave clouds parallel with the mountains. Elsewhere on the island it was mainly sunny. During the evening a frontal trough moved up through Wales with some heavy rain. Here it was from 2130 GMT becoming heavy (10 mm in an hour) around 2315 GMT then turning showery after 01 GMT. [Rain 15.4 mm; Max 21.0C; Min 15.3C; Grass 13.0C]
16th: A blustery start to the day with a force 5 SW'ly wind. Pressure 1004 mb had fallen with twin lows (998 mb) to the W of Ireland. The morning was cloudy but the cloud cleared to give a mostly sunny afternoon. More cloud encroached during the evening and it turned showery later. The village of Boscastle in Cornwall was devastated during the afternoon following torrential rain. Over 50 mm of rain was reported to have fallen in 2 hours and 133 mm in 7 h in the area was reported by the Environment Agency. As more reports came in in succeeding days falls could have been heavier as 202 mm over 24-h was reported at nearby Otterham. With upland areas saturated with water from recent heavy rains there was an immediate runoff. This caused flash flood water to race down 3 rivers to join and pass through the village up to 10 ft deep. The village is situated in a steeply sided valley (called a coomb locally). Many vehicles and trees were washed away and people had to be rescued from trees and buildings by 6 helicopters that were dispatched to the scene. There was a lot of property damaged but amazingly no reports of loss-of-life. {Slaughterbridge (Cornwall) 75 mm; Southport 10.5h} [Rain 4.4 mm; Max 20.3C; Min 14.7C; Grass 13.8C]
17th: Early showers with a heavy one just before 07 GMT were clearing as 09 GMT approached. Pressure was 998 mb within disturbed low-pressure encompassing the UK, Ireland, most of N Europe, and Scandinavia. The only high-pressure I could see on the 06 GMT chart was over Russia (1021 mb), and moderately-high (1016 mb) over Greenland and (1013 mb) N Africa. The morning was bright with some sunny spells although cumulus clouds remained in the vicinity. The afternoon was mostly sunny, any showers keeping away, but became overcast by evening.. Cornwall was again affected by rain during the afternoon and this moved N into South Wales later. [Rain 9.2 mm; Max 21.6C; Min 12.9C; Grass 10.2C]
18th: With the sky looking black and threatening and the SSW'ly wind reaching strong to gale-force the squalls arrived at 0640 GMT. In gusts of wind approaching 50 mph the facing windows were peppered with beechnuts torn from a nearby beach tree. The most violent was at 0730 GMT when garden furniture was scattered. Garden plant suffered with previously fine upstanding purple sprouting cabbages flattened on the vegetable plot, the row of runner beans sticks were leaning to the NE, and twigs and leaves were torn from trees littered the lawns and roads. Rain was heavy with up to 6 mm accumulating. Pressure fell to 986 mb with 1 of twin lows over Anglesey and a 'comma' of heavy rain across the Irish Sea and over NE Ireland. The other low (983 mb) is still lying to the SW. After the rain the morning turned bright and sunny as the cloud cleared away. By afternoon convective clouds returned and lightning was seen under a cumulonimbus to the SW at 1400 GMT and thunder heard at 1414 GMT following a sharp shower with another cumulonimbus closeby to the S. Thunderstorms were widespread in the UK and Europe and were reported as severe in Merseyside and Cheshire during the afternoon. Showers continued into the evening but ceased just before midnight. With continued heavy rain on already saturated soils there were more mudslides in Scotland on the A85 between Lochearnhead and Lix Toll, N of Callander. These trapped 30 vehicles and a Belgium tourist coach. People had to abandon their vehicles and were rescued by helicopters. {Camborne (Cornwall) 63.3 mm; Ross-on-Wye (Herefordshire) 8.5h; Marham (Norfolk) 24C} [Rain 7.3 mm; Max 19.8C; Min 14.4C; Grass 13.7C]
19th: A blustery morning with a strong SW'ly breeze (f6). Pressure was 994 mb within complex low-pressure (990 mb) over the UK. There was a rain area over N England and N Ireland. Overcast here with ragged low clouds and mist on the lower slopes of the Snowdonia Mountains. The day kept overcast and windy and there was intermittent light to moderate rain from 17 GMT through the night. [Rain 11.3 mm; Max 18.5C; Min 14.2C; Grass 13.2C]
20th: Grey and misty with the wind veered N'ly and it was still raining. Pressure (1002 mb) had risen with the low-pressure (985 mb) moved to the Norwegian Sea. A ridge of high-pressure was to the SW but another low (1003 mb) S of Greenland was again heading our way with the jetstream lying well to the S. The temperature was 13.5C and was the maximum for the next 24-h, and lowest of the month, as cooler air flowed in from the N. The morning was wet with very poor visibility the rain not easing until after 13 GMT. After a shower just before 17 GMT the evening brightened and there was a little sunshine that led on to a clear night. [Rain 9.6 mm; Max 13.5C; Min 13.3C; Grass 13.3C]
21st: A cool clear night with air minimum of 7.7C, lowest of the month, and 5.4C on the grass. But it was cloudier by 09 GMT with cumulus clouds developing. Showers were reported during the morning on the W coast at Malltraeth and Four Crosses. Pressure was 1017 mb with a ridge of high-pressure moving across from the W. There were sunny spells in the morning these lengthening in the afternoon. By 18 GMT thin cloud had encroached but it kept dry during the evening and night. The cereal harvest has been ripe in the fields around Llansadwrn since before the end of July. The wet weather (nearly 100 mm this month so far) has seen combine harvesters abandoned in waterlogged fields unable to continue work with grain quality now quickly deteriorating. In recent years harvests would have been safely under cover by now. [Rain mm; Max C; Min 7.7C; Grass 5.4C]
22nd: An overcast and calm morning with some spots of rain at 1045 GMT. Pressure was unchanged at 1017 mb but was now falling as low (998 mb) approached from the SW. Associated fronts brought patchy slight rain here, in the lee of the Snowdonia Mountains where there were light S/SE'ly winds, with some bright sunny spells. But heavier rainfall arrived from 2100 GMT with moderate to heavy bursts through the night. [Rain 20.3 mm; Max 18.6C; Min 9.6C; Grass 7.5C]
23rd: Moderate rain led up to 09 GMT before ceasing. Pressure was low (1001 mb) over SW Ireland and here a little higher at 1005 mb. The slow-moving frontal cloud that had given the rain was still in the vicinity. There was a little blue sky approaching but generally the sky kept overcast during the morning. The afternoon was brighter particularly in the west of the island with some warmer sunny spells. After some sunshine in the evening cloud it became cloudy again with a moderate shower around 23 GMT. [Rain 4.0 mm; Max 20.2C; Min 13.0C; Grass 12.3C]
24th: Early light showers of rain under low ragged clouds and, being misty, visibility was only moderate. Pressure was 1003 mb within a low-pressure system over the UK. The morning was dull with a little rain from time to time while the afternoon saw a few glimpses of the sun. The evening and night were overcast. [Rain 1.0 mm; Max 18.4C; Min 13.7C; Grass 11.6C]
25th: Some showery rain between 04 and 05 GMT and still overcast with low ragged clouds at 09 GMT. Pressure was 1007 mb with low (1000 mb) over the North Sea and high (1033 mb) was in mid-Atlantic to the SW. By noon it was a little brighter and again there were some brief sunny spells in the afternoon. By evening cloud had encroached once more. [Rain trace; Max 18.7C; Min 13.2C; Grass 11.8C]
26th: Low cloud mist and slight drizzle around 09 GMT. Deepening low (1001 mb) was W of Scotland while pressure here had risen to 1019 mb. By noon the low was (994 mb) and thick frontal cloud and rain over Scotland, heavy around Fort William in the afternoon. The morning here was dull at first but brightened by noon with a few sunny spells early in the afternoon. By mid-afternoon cloud on a warm front had encroached from the NW and the wind had backed SW'ly and strengthened, but it was still dry. At 18 GMT the low had deepened to (988 mb), was just off Cape Wrath, and the wind here was force 6/7. There was rain from 2030 GMT becoming heavy rain at 2145 GMT before easing around midnight. The low was (983 mb) just S of the Faeroe Islands. [Rain 12.9 mm; Max 18.7C; Min 13.0C; Grass 10.9C]
27th : A few slight showers in the early hours then before 09 GMT the sky started to clear as the cold front moved S. Altocumulus clouds overhead were thinning leaving some stratocumulus over the mountains of Snowdonia. Pressure was 1008 mb with the vigorous low (981 mb) approaching Shetland, while pressure was high (1027 mb) to the SW over the Azores. Another new low was forming S of Greenland. The day became sunny and dry over Anglesey with some fair-weather cumulus clouds; a line of stratocumulus persisted over Snowdonia and thickened late in the afternoon spreading to Anglesey by 18 GMT. The night became overcast. [Rain 0.0 mm; Max 19.4C; Min 13.8C; Grass 13.5C]
28th: Overcast at first but there was a patch of blue sky, enough to patch a sailor's trousers, lying to the W by 09 GMT. Pressure was 1012 mb with yesterday's low (984 mb) in the E Norwegian Sea but the new low (987 mb) was tracking E just SW of Iceland. The patch of blue sky enlarged and the sky seemed to be clearing, but this was not to be; the day was disappointingly mostly cloudy and cooler than of late (max 17.2C) but again was dry until nightfall. [Rain 0.9 mm; Max 17.2C; Min 10.0C; Grass 7.7C]
29th: Overcast and dull with the blustery SW'ly wind strengthening to force 6 by 09 GMT. Pressure 1006 mb was falling as low (986 mb) approached Cape Wrath. A cold front on a line through Fort William was producing some heavy rain across Scotland. Light drizzly rain soon started here, with the visibility deteriorating to very poor under low stratiform cloud. With yet another low W of S Greenland (984 mb) on it's way the unsettled 'autumnal' weather was set to continue with no chance of completing the cereal harvests. The sky cleared during the morning and the afternoon was sunny before it turned showery these lasting into the evening. The night was partly cloudy. [Rain 1.0 mm; Max 18.5C; Min 12.1C; Grass 10.8C]
30th: Pressure 1014 mb was rising as a ridge of high-pressure moved across from the W. But the day was one of sunshine and threatening showers, although there was only one at 1430 GMT that passed over over the weather station. By nightfall the sky was clearing and it was a clear night with a bright full moon. [Rain trace; Max 17.5C; Min 12.2C; Grass 10.0C]
31st: Overnight the grass minimum fell to 4.8C, lowest of the month and lowest since 28 June (4.5C), and there was heavy dew. Almost clear sky at dawn but became cloudier before 09 GMT. Pressure 1020 mb had risen in the ridge of high-pressure (1022 mb) off Lands End. Pressure was low (1001 mb) near Oslo while low (978 mb) was lying just off the S tip of Greenland on track eastward. The morning was bright with sunshine between cumulus clouds in a light NNW'ly breeze. [Rain 0.0 mm; Max 18.3C; Min 8.3C; Grass 4.8C]

September 2004

1st: A sunny start under an almost clear sky. Pressure was 1016 mb under the influence of high-pressure (1019 mb) lying to the SE. It was a mostly sunny day with abundant fair-weather cumulus clouds developing by the afternoon. The air was very clear late in the afternoon affording fine views across the Menai Strait towards the Snowdonia Mountains. The sky cleared by evening. [Rain 0.0 mm; Max 20.0C; Min 9.3C; Grass 5.5C]
2nd: Frontal cloud encroached from the W during the night and was lying over the Irish Sea by morning. Pressure was 1015 mb with slack gradients over the UK. During the morning the cloud thickened and there was occasional slight drizzle. By afternoon there was partial clearance with orographic waves clouds developed to the S in the lee of the mountains. The night was mostly cloudy. [Rain trace; Max 18.3C; Min 11.3C; Grass 7.8C]
3rd: An almost overcast morning with a strengthening S'ly breeze. Pressure was 1019 mb with tightening isobars as low (990 mb) approached the W of Scotland. With a moderate S'ly in the afternoon a clear slot developed to the SE in the lee of the mountains where several lenticular orographic wave clouds persisted over the Menai Strait. The evening was overcast and dull. [Rain 0.4 mm; Max 18.0C; Min 12.2C; Grass 9.7C]
4th: Overnight the air minimum was 15.0C, warmest of the month. With thickening and lowering cloudbase there was drizzle, heavy for a time, from 06 GMT. By 09 GMT 0.4 mm had accumulated. Visibility was very poor in mist and low cloud with near 100% relative humidity. Pressure 1025 mb, however, had risen with high pressure building to the S. Lows around Iceland had associated slow-moving fronts over the UK. Misty with slight drizzle at times in the morning, became bright during the afternoon with occasional glimpses of sunshine. Towards evening the sky gradually cleared. [Rain 0.1 mm; Max 19.5C; Min 15.0C; Grass 14.8C]
5th: Clear sky at night until past 02 GMT then fog rolled in becoming dense (visibility <100 m) by 06 GMT. This lifted over about 20 minutes from 07 GMT and by 09 GMT visibility was moderate. Pressure was 1028 mb with high (1032 mb) to the SE over Europe. But frontal cloud was lying to the NW over N Ireland and Scotland. With mist continuing to clear the morning became mostly sunny, and pleasantly warm. The afternoon was mostly sunny too with a light NE'ly breeze. The evening was hazy then sea fog rolled along the Menai Strait from the SW entrance at 1830 GMT and affected here for a while then retreated. [Rain trace; Max C; Min 14.3C; Grass 11.3C]
6th: Misty after midnight and fog (visibility <200 m) at 06 GMT. By 08 GMT it had lifted and cumulus clouds were forming. At 09 GMT the sun was breaking through although it remained foggy around the coast until later. Condensation of fog on tree leaves had been heavy and they were dripping as if after rain. It was a good morning to look at hundreds of cobwebs around the garden made easily visible with droplets of fog. Pressure was 1029 mb with a high (1036 mb) developed over Scotland intensifying to (1038 mb) by noon. A weak frontal system was lying across the UK just to the N of here. The day was mostly sunny with haze thickening, the light NE'ly breeze became fresh to strong during the afternoon. [Rain 0.0 mm; Max 21.8C; Min 14.5C; Grass 12.9C]
7th: A cloudless sunny start to the day. Pressure was 1034 mb within high (1039 mb) centred just off the E coast of Scotland. Hazy (with smoke pollution) sunshine continued all day with a moderate to fresh at times ENE'ly wind. After a peach coloured evening sky it was a clear night. The spell of drier weather has enabled most of the cereal crop to be harvested across the UK. Yields are reported to be higher than last year, but much of it is said to be of poor quality and fit only for stock feed. As a result there could be a shortage of home produced quality wheat for bread-making flour. Quality of grain in France and Europe is said to be generally good this year. [Rain 0.0 mm; Max 19.5C; Min 12.7C; Grass 11.4C]
8th: Another day with clear sky and it was less hazy today. Pressure was 1033 mb and there was a light SE'ly breeze. The temperature rose to 24.6C, the highest of the month. [Rain 0.0 mm; Max 24.6C; Min 12.2C; Grass 9.8C]
9th: For the 3rd day clear blue sky and sunshine continued. Pressure was 1025 mb with high (1036 mb) over the Netherlands moving E and declining, and (1025 mb) S France. There was a light ENE'ly wind and the temperature rose to 24.5C, just 0.1C short of yesterday's maximum. By nightfall some scattered clouds appeared. [Rain 2.0 mm; Max 24.5C; Min 10.1C; Grass 7.0C]
10th: At 06 GMT the sky was clear but soon was cloudier with light rain, and very poor visibility, that turned moderate during the morning. There was a shallow low (1002 mb) on a frontal wave SW of Ireland tracking N and deepening. At 09 GMT pressure was 1010 mb was falling, there was little or no wind at first but was S'ly later. A light reddish-brown Saharan dust (Munsell colour chart 2.5YR 7.5/4) was being deposited in the rain. Dust was forecast to pass over the UK by the University of Athens' SKIRON dust model. Dust storms have been occurring over North Africa during recent weeks. Trajectory analysis using the HYSPLIT numerical model on the NOAA ARL website confirmed a Saharan origin for this dust. The most likely source was just inside the SW corner of Algeria, near the border with Spanish Sahara and Mauritania, between 12 GMT on the 5th and 00 GMT on the 6th September. By afternoon there was low cloud and mist, but this cleared later. By evening there were breaks in the cloud and respite from 18 until 23 GMT when there was a further spell of light to moderate rain that turned to drizzle by 03 GMT. This the first of 3 wet days accumulated 15.0 mm over 7.5 h duration. [Rain 15.0 mm; Max 17.0C; Min 14.0C; Grass 10.8C]
11th: At midnight the low was (989 mb) tracking N off the W coast of Ireland with an associated cold front over the Irish Sea where winds were strengthening. At 09 GMT with pressure on 1005 mb the SW'ly was force 6. Around the coasts and Llyn it was up to force 7 with gusts of 40 mph. There had been a further deposition of Saharan dust during the past 24-h, of darker colour it was likely to have been mixed with other dust since wet deposition following 09 GMT yesterday. There was slight rain in the morning from 0920 GMT. There was a spell of about an hour of heavy rain around 15 GMT turning lighter later before ceasing during the evening when the sky started to clear. At midnight the low was (984 mb) just N of Scotland and there was a weak ridge of higher pressure to the W of Ireland ahead of another low (983 mb) in the Atlantic to the W. This the second of 3 wet days had 24.4 mm rainfall over 8.0 h, a total of 39.4 mm. [Rain 24.4 mm; Max 15.5C; Min 13.2C; Grass 12.2C]
12th: By morning in the strong SW'ly wind cloud cover was increasing. At 09 GMT pressure was 1008 mb and falling as the Atlantic-low S of Iceland deepening to (973 mb). Fronts to the W approached quickly and there was rain from about 15 GMT. This became moderate to heavy with strong to gale force 8 SW'ly wind during the evening and night until after midnight. It was windy around all Irish Sea coasts with a peak gusts of 55 mph reported at Valley and 54 mph in the Isle of Man. In over 12.7 h of continuous rain 30.0 mm of rain accumulated in this the third wet day. Over the 3 days 69.4 mm had accumulated. Rainfall totals for selected stations are shown in the graphic. Capel Curig in the Snowdonia Mountains received over 109 mm in the 72-h period up to 06 GMT on the 13th. [Rain 30.0 mm; Max 15.0C; Min 9.0C; Grass 7.5C]
13th: The gale force 8 SW'ly wind had moderated and veered NW'ly by morning but was still fresh (f5). The sky was clearing and by 09 GMT was just 2 oktas with pressure 997 mb and still falling. Low (974 mb) was to the NW with closely packed isobars. Irish Sea coasts continued to have strong winds with up to 50 mph gusts reported. The clearance was deceptive as we were in a very showery airflow with troughs to the W. The next 24-h was to consist of frequent blustery showers with the wind rising to force 6/7 at times. A shower of small hail was reported (thanks to Ellen) in Menai Bridge around 1215 GMT. There were at least 16 showers that could be identified on the autographic rainfall chart lasting about 2.2h overall and accumulating 8.3 mm. [Rain 8.3 mm; Max 14.0C; Min 9.9C; Grass 8.4C]
14th: At midnight twin lows (980 mb) were over N Ireland tracking E, and W of Shetland. Showers, many blustery, were most frequent between midnight and 06 GMT, but they continued well into the afternoon. Pressure was lowest 986 mb between 04 and 06 GMT and by 09 GMT had risen to 993 mb with the twin lows (989 mb) over N England and Scotland. By evening the sky began to clear and the wind moderated. [Rain 0.8 mm; Max 15.0C; Min 10.0C; Grass 8.5C]
15th: Overnight the air temperature fell to 7.4C, coolest of the month, and to 5.0C above the grass. It was bright and sunny after recent showers but was still mostly cloud covered by 09 GMT. Pressure had risen to 1019 mb as a ridge of high-pressure extended across from high (1031 mb) W of the Iberian Peninsular. But a large complex of low-pressure (985 mb) was in the Atlantic W of Scotland with a slow-moving warm front approaching Ireland. The day was sunny with light winds with the sky mostly clearing by the afternoon. [Rain 0.0 mm; Max 18.0C; Min 7.4C; Grass 5.0C]
16th: With clear spells and little or no wind overnight there was dew on the grass (minimum 5.9C) at dawn but was becoming cloudier. By 09 GMT it was overcast with fine drizzle beginning within 20 minutes. It was also windier with the S'ly wind reaching force 5 as pressure 1017 mb was falling. Low (961 mb) was anchored SW of Iceland, an associated warm front was lying over Scotland and the west coast of Wales with a cold front W of Ireland.. Isobars were tightening and the gusty wind strengthened through the day, reaching strong to gale force 8 at times during the afternoon and evening. The rain that had been intermittent and light through the day became moderate in the evening and night. [Rain 12.5 mm; Max 15.2C; Min 8.8C; Grass 5.9C]
17th: At midnight with the low deepened to (957 mb) it's associated cold front was lying across from Newcastle to Anglesey. The rained eased and the wind moderated as breaks appeared in the cloud. At 09 GMT pressure was steady on 1013 mb but there was a developing Atlantic-low (990 mb) to the W tracked towards Scotland during the day. The day was bright and it kept dry, but towards evening thicker frontal cloud encroached. This brought 7.4 h of moderate to heavy rain after midnight accumulating 22.0 mm by morning. [Rain 22.0 mm; Max 17.9C; Min 12.0C; Grass 11.2C]
18th: After the rain the sky was clearing rapidly at 09 GMT with the cold front moving away SE. Pressure 1004 mb was rising as a NW'ly airflow was introduced. The morning was bright with good sunny spells. The afternoon was cloudier with a little drizzle at 1320 GMT. The edge of a showery trough in the NW brought a short moderate shower at 1720 GMT when a rainbow was sighted. The evening and night were manly cloudy but kept dry. The total rainfall here in the 48-h 18 GMT on the 16th to 18 GMT on the 18th was 34.0 mm. Again this was one of the heaviest falls in coastal areas around the Irish Sea. It exceeded Keswick (Cumbria) with 29 mm but was lower than Capel Curig with 48 mm and Eskdalemuir in Scotland. [Rain 0.2 mm; Max 16.2C; Min 12.4C; Grass 12.0C]
19th: A bright start to the day with a fresh SW'ly wind that made the 12.5C temperature feel cool. Pressure 1014 mb was rising; Azores-high (1027 mb) was just too far S and with low (971 mb) in the Norwegian Sea, and (980 mb) SE Greenland tracking rapidly E, the weather would remain unsettled. The day was mostly sunny but frontal cloud encroached by evening. The SW'ly wind freshened reaching near-gale to gale force 8 at times. Winds were particularly strong again around Irish Sea coasts with gusts reported up to 53 mph at Valley. There were 5.5 h of moderate rain from 2100 GMT that accumulated 15.9 mm. [Rain 15.9 mm; Max 15.1C; Min 9.6C; Grass 6.7C]
20th: With deep complex low-pressure (968 mb) over the Norwegian Sea the strong winds backed W'ly by morning. Pressure 1003 mb was rising but we were in a showery airflow with short showers at 09 and 0920 GMT. The morning kept overcast but there were some sunny spells in the afternoon although there was a moderate shower at 1500 GMT. The evening and night became very windy again reaching gale force 8 with strong gusts. Once more Irish Sea coastal stations reported gusts in excess of 50 mph while Blackpool reported 53 mph and Shannon 57 mph. [Rain 0.9 mm; Max 14.8C; Min 12.2C; Grass 11.2C]
21st: It was bright with a little sunshine early but by 09 GMT it was cloudier. There was a moderate to strong NW'ly wind but pressure 1018 mb was rising. Azores-high (1031 mb) had a ridge extended northwards into the Atlantic. But there were fronts to the N of it, associated with deep low-pressure (985 mb) off Newfoundland, that would bring rain tomorrow. The morning was mainly dull and cool with the maximum temperature reaching only 13.5C, the coolest of the month. By afternoon there were some sunny spells and it kept dry until after midnight. [Rain 5.4 mm; Max 13.5C; Min 9.7C; Grass 7.4C]
22nd: There was rain from 05 GMT as frontal cloud moved across from Ireland, it was still overcast and raining at 09 GMT. Pressure was 1016 mb and rising with high (1035 mb) lying to the SW. With frontal cloud nearby the morning continued overcast with the rain dying away. There was a further spell of light rain in the afternoon, but it was less windy. The evening and night saw more rain, in all of 7.3 h duration but only 8.5 mm accumulated. [Rain 8.5 mm; Max 16.0C; Min 10.8C; Grass 7.2C]
23rd: With frontal cloud still lying across the UK the day started dull but after some showery rain the morning kept dry. Pressure was 1014 mb with ridge of high-pressure (Iceland to Azores) to the W and low (980 mb) over N Scandinavia. This was giving a cool N'ly airflow encompassing the UK and moving into France, around a weak low N of Italy, reaching the coast of the South of France at Ramatuelle by evening. After a maximum of 26.4C the temperature cooled to 16.7C but during the night (0145 GMT) there was a strong gusty Föhn wind, the Mistral, off the mountains to the N with the temperature rising to 22.9C. The afternoon here was bright, with a maximum of 14.9C, and the evening and night clear and colder (minimum 8.8C). [Rain trace; Max 14.9C; Min 13.6C; Grass 11.9C]
24th: Another bright start to the day with cumulus clouds blowing along on a light NE'ly breeze. In the clear air visibility was very good. Pressure at 09 GMT was 1023 mb within high pressure (1030 mb) to the SW. Low (975 mb) was tracking E between S Greenland and Iceland. Ex-hurricane Karl was tracking N in mid-Atlantic well S of Greenland. The day was bright and sunny with a temperature of 11.1C, and 69% relative humidity that was lowest of the month, rising to 15.1C around noon. The afternoon and night were clear with little or no wind. In the South of France the Mistral was still strong with a temperature of 22.3C and 50% relative humidity at 0630 GMT. By 1300 GMT the temperature had risen to 27.4C and the relative humidity had fallen to a remarkably low 8%. The wind strength was force 5/6 rising to force 6/7 at 1530 GMT but the temperature began to fall away and was 23.3C. By 2200 GMT the wind moderated. [Rain 0.8 mm; Max 15.1C; Min 8.8C; Grass 5.9C]
25th: The temperature on the grass fell to 4.9C, lowest of the month before frontal cloud encroached after midnight. This was associated with the Atlantic-lows that were approaching NW Ireland. At 09 GMT pressure 1022 mb was falling but pressure was still high (1030 mb) off SW Ireland. Frontal cloud was lying over the Irish sea with a triple point over S Scotland. It was overcast with low cloud and drizzle, heavy at times, on a freshening W'ly wind. Visibility was very poor improving a bit at first in the afternoon, but deteriorating again in further mist and drizzle during the evening and night that was mild. [Rain 0.3 mm; Max 16.2C; Min 8.1C; Grass 4.9C]
26th: There was little change by morning, damp, overcast and misty with poor visibility. Pressure 1023 mb, however, was rising again with the high (1029 mb) little changed to the SW of Ireland. With the warm front passed to the E there was some respite in the afternoon and evening that had some short bright spells. Further frontal cloud from the NW brought a return of mist and light drizzle during the again mild night. [Rain 3.3 mm; Max 15.8C; Min 12.8C; Grass 11.2C]
27th: At midnight the low (980 mb) to the N had moved over the Norwegian Sea. Low stratiform cloud was slow-moving over Anglesey with frontal clod stretching from the Baltic to N France. There was further frontal cloud to the NW associated with another low (1010 mb) S of Iceland. Pressure was steady on 1022 mb and there was little or no wind. There was little change during the morning that was damp with some drizzle; the afternoon no better keeping overcast and dull under the cloud. [Rain 0.4 mm; Max 15.8C; Min 13.4C; Grass 13.5C]
28th: Still no change. Overcast, dull and constant drizzle or light rain during the morning, By afternoon the rain stopped and although overcast and sunless here one or two sunny intervals were reported in Benllech! [Rain 1.7 mm; Max 14.5C; Min 14.0C; Grass 11.2C]
29th: More of the same, overcast with fine drizzle at time through the day. Pressure on 1016 mb was unchanged and the was little of no wind. Pressure was high (1022 mb) N France and a warm front was lying N Ireland through Anglesey to Southampton. By evening there was some movement in the fronts. The warm front moved E and was replaced with a cold front moving across the Irish Sea. This brought 7.1 h of moderate rain from 2300 GMT, the 12.9 mm bringing the total for the month up to 165.9 mm the wettest September since 1999. [Rain 12.9 mm; Max 15.8C; Min 9.9C; Grass 5.0C]
30th: The day began overcast with frontal cloud, but it was thinning and decreasing leading to some hazy sunshine during the morning. Pressure was 1015 mb and rising slowly and winds were light. The afternoon saw some sunny spells with the sky cleared by dusk. The night was clear at first, with little or no wind, and was lit by the just waning moon. But it was cloudy again before morning. [Rain trace; Max 15.9C; Min 12.4C; Grass 12.2C]

October 2004

1st: A bright but breezy start to the month. At 09 GMT there were breaks in the cloud (6/8) but pressure 1013 mb was falling with low (978 mb) S of Iceland. Frontal cloud was lying over the W of Ireland with winds strengthening in the NW. The wind, a Sly force 5, strengthened during the morning . After a brief sunny spell in the afternoon it became cloudier with moderate rain from 1315 to 1500 GMT before turning showery. The night was clearer but winds remained strong. [Rain 4.6 mm; Max 13.8C; Min 8.2C; Grass 4.0C]
2nd: After a slight shower at 0515 GMT, the morning was cloudy at first with occluded frontal cloud over the Irish Sea. Pressure 1008 mb continued to fall with the slow-moving low (976 mb) still S of Iceland. It was still windy with the SW'ly force 6 only moderating later in the day. Irish Sea coasts again experiencing the strongest winds with gusts up to 45 mph. But the day became bright and sunny with cloud breaking up. There was a slight shower at 1830 GMT then the night became clear with the wind lessening. [Rain trace; Max 15.0C; Min 9.2C; Grass 4.9C]
3rd: A bright morning with broken clouds and a moderate S'ly breeze. Pressure 1011 mb was falling and by afternoon it was cloudier with frontal cloud moving across from the W. There was moderate to heavy spells of rain from 1430 GMT through until 07 GMT the next day accumulating 25.1 mm. {Capel Curig 40.6 mm}. [Rain 25.1 mm; Max 15.6C; Min 9.0C; Grass 4.3C]
4th: It was wet underfoot after the overnight rain and there was a small pool of water standing on the 'old cricket field' next to the weather station. But the sky had cleared rapidly and was 3 oktas at 09 GMT. Pressure was 1001 mb, with complex low-pressure to the N, and the strongest winds transferred to the North Sea. The wind was W'ly force 5 here with small cumulus cloud being blown rapidly across Anglesey. Over the mountains of Snowdonia the clouds were more developed giving some showers. With temperatures on the summits around 2C it was possible that the showers were wintry. The day was dry with some good sunny spells but there were frequent showers (about 12 were identified on the autographic rainfall recorder) in the night from 20 GMT. During the evening the SW'ly wind and reached gale-force 8. At RAF Valley a maximum gust of 54 mph was recorded. There was a spell of moderate rain from 04 to 07 GMT. Another 15.4 mm that brought the total this year to 899 mm. {Capel Curig 49 mm}. [Rain 15.4 mm; Max 13.5C; Min 8.1C; Grass 6.6C]
5th: At 06 GMT low (971 mb) was N of Scotland with showery troughs across Wales and N Ireland. Before 09 GMT there were squally showers and pressure was 1000 mb. There was a fresh (f6) SW'ly wind and there were fast-moving cumulus clouds in the vicinity. Around the low strong N'ly winds caused a duststorm off Iceland. Plumes of light-brown dust (possibly soil and/ or eroded peat containing fine particles of volcanic ash) were being blown off the entire south coast of the island into the Atlantic Ocean (see satellite images). Trajectory analysis, using the HYSPLIT model at the NOAA Air resources Laboratory Website, shows that some dust was transported directly to Anglesey arriving tomorrow (the 6th) while some traversed S around Ireland and got caught up in the slow-moving low over the Bay of Biscay on the 9th and 10th to bring a further deposition on the 12th. The morning brightened with just a few slight showers before noon when it was blustery with the wind force 7/8 at times. After a clearer spell in the afternoon it was cloudier from 1500 GMT with a moderate shower (3.5 mm) at 1530 GMT. By evening pressure was rising keeping dry under broken cloud. Following the strong winds there has been some leaf-fall from beech trees. The wind has also brought down hundreds of beech nuts that lie open on the ground with the seed exposed. This is the most abundant crop since at least 2000. The seed are sought out by birds, particularly wood pigeons, and squirrels. Since the culling of the grey here there are none and we await, hopefully, the return of the red not seen here for 20 years. Similarly the conifers seem to have produced abundant cones this year, the most since 1995 and 1983. {Keswick, Cumbria 52.8 mm; Colwyn Bay 8.3h; Valley, Anglesey 6.6h}. [Rain 5.7 mm; Max 14.7C; Min 8.9C; Grass 8.0C]
6th: Showers resumed from 0430 GMT (2.2 mm) and by 09 GMT following further light showers the sky still looked threatening under complex cloud formations. There was a trace of pale coloured dust seen and cleaned off observing surfaces. Later forward trajectory analysis, using the HYSPLIT transport model at the NOAA ARL Website, indicted that dust-laden parcels of air leaving Iceland at 06 GMT yesterday could have travelled directly over Anglesey. Backward analysis confirmed parcels of air arriving between 100 and 500 m above ground had been over and S of Iceland between 18 GMT on the 4th and 09 GMT on the 5th (yesterday) and could then have picked up the dust. Pressure had risen to 1007 mb with the low (983 mb) SE of the Orkney Islands. The wind was a force 5 WSW'ly and some blustery light showers continued at first. By noon it was brighter with the sky clearing to give a mostly sunny afternoon. In the garden 2 comma and 2 red admiral butterflies in excellent condition were spotted enjoying the sunshine and feeding on garden plants still in flower. These include fuchsia, French lavender and 'Brittany' sage. The night clear at first was overcast after midnight with some rain. [Rain 1.7 mm; Max 13.6C; Min 7.7C; Grass 6.2C]
7th: Overcast at dawn with tail of occluded front from low(996 mb) N North Sea over North Wales. By 09 GMT the cloud was breaking up and there were bight spells, but over Snowdonia the cloudbase was at 12000 ft, or below in the Nant Ffrancon Pass, giving hill fog. The NW'ly wind was light and pressure was 1015 mb. The morning was mostly cloudy but by noon it was sunnier. Persistent linear convective clouds developed across W Anglesey crossing the Strait and over Snowdonia. The cloud was dark and thick enough to give a shower of rain in Caernarfon between 1230 and 1300 GMT. Towards evening the cloud dispersed completely giving a sunny end to the day and a clear evening with a peach-coloured sky . A mostly clear night but there was some patchy cloud at times. [Rain 0.1 mm; Max 15.9C; Min 7.3C; Grass 4.1C]
8th: Minimum temperatures overnight were 5.6C (air) and 1.9C (grass) and there was heavy dew. These were lowest for air since 5.3C on 20 April and 2.8C on the 19th that also saw 0.4C on the grass. There was quite an autumnal feel to the morning and one which should enhance autumn tree leaves colours. The sky was almost clear but there were some clouds low to the NE seen over Liverpool Bay (possibly over Cumbria) and some cumulus to the S behind the mountains. There was thick smoke haze with the mountaintops >3000 ft looking somewhat clearer. Pressure was 1021 mb with Atlantic-high (1030 mb) to the W and low 9991 mb) off the Iberian Peninsular tracking N. There was a light E'ly breeze and after a little cloud formed in the morning the afternoon was mostly sunny. The evening and night were also clear. {Sunniest Valley 10.1h sunshine} [Rain 0.0 mm; Max 14.5C; Min 5.6C; Grass 1.9C]
9th: A sunny morning but after after heavy dew the grass was slow to dry even in the moderate E'ly wind as the relative humidity was still at 90% at a temperature of 8.7C (dewpoint 7.2C). Pressure was 1023 mb with the high 1029 mb off NW Scotland. The low was (982 mb) near cape Finisterre tracking N. This had already brought strengthening winds to the Channel and SW England. Here it was a pleasant morning with plenty of sunshine between cumulus clouds being swiftly blown along on the wind. After some good spells of sunshine it was cloudier later with some dark clouds drifting across before evening, but there was no rain. {Sunniest Valley 8.6h sunshine}[Rain 0.0 mm; Max 13.2C; Min 6.7C; Grass 4.0C]
10th: Dawn was overcast but by 09 GMT some breaks were already appearing in the cloud. More than 200 redwings, in several groups, passed over the weather station migrating in a S'ly direction. They may have crossed over to Scotland, possibly from Scandinavia or more likely from Iceland, and have been working their way down the west coast. Originally of the same Fennoscandian species Turdus iliacus the Icelandic birds are now regarded as a distinct race coburni. Colonising Iceland since the last Ice Age, 10,000 years ago, they have adopted a distinct migration pattern flying directly in October to France or the Iberian Peninsula to overwinter. Numbering up to 300,000 pairs they mostly all leave the island and will return in the spring. The redwing that can be seen here during the winter are different birds. Pressure was 1019 mb with high (1025 mb) just N of Scotland. The vigorous low (990 mb) had started to fill and was over the Bay of Biscay. Frontal cloud was lying over N Spain to Brittany and down through the middle of France. A thundery frontal low was moving along the south coast from the Pyrenees generating thunderstorms (Nice at 09 GMT) and heavy rain. Here in the moderate to fresh E'ly wind more breaks appeared in the cloud as the day progressed. Before noon a clear slot was established overhead. There was thick smoke and or dust haze at first, but this thinned during the morning. It was a sunny afternoon with orographic wave clouds persistent in the vicinity. Cloud was seen almost stationary over the Snowdonia Mountains and to the west where it kept mostly cloudy (see NOAA satellite images). The night was mostly clear at first, but became cloudier later. [Rain 0.0 mm; Max 14.5C; Min 8.3C; Grass 6.7C]
11th: Another grey dawn but it was soon brightening as the complex of stratocumulus, cumulus, altocumulus and a little cirrus clouds began to disperse. At 09 GMT together with much organic debris on observing surfaces there was a little more pale brown dust. Pressure was 1017 mb with the intensified high (1034 mb) moved over the North Sea to S Sweden. The slow-moving low (992 mb) over the Bay of Biscay was continuing to give strong winds in the Channel. Here it was another mostly sunny day with more orographic wave clouds. The temperature rose to 14.5C, one of the highest in the UK. Just before the sun set a partial sundog was seen in thin cloud. After dusk the sky cleared with bright stars seen at 21 GMT but there was cloud later in the night. {Jersey 14.1C; Valley 14.2C} [Rain 0.0 mm; Max 14.5C; Min 7.5C; Grass 4.5C]
12th: Early cloud began to dispersed here before 09 GMT but at Beaumaris, although there were clouds over the Snowdonia Mountains, there was clear sky over the Menai Strait where a fresh (f5) E'ly wind was roughing up the water on the high tide. It was very hazy; the haze was probably composed of a mixture of Icelandic-dust and pollution smoke. A deposition of very pale brown dust (Munsell colour chart 10YR 8/4) was observed at 09 GMT. During the morning the blue sky became increasingly paler (dust) while the characteristic coloured hue of the smoke can be seen low on the horizon in the image looking SW from Beaumaris. Forward trajectory analysis, using the HYSPLIT model at the NOAA ARL Website, confirmed that low-level parcels of dust-laden Icelandic-air were, after being caught in the Biscay-low on the 9/10th, elevated to over 4000 m to be over Wales and England by today. Pressure was 1012 mb with the low now filled to (1002 mb) over the Cherbourg Peninsular, N France, while the high (1040 mb) was over Lithuania (E of the S Baltic). To the NW, just of the W coast of Iceland, was deep low (981 mb) with fronts to the W of Ireland. The morning was sunny, but as frontal cloud moved N and patches of rain moved N. The afternoon became calm and increasingly murky with thickening haze and poor visibility by 17 GMT when a further trace deposition of pale brown dust was seen. By 18 GMT the low (1005 mb) was approaching the Midlands and some rain had reached Edinburgh. Rain did not reach here from that system with the night continuing dry. [Rain trace; Max 14.0C; Min 7.5C; Grass 4.5C]
13th: A partially cloudy but bright dawn with a little red sky warning seen in the E. Just before and after 09 GMT there was a light shower of rain and further showers (heaviest about 1130 GMT) but totalling only 0.5 mm. Most of the rain was S and N of Anglesey as the occluded front moved across Wales. The front was associated with a low (994 mb) SW Ireland tracking NE. The front cleared by 14 GMT and introduced a showery airflow with cumulus and cumulonimbus clouds developing through the afternoon. A shower at 1440 GMT over Mynydd Llwydiarth, to the NE of the weather station, resulted in a partial but brilliant double bowed rainbow viewed in Pentraeth. Before dusk the sky was mostly clear leading to a cool night. [Rain 0.5; Max 14.0C; Min 6.8C; Grass 2.5C]
14th: With a few clouds over Anglesey the sky was sufficiently clear for the air temperature to fall to 5.6C, but it fell to 0.6C on the grass and was the lowest of the month. On the low-lying, and by now partially flooded, Malltraeth Marsh temperatures in the hollow were lower. With air temperature around 1C there was frost at Malltraeth where early motorists had to clear their windscreens of ice for the first time this autumn. The mountaintops were clear at first with the Snowdon summit AWS reporting a temperature of 3.2C at 09 GMT, here it was 8.1C. The sky over the Menai Strait was partially clouded with altocumulus, but cumulus and cumulonimbus clouds soon developed with heavy showers and sferics reported along the N of the island and Colwyn Bay. Pressure (995 mb) was still falling with low (989 mb) near Brighton tracking NE into the North Sea. Pressure was low (993 mb) N Scotland and (991 mb) S Iceland. The morning became mostly cloudy with more showers around noon as a line of showers moved across the Irish Sea. Small hail was reported at RAF Valley, while a downpour in the outskirts of Caernarfon half an hour later led to field runoff-water partially flooding Bangor Road. The afternoon brightened, but then intermittent light rain returned during the evening and night. [Rain 17.2 mm; Max 11.2C; Min 5.6C; Grass 0.6C]
15th: There was a heavy burst of rain about 0115 GMT as more showers arrived and these continued until morning. At 09 GMT the sky was threatening with low ragged cloud obscuring the mountains and visibility was poor. Pressure was 994 mb with complex low-pressure (992 mb) over the UK. Pressure was high 1028 mb Azores, Greenland (1033 mb) and Russia (1035 mb). Clusters of showers were widespread but the morning kept mostly dry until around noon when there were some here. The afternoon kept mostly cloudy but it did brighten up again with the odd glimpse of the sun before dusk. The evening was mostly overcast. [Rain 11.7 mm; Max 11.3C; Min 6.5C; Grass 2.8C]
16th: At midnight low (993 mb) was near Skegness tracking towards Birmingham. An associated active front passed over here and around 0149 GMT there was a hailstorm with stones of more than 7 mm diameter (remnants were measured at 09 GMT after melting for 7 hours), estimated to have lasted about 5 minutes, that covered the ground and contributed most to the 11.7 mm of melt water collected in the raingauges in the morning. This was a very heavy fall, equivalent to about 140 mm per hour! At the end of the hailstorm (0154 GMT) there were 4 close proximity lightning strikes and heavy thunder. Further sporadic thunder was heard for another 10 minutes as the storm moved away. During the storm there was a rapid temperature fall of about 2.5C to the overnight minimum of 7.5C. At 09 GMT there were small breaks between mainly cumulus clouds. A cumulonimbus was spotted in the vicinity and distant thunder heard over the mountains of Snowdonia. Pressure 996 mb was rising with the low (994 mb) still near Birmingham and frontal cloud over South Wales. Slowly the morning brightened with some sunny spells developing. The temperature on the summit of Snowdon during the night was around 2C so sleet and other ice precipitation was possible. The afternoon was mostly cloudy with towering dark cumulus across the island (see ground and satellite images captured within 11 minutes). Later as the sun became lower some cumulus were backlit with frequent crepuscular rays and episodes of precipitation or sometimes virga (where the precipitation falls short of the ground). Sight of the mountaintops eluded me all day as they were obscured in cloud.
17th: With cloud still obscuring the mountains above 2800 ft the morning remained almost overcast with frontal cloud slow to clear. Pressure 1004 mb was rising with low-pressure over the North Sea (995 mb) filling and Baltic (991 mb) deepening. Pressure was high (1041 mb) and intensifying over Greenland. There were scattered showers across the UK, but it kept dry here well into the evening. There was showery rain (3.2 h duration) from 21 GMT that continued until just before 07 GMT. At 09 GMT the sky cleared rapidly over Anglesey leaving cumulus clouds to the W and over Snowdonia. Pressure 1008 mb was rising in a ridge of high-pressure from the SW. Low (984 mb) was over the Baltic and low (989 mb) was just SE of Iceland with an associated cold front lying to the NW. Low (993 mb) was lying just W of the Iberian Peninsular. The morning sunny at first became overcast by noon. Later there were some sunny spells as the cloud eventually cleared over the Carneddau Mountains but not around Yr Wyddfa before dark. From 21 GMT there was showery rain (duration 3.2 h) that continued until morning. [Rain 4.0 mm; Max 13.0C; Min 8.0C; Grass 7.0C]
18th: With the last of the showers ending just before 07 GMT the sky rapidly cleared. At 09 GMT the sky over Anglesey had cleared leaving cumulus clouds to the W and over the mountains of Snowdonia. Pressure 1008 mb was rising in a weak ridge of high-pressure from the SW. There was an intensifying high (1043 mb) over Greenland while low (984 mb) was over S Sweden. Low (993 mb) was W of Iberia moving an active front into Portugal. To affect us later was low (989 mb) SE Iceland with an associated cold front to the NW and a developing low off the Western Isles. This would move SE into Ireland by nightfall. The morning was sunny at first but cloud developed around noon. Later sunny spells developed as clouds cleared to reveal the tops of the Carneddau Mountains but Yr Wyddfa remained shrouded in cloud. By evening rain had moved into Ireland on the slow-moving cold front and ahead was a line of showers on a trough. This arrived about 03 GMT and gave light to moderate rain until 05 GMT. [Rain 4.5 mm; Max C; Min 5.7C; Grass 3.0C]
19th: At 06 GMT the cold front was over E Ireland and the trough was clearing Anglesey and the Isle of Man. By 09 GMT the sky was clearing (6/8) with cirrostratus, cumulus and altocumulus clouds in the vicinity. Pressure was 997 mb with a new deepening low (991 mb) W of Scotland and (989 mb) unchanged S of Iceland pulling down cold air from the Arctic. Low (989 mb) off the Iberian Peninsula was tracking NE. The morning was bright at first but soon became dull as the weakening cold front crossed the Irish Sea. There was rain from soon after 1100 GMT becoming heavy just before 1300 GMT turning showery later on. As the cloud began to clear at sunset there was a vivid pink and purple turning red sky at 1718 GMT, a lull before yet more rain before 2000 GMT as more frontal cloud moved in from the SW. Rain was light to moderate through the night accumulating 18.6 mm by morning bringing the total for month to 109.2 mm and the year to October 963.2 mm that ranks 10th. [Rain 18.6 mm; Max 12.3C; Min 6.7C; Grass 3.5C]
20th: It was still raining lightly at 09 GMT with frontal cloud over Wales and N England. There was a large patch of heavier rain lying to the NE with snow having fallen over the tops in the Highlands of Scotland. Pressure was 992 mb with complex low-pressure lying Cape Finisterre (987 mb) to Brest, and (984 mb) deepening W of Ireland and tracking towards St. George's Channel. With the rain dying out during the morning it was a little brighter but it remained overcast with hill fog around the mountaintops of Snowdonia. The afternoon kept overcast, dull with little (E'ly) or no wind. The temperature kept <10C through the day and more frontal rain arrived about 2030 GMT. Although the temperature rose to 10.3C around midnight, it was the lowest maximum of the month. [Rain 18.4 mm; Max 10.3C; Min 5.8C; Grass 5.5C]

21st: With the low deepening to 978 mb it was over the Irish Sea and Anglesey by midnight. There were strong gale to storm force winds in the English Channel. Here the wind that had been E'ly soon backed W'ly and strengthened to gale force 8. At RAF Valley gusts of 52 mph were reported. There was moderate to heavy rain, and a downpour at midnight with the temperature falling from 10.3C, (maximum for the 20th) to the minimum (for the 22nd) of 5.3C. The distribution of rainfall in relation to position of the low and fronts marked on the midnight Met Office analysis chart can be seen on the graphic. The rain had stopped just before 0300 GMT. By morning the wind was WSW'ly force 6 and there was a moderate shower of ice pellets at 0805 GMT. At 09 GMT the ground was waterlogged but I was able to complete the observations in the dry between showers. Pressure 992 mb was rising with low (973 mb) near Dundee, Scotland within complex low-pressure over the British Isles. The morning continued with blustery showers including a few more ice pellets. The afternoon saw further heavy rain and strong to gale-force wind; at 1320 and 1325 GMT there was heavy thunder and lightning that knocked out a substation in Benllech cutting the electricity supply over a wide area for up to 90 minutes. More thunder was heard at 1420 GMT. At Penygroes near Caernarfon part of the roof at the Kruger Tissues factory was torn away crashing into the car park. Emergency Services were called but none of the 120 workers were hurt. With the soil now saturated and rivers at a high level there was localised flooding at Llanrwst in the Conwy Valley. Although conditions were described as 'horrendous' I had not yet seen any reports of serious flooding of property. Earlier this year (3 February 2004) there was extensive flooding. [Rain 10.5 mm; Max 12.5C; Min 5.3C; Grass 3.8C]

¤ 22nd: Continuous heavy rain at 0900 GMT with water already standing around the weather station. Pressure 998 mb was falling with low (988 mb) SW of Ireland with associated warm front over Wales. Anglesey and Snowdonia were under a deluge of rain that was to accumulate 30.0 mm here by noon when it was still raining heavily. Between 1100 GMT and 1130 GMT rain fell at a average rate of 15.4 mm per hour with a maximum near 20 mm per hour. There was minor flooding at the weather station as a stream of runoff water from higher fields ran through the garden on to the road where it was up to 15 cm deep. At the bottom of the road the A5025 Menai Bridge to Pentraeth road was flooded with up to 2 ft of water, between Wern Farm and Pentraeth Automotive at Henffordd, and was impassable to light vehicles and cars causing a long tailbacks. To alleviate the problem a stone wall was breached in 3 places to let water flow on to a lower-lying fields. Anglesey Highways reported that flooding was particularly bad in the SE corner of the island including in Llansadwrn, Llanfaes, Llangoed and Beaumaris. The Llansadwrn to Beaumaris road was closed with deep water on the section near the Almshouses, vehicles were abandoned. Again a wall was breached to allow flood water to flow off the road. The road between Beaumaris and Llangoed was deeply flooded; a trapped car floated away. The Llangefni to Benllech road was closed and other roads in the area were either impassable or difficult. The Castle moat in Beaumaris was flooded and overflowing threatening nearby properties. At midday the only road open, with care, from Llansadwrn to other parts of the island was the Pentraeth to Llangefni via Talwrn On the W coast of the island the road between Bodorgan Primary School and Bethel was flooded. On the mainland in Gwynedd flooding occurred at Talybont, Curry's Store in Bangor and Ysgol Maesincla School in Caernarfon. Some local authority workers in low-lying offices on Anglesey were sent home as water began to rise. Carers had to use 4x4 vehicles to reach scores of dependant people in their homes across the island. The rain eased a bit in the afternoon with the wind strengthening to strong to gale-force for a time. On Snowdon gusts of up to 93 mph were recorded at the Clogwyn AWS. More heavy rain was falling at 1400 GMT with much of Anglesey, and parts of Gwynedd under water. Flooding was reported in Anglesey, Bangor and Caernarfon and several roads were closed; the Emergency Services dealt with more than 100 flooding incidents. In Wales 14 river flood warnings and 40 flood watches were issued with the Conwy and Dyfi Valleys affected. Pupils at Ysgol Dyffryn Conwy School in Llanrwst were sent home after lunch as water levels began to rise. Parts of Llanrwst were flooded, but this time no water reached the centre of the town. Trains services, however, between Blaenau Ffestiniog, Llanwrst and Llandudno were suspended due to rising water. The Cambrian main line as well the line west of Colwyn Bay to Holyhead that had flood water on the line were closed. Traffic in Bangor during the day was described to be 'at gridlock'. The A55 Expressway was underwater in places near Conwy and Abergwyngregin and, together with long-term roadworks caused huge tailbacks (>10 miles reported) well into the night with some journeys from England taking up to 5-7 hours (normally just over an hour). On Anglesey several rivers and streams burst their banks including the Afon Nodwydd at Pentraeth, the Afon Braint at Pont y Crug. Up to 2 ft of flood water reported in several places. Over 2000 sandbags were issued during the day and more were on standby. Sandbags were used to protect properties in Gaerwen where a manhole cover was lifted and animals were rescued from flooded fields using a boat. The Council Offices and 14 businesses in Llangefni were flooded in the evening when the Afon Cefni River burst it's banks. Although sandbagged the flow of water was so great by 2230 GMT that they were overwhelmed. Telephone and IT facilities were severely disrupted with some having to move to the first floor to maintain services during the weekend. A bakery was also flooded in the town. With the high tide approaching around the coasts near 6 pm BST there was danger of further flooding in river valleys as water backed up against the rising tide. But as the tide was neap and only 7.9 m Liverpool, off the 9.8 m spring of a week ago, the risk was not as high as on previous occasions. The Proudman Oceanographic Laboratory's tide gauges recorded a surges of 0.5 m at Holyhead and just 0.2 m at the Gladstone Lock in Liverpool. This was unlike that of 3 February 2004 when extensive flooding occurred in Llanrwst and Trefriw due to a combination of high tide and heavy rain over the Snowdonia Mountains.

More severe weather (heavy rain) was forecast for Wales by the Met Office, Police advised motorists not to travel unless absolutely necessary due to the difficult conditions on nearly all roads. By 15 GMT just over 50 mm of rain had accumulated in Llansadwrn since 09 GMT this morning. By 18 GMT it had risen to 60 mm. With pressure still falling, and a frontal cloud triple point over Cardigan Bay with warm front over Anglesey, there was more rain during the evening and at 2010 GMT nearby lightning and thunder. By 21 GMT pressure was 995 mb and the rainfall total had reached 73 mm, and it was still falling. Water was up to 10 cm deep in places at the weather station and nearby roads were still flooded. Water was reported 'running in torrents' off Mynydd Llwydiarth where roadways were being washed away. At Benllech part of Beach Road was cordoned off because of the danger of landslip. During the evening in Beaumaris there was serious flooding up to 2 ft deep around Castle Street and Castle Square. Overnight the rain was lighter, but more or less continuous, bringing the 24-h (09-09 GMT) total to 86.0 mm. This was the largest 24-h fall at this station exceeding 69.1 mm recorded on March 21st 1981, but falling short of the Llansadwrn record of 127 mm on 10 August 1957. In the 24-h period up to 06 GMT on the 23rd Llansadwrn topped the list of wet places with 91 mm more than twice the 44 mm recorded at RAF Valley and exceeded the mountainous Capel Curig that had 83 mm. {Capel Curig 65 mm; Guernsey 18C} [Rain 86.0 mm; Max 13.5C; Min 8.0C; Grass 8.0C]

23rd: Well, it was still raining lightly under grey uniform stratus with very poor visibility. But the unexpected stream across the garden had stopped running and the standing water had disappeared. It was a dismal day with the rain soon turning to drizzle and mist, but the amount of rain water was small allowing mopping up across the island to continue. Calls to Emergency Services on Anglesey numbered over 300 in the past 12-h. About 0930 GMT the Fire Services with 5 appliances attended several properties in Beaumaris that had 5 ft of water in their basements as a result of the flooding. During the night Llyn Bodgylched Lake near the old Almshouses, 300 ft above Beaumaris, began to overflow flooding the B5109. A torrent of water ran from Baron Hill down the steep Allt Gôch Fawr Big Red Hill into Church Road where doorways had to be sandbagged. Later, runoff water that had also filled a natural basin between the allotments and the town overflowed and run into and filled the Castle moat. Sluice gates at the moat 'should have been opened to let the water run out' said one resident (but the gates were reported to be open). Up to 3 ft of water surrounded Castle Square and despite sandbagging water had been waist-deep at the bar in the recently refurbished White Lion. The Royal Anglesey Yacht Club was surrounded by water and several shops, hotels and houses flooded. Water was held back by a turf sea-defence bank surrounding the Green. Lifeboat crew started digging holes in the bank to let the water flow into the sea between 20 to 21 GMT. Eventually a digger was brought in by former mayor Laurence Roberts to hasten the task and succeeded in lowering the water level. This effort eventually reduced the level by about 1 ft. Around 01 GMT a manhole cover was removed, near the White Lion, with access to a pipe into the Menai Strait and the remaining water flowed away. The road between West End and Chimney Corner was also flooded. The lake at Llyn-y-Parc above Beaumaris had overflowed blocking the road to Llandegfan and water was 'roaring' down Allt Gôch Bâch Little Red Hill again flooding the road at the bottom of the hill. Nearby a landslide on the road to Gallows Point blocked half the carriageway and disrupted traffic on the road from Beaumaris to Menai Bridge. Visitors and some residents who could not reach their homes or accommodation were housed in Canolfan Beaumaris. There was extensive flooding in Dwyran where water entered several properties including the primary school, church, garage and the Anglesey Bird World.

In Bangor a small landslide on the Caernarfon Road disrupted traffic for a time. Train services Bangor were cancelled for the second day with flood water from the Afon Braint on the line at Llanfairpwll.

Pressure was 999 mb with another low (984 mb) lying to the W of the Bay of Biscay tracking slowly towards S Ireland. Ahead was another frontal system and triple point arriving over S England and South Wales during the morning. This brought heavy rain to Dartmoor, with more than 50 mm reported, and S and W Wales. Several homes in Briton Ferry, Gorseinon and Mumbles near Swansea were flooded. In nearby Neath the Metal Box Factory was surround by up to 2 ft of water. The rain headed N towards Snowdonia that, at first, gave some protection to Anglesey with the heaviest rain moving NE. It was dreadful weather for the annual Ffair Borth Menai Bridge Fair held for centuries on the 24th of October in the streets of the town, but because this year a Sunday it was held today instead. The afternoon became very misty with moderate fog developing before light rain commenced at 1500 GMT. There was a spell of heavy rain at 2100 GMT before it again turned light before ceasing about 05 GMT. [Rain 11.1 mm; Max 13.2C; Min 8.9C; Grass 8.1C]

24th: After the rain the sky cleared so that at 09 GMT there was just 3/8 cover. There was a drying fresh to strong S'ly wind. Pressure was 995 mb with the S Irish low (985 mb) near Valentia and the frontal cloud now to the N. It looked back to normal in Beaumaris with the usual coach loads of visitors arriving for a morning of sightseeing. In fine sunshine, and no sign of the flood water on Castle Street, they were looking mystified at the sandbags around shop doorways and the 'closed because of inclement weather' notice at the Castle. The kiosk had been flooded and although refurbishment was in progress there was no indication when it would reopen. There were several very disappointed families and children. This apparent normality hid the severe damage caused to many homes and businesses. Train services west of Bangor were cancelled for the third day running as they were in the Conwy Valley and parts of the Cambrian Coast line.

The morning kept dry but it did become cloudier by noon. Convective clouds developed in the afternoon and a rumble of thunder was heard at 1437 GMT. By 22 GMT the wind had strengthened to near-gale force 7 with strong gusts. The POL Tide Gauge at Llandudno recorded a 0.5 m surge on top of the predicted 7.0 m high tide at 2007 GMT. But as it was not a very high tide it was not a problem; the highest tides of the year will occur on the 27 - 30th of the month. There was a spell of light then moderate rain before it turned showery after 01 GMT. [Rain 3.4 mm; Max 14.5C; Min 9.8C; Grass 10.0C]
25th: Overcast with moderately low stratus cloud and heavy drizzle that by 09 GMT was intermittent light rain. Pressure was 996 mb with filling low (983 mb) moving away NE into the North Sea. The wind was a force 4 W'ly. The morning was dull at first with the rain petering out and by afternoon it was brighter with a few slight showers and some sunny spells. There were some clear spells at first at night but it was cloudier by morning. [Rain 0.3 mm; Max 11.0C; Min 9.1C; Grass 8.1C]
26th: A cooler night than of late with the minimum down to 4.2C, the coldest of the month. There was moderate to heavy dew on the grass with a minimum of 1.2C. Pressure had risen to 1010 mb, in a ridge moving across from the W, and by 0900 GMT the sky was clearing. It was a mostly sunny morning on Anglesey with a line of stratocumulus clouds across the Snowdonia Mountains. The photograph also shows what could be taken for the Menai Strait but is the flooded Malltraeth Marsh. The Afon Cefni River now flows within dykes. The geological fault line, along which the marsh developed, runs in the same NE to SW direction as the Strait. The marsh drainage scheme was completed in full in 1812. With greater environmental awareness today it is doubtful that the work would ever have been undertaken as it more or less destroyed an unique ecological habitat. At noon pressure was falling slowly with low (995 mb) over the SW of Ireland. But low (982 mb) to the W of Cape Finisterre tracking NE is the one to watch over the next few days. During the afternoon widespread convective clouds developed across Anglesey. Several showers occurred and in late afternoon low-angle sunshine rainbows were seen between 1500-1520 GMT. At the same time a cumulonimbus cloud was spotted giving a heavy showers in the Nant Ffrancon Pass and adjacent mountaintops. But towards evening the sky partially cleared and was so during the first part of the night. [Rain 1.1 mm; Max 12.9C; Min 4.2C; Grass 1.2C]
27th: With advancing frontal cloud it was overcast by dawn. At 06 GMT the low was (953 mb) to the SW with strong S'ly winds off Brittany and the Channel Islands. At 09 GMT pressure 996 mb) here was falling and there was a fresh SE'ly blowing off the mountains. With cap clouds over Snowdonia there were some small clear slots over the Straits and mostly it was cloudy. By noon the low was 953 mb off Brest while here it had fallen to 992 mb. There was some orographic cloud development, that looked dark to the E, and during the afternoon there were some light showers of rain. With the highest tides of the year tonight an anxious watch was being kept around south and western coasts. By dusk the strong winds and surge tide, described by an eyewitness as being several feet above normal, were affecting S Cornwall and it was reported that the sea wall in Penzance was starting to break up. In storm-force winds huge waves were breaking along the Cornish coast and there were reports of flooding by sea water in several seaside villages. The NTSLF tide gauges along the S coast of England (data courtesy of POL) recorded surges of 0.7 m at Weymouth, 0.75 m at Plymouth and 0.8 m at Newlyn. Here the SE'ly wind was moderate occasionally fresh (f5/6), being in the lee of the Snowdonia Mountains. Elsewhere the wind was stronger reaching gale force along Anglesey's E coast. The tidal surge recorded by the POL Tide Gauges at Holyhead was 0.6 m at 2200 GMT and at Llandudno 0.4 m at 2219 GMT. Breaks in the cloud continued through most of the night and we missed the bands of rain moving up the Irish Sea affecting S Wales and NW Ireland during the evening and night. [Rain 1.9 mm; Max 13.3C; Min 6.7C; Grass 3.7C]
28th: At midnight the low was (959 mb) near Bantry Bay in the SW corner of Ireland. It was warmest for several hours after midnight with the temperature reaching 13.3C. Just before 07 GMT the temperature dipped to 9.5C in showers of rain. When these past to the N the sky rapidly cleared; at 09 GMT there were just a few altocumulus overhead and cumulus to the S over the Llyn Peninsular. Pressure was 985 mb with the low (956 mb) moved SW off S Ireland. Winds were still strong within it's circulation but were moderating over the UK. The morning was sunny with the force 4 SSE'ly wind lessening. With some leaves still on some of the most sheltered trees good autumn colours have developed on birch, beech and horse-chestnut. With another high tide this morning at 1100 GMT in the Menai Strait sea defences were again tested. The POL Tide Gauge at Holyhead recorded a 0.5 m surge; surges can affect low tides as well and the low at 04 GMT was about 0.7 m above the predicted level. By afternoon it was cloudier, but there were sunny spells and the temperature rose to 16.7C, the warmest of the month. The night was partly cloudy with a halo seen around the moon at 21 GMT. There were bands of rain both to the N and S of Anglesey. [Rain 2.7 mm; Max 16.7C; Min 9.5C; Grass 7.7C]
29th: With low cloud and mist around the mountains there was intermittent slight rain here. With the addition of this morning's rainfall contribution the October total reached 244.6 mm, the 2nd wettest on record. Pressure was 987 mb with the low (969 mb) near Lands End. Pressure was high (1017 mb) in mid-Atlantic and (1018 mb) N Sweden. Occluded frontal cloud was lying over Anglesey and the Irish Sea resulting in a very dull days with slight rain at times. After dark cloud cover was variable at first then white lee-wave clouds, hung motionless over the weather station at 2100 GMT, being well-lit in the bright moonlight. It has also been very wet in S Ireland where today severe flooding was reported in Clonmel, Tipperary. The town is in the River Suir valley that is surrounded by mountains. With Comeragh Mountains to the S, Galty Mountains to the W with the river source to the N at Devils Bit 1577 ft the river has a large catchment area. Water was up to 6 ft deep was flowing through the town ruining many homes and businesses. The river runs on to Waterford in the SE corner of Ireland. In nearby Wexford there was also flooding, with water up to 5 ft deep. [Rain 1.2 mm; Max 16.0C; Min 9.4C; Grass 7.5C]
30th: Overnight the minimum of 9.9C was the warmest of the month. It was a showery start to the day but by 09 GMT these had clear away leaving fog in the Menai Strait and some lee-wave clouds to the S of the weather station. Pressure was 1007 mb was rising coming under the influence of Atlantic high-pressure (1022 mb) to the SW. The low had filled to (991 mb) now lying in N Bay of Biscay. The day was sunny with an almost clear sky and hazy visibility. At dusk low mist formed on the fields as heavy dew formed. Most of the night although visibility was poor it was bright with moonlight. [Rain trace (dew/fog); Max 14.6C; Min 9.9C; Grass 7.2C]
31st: Before dawn visibility was less than 100m but by 0900 GMT it had improved to <200 m (fog). Cloud was just visible and it was calm. There was heavy dew and fog deposition on the grass that amounted to 0.6 mm measured by lysimeter; a little condensed on the raingauge funnel and dripped into the bottle, but it was <0.05 mm counting as a trace. A further 0.06 mm dripped into the bottle just after 0900 GMT, measured the next morning, both readings in total under-measuring this type of precipitation. Pressure had risen further to 1022 mb with Atlantic-high (1024 mb) over Ireland, Wales and central England. The morning kept dull but 1 or 2 small breaks in the cloud developed by midmorning with some mountaintops appearing in the gloom over fog still in the Strait. The afternoon was brighter but it remained mostly cloudy but dry.

Rainfall at the end of the month totalled 246.2 mm. It was the 2nd wettest October and only the 3rd wettest of ANY month recorded in Llansadwrn. The total for the year stood at 1100.1 mm, the 5th wettest on record here since 1929 requiring only 11 mm more to be placed it 2nd). [Rain 0.1 mm (dew and fog); Max C; Min 6.4C; Grass 3.5C]

November 2004

1st: A dry, bright and calm start to November. Pressure was 1025 mb within high (1026 mb) centred near Dublin. Several small lows and frontal cloud were in the Atlantic to the W of Ireland, but the day continued bright with a few sunny spells during the afternoon. At night there was moonlight through a thin veil of cloud and although thickening by morning there was no rain. Following a series of earth tremors (2.7 on the Richter scale) a volcano erupted on Iceland at 2150 GMT this evening. [Rain 0.0 mm; Max 11.1C; Min 9.0C; Grass 7.8C]
¤2nd: Another bright and dry morning under a complex of clouds. Pressure 1020 mb was falling with the high (1029 mb) moved away E to be over S Sweden. Lows and frontal cloud were still threatening to the W but frontal cloud over the Channel and S coast of England worked it's way N and brought some spots of rain then drizzle from 1330 until 1530 GMT.Although then dry the sky remained thickly overcast with stratiform cloud and there was a light shower at 1800 GMT. Flights over Iceland were diverted to avoid the plume of ash and smoke drifting in a NE'ly direction towards Norway from the Vatnajokull volcano. The plume was estimated as being over 10 km high, with plume temperatures less than -50C (see satellite image). There were frequent flashes of lightning in the plume. Lying under Grímsvötn, Europe's largest glacier, it had over some weeks, melted the 600 ft of ice above it causing a glacial flood before erupting. This is a fairly common event; it has happened 13 times since the beginning of the 20th Century, the last in 1998. There was a deposit of a light brownish-grey dust (Munsell Colour Chart 10YR 6/2) in rain at 1800 GMT, this did not come from the Vatnajokull volcano but from Algeria. Backward trajectory analysis using the HYSPLIT model at the NOAA Air Resources Laboratory indicated that parcels of air could have picked up the dust over northern Algeria between the 26-27th October. [Rain trace; Max 11.5C; Min 5.7C; Grass 2.5C]
3rd: An overcast and dull morning with only moderate visibility in thick haze. With the high (1035 mb) now over Russia pressure here 1012 mb continued to fall slowly. Complex lows (981-985 mb) were over Iceland and associated frontal cloud moved into the NW during the afternoon. There was a little rain around noon then some heavier showers in Caernarfon and N Anglesey during the afternoon. Cloud on a cold front brought rain into N Ireland and W Scotland by 18 GMT reaching here at 2300 GMT. Light rain continued until 0100 GMT before petering out. [Rain 3.8 mm; Max 12.8C; Min 7.2C; Grass 3.5C]
4th: After the rain the sky had cleared by dawn and it was a sunny start to the day. Pressure 1019 mb had risen under the influence of Azores high (1027 mb). An almost clear sky at first with a bank of orographic cloud over the mountaintops of Snowdonia but some cumulus clouds were seen low on the horizon in the W. During the morning more convective clouds formed but their development was limited in the afternoon and the day kept dry. The 12.9C maximum temperature was the warmest of the month. By evening the sky had mostly cleared again but showery rain was affecting Scotland. [Rain 0.0 mm; Max 12.9C; Min 5.5C; Grass 1.2C]
5th: It became cloudier after midnight; by dawn the sky was an almost covered by moderately high uniform grey stratiform cloud. Pressure 1031 mb continued to rise as high (1034 mb) approached SW Ireland. But a complex low-pressure system S of Greenland had an associated warm front approaching the W of Scotland. This gave rain to NW Scotland and NW England by afternoon and it arrived here by 01 GMT and was light to moderate through till morning. [Rain 7.4 mm; Max 11.2C; Min 6.8C; Grass 2.2C]
6th: Continuous light, the total accumulated over 8 h was 7.4 mm at 09 GMT. The ground was wet and water, was puddling underfoot, but not standing. It was overcast with a light WNW'ly wind and visibility was poor with light rain or heavy drizzle continuing into the evening. The night was drier but still overcast resulting in a small range of temperatures. Snow fell on mountains of up to 8000 ft in southern Norway, E and N of Bergen. [Rain 5.6 mm; Max 11.7C; Min 7.9C; Grass 4.0C]
7th: More of the same, low uniform grey stratus cloud. Pressure was high (1032 mb) just SW of Ireland and although here it was 1028 mb with the entrapped thick cloud it did us no good at all. The day kept dull and damp with occasional spells of fine or heavy drizzle. The autographic rainfall recorder showed 10.5 h of rain (>0.1 mm per h) and accumulated 3.1 mm by morning. [Rain 3.1 mm; Max 11.0C; Min 9.5C; Grass 9.0C]
8th: A large sunspot sent out another solar flare and this resulted in an intense geomagnetic storm after midnight but unfortunately, once again, it was overcast so no aurora were seen here. It had been raining lightly since 06 GMT and at 09 GMT visibility was poor. Pressure 1022 mb had fallen a little as the high (1033 mb) drifting further into the Atlantic. Low pressure was over the UK associated with frontal wave low (1014 mb) in the S North Sea. Low (996 mb) now over S Italy has resulted in heavy rain in the region but snow on the Alps where up to 45 cm fell. Here the wind was a light N'ly and, as the frontal cloud moved S, by 11 GMT the sky had brightened and there was a little sunshine. The afternoon was mostly cloudy with occasional slight showers; during the night frontal cloud associated with a low near Iceland moved across from the W. [Rain 1.3 mm; Max 11.6C; Min 9.5C; Grass 9.0C]
9th: After some drizzle and showery rain around 05 GMT the sky was still overcast at 09 GMT. Pressure was 1017 mb with low (983 mb) off Iceland having frontal cloud moving W to E across Britain. High (1037 mb) was in mid-Atlantic while pressure remains low in the Mediterranean. Brighter sky to the W gradually moved across and Anglesey became mostly sunny by noon. The Snowdonia Mountains were shrouded in cloud all day ; with the temperatures on the summits cooling to around 1C by 18 GMT there was the chance of wintry precipitation. The evening was clear at first but had become cloudy just as the geomagnetic storm intensified. Spectacular green-coloured sheets of aurora were seen in Perthshire, Scotland. [Rain 3.4 mm; Max 11.2C; Min 6.7C; Grass 2.2C]
10th: There were some showers of rain just after midnight but by morning the sky was clearing. At 09 GMT just half-covered with good sunshine over Anglesey with stratocumulus and cumulus to the S and over the Snowdonia Mountains. Pressure was 1020 mb with the Atlantic-high (1039 mb) anchored to the W of Ireland. We were in a N'ly airflow with frontal cloud lying to the N and E. Some limited sized cumulus did develop during the day but it kept mostly sunny and dry. Widespread orographic-wave cloud formations occurred over the UK (see satellite image). Showers over the mountaintops led to a very small scattering of ice/snow on Carnedd Llewelyn and Yr Wyddfa during the afternoon. [Rain 0.4 mm; Max 10.5C; Min 5.8C; Grass 2.1C]
11th: With a warm front lying to the NW it was back to low stratiform cloud and drizzle. Visibility was deteriorating and by 09 GMT it was <200 m (so was classed as fog). Pressure was 1023 mb with the anchored high (1040 mb) to the W and there was little or no wind. Low cloud persisted all day with fine drizzle that did not appear to show up on rainfall radar. The night was somewhat drier but remained overcast. [Rain 3.3 mm; Max 11.6C; Min 6.4C; Grass 3.9C]
12th: More of the same low cloud and intermittent light rain. Pressure was 1021 mb with anchored high (1037 mb) to the W and lows (996 mb) N Norwegian Sea. As a result we were in a NW'ly airflow that introduced cooler temperatures; the warm front was making slow passage SE over the English Channel while the cold front was just to the N. Winds were strong in the North Sea where isobars were tightly packed. The morning here was overcast and dull at first but brightened after passage of the weak front. Snow fell on the Cairngorm Mountains during the day. There was a little sunshine in the afternoon but it was colder and it turned cloudier again as convective clouds developed before dusk. It was a showery and blustery evening, with possible sleet even at low levels, and snow falling on the central and western peaks of Snowdonia where temperatures had fallen below freezing. Later the sky partly cleared. [Rain 1.6 mm; Max 11.5C; Min 9.0C; Grass 7.9C]
13th: Moderately high cloud just above the mountaintops and very good visibility in clear air gave a good sighting of thin snow cover above 2500 ft around Snowdon and the Glyders. Pressure 1038 mb had risen with high (1034 mb) weighing anchor and drifting E. Since yesterday evening there air was relatively dry and clear through the night. The temperature at 09 GMT was 7.0C and with dewpoint 0.1C relative humidity was 61%. The dry air had dried off the concrete and grass; the soil was still moist but had become less than saturated during the last few days. During the morning convective clouds developed in the N'ly polar maritime airflow having increased moisture content over the still-warm (13C) Irish Sea. This resulted in frequent showers off the sea across Anglesey, and W Wales during the day. The morning was mostly cloudy with a few spots of rain; in the afternoon showers were more frequent and some merging to give longer spells of rain. The showers lessened during the evening and the night became dry. [Rain 3.6 mm; Max 9.5C; Min 4.5C; Grass 2.5C]
14th: Another cloud covered sky, the cloudbase today was just above the summits of the Carneddau but was lower further to the W around Snowdon. There was a covering of snow above 2800 ft across the Carneddau, with Foel-fras well white-capped, and around Snowdon was similar. But the temperature on the summits was rising, 0.7C at 09 GMT rising to 2.5C at 18 GMT, and snow was expected to thaw although there was some further wintry precipitation. Pressure at 09 GMT was 1037 mb within high (1041 mb) lying to the SW. Low stratiform cloud persisted over most of the W during the day. There was clearer sky with some sunshine just to the E of the Carneddau but Cheshire and the Welsh Borders were also cloudy. It was a cool day with a maximum of 8.0C. The night was cloudy but dry. [Rain 0.2 mm; Max 8.3C; Min 3.4C; Grass 0.4C]
15th: Overcast with some intermittent slight rain beginning just before 09 GMT. Pressure 1028 mb was falling along with out high (1036 mb) still anchored to the SW. There was deep low-pressure (967 mb) over N Scandinavia with strong winds in the N North Sea. Frontal cloud was slow-moving over Scotland. The day continued with intermittent slight rain with the cloudbase descending giving hill fog across Snowdonia. There was a small range of temperature (<2C) through the day and into the night. [Rain 1.0 mm; Max 10.6C; Min 6.0C; Grass 6.0C]
16th: At midnight a shallow low (1016 mb) was sliding towards Scotland on the slow-moving frontal system still just to the N of here. By 06 GMT there was little change. At 09 GMT pressure here was 1026 mb with high-pressure (1036 mb) lying to the SW. The temperature was 10.6C, the warmest of the past 24-h and on the summit of Snowdon the AWS was indicating a warm 7.1C. The day was overcast, sunless and dull with drizzle from 1600 GMT as slow-moving rain over the Irish Sea edged closer. Later it became windier with the WSW'ly reaching force 5/6 around midnight. [Rain 3.4 mm; Max 12.3C; Min C; Grass C]
17th: At midnight low (999 mb) was close SW of Iceland and this deepened to (994 mb) S of Iceland by 06 GMT and tracked towards the Baltic during the day. Frontal cloud systems were lying just to the NW and there was rain from 07 GMT. This was heavy over Snowdonia but with temperatures on the summits around 9C no chance of snow. The overnight minimum here was 10.5C, warmest of the month and the only double-digit figure. Pressure here at 09 GMT was 1020 mb and there was light to moderate rain in a force 4 WSW'ly wind. Visibility was poor with low cloud on the lower slopes of the mountains. Another sunless day with spells of light rain or drizzle. The temperature, that had hardly varied over the last 2/3 days, started to fall from about 20 GMT as frontal cloud moved S; there was rain from 2330 GMT until morning. [Rain 7.7 mm; Max 11.5C; Min 10.5C; Grass 10.1C]
18th: Continuous light rain with poor visibility at 09 GMT. With the low (973 mb) now over the Baltic pressure here 1016 mb had fallen a little, but it was high to the SW (1033 mb) and S. Fronts straddled the UK with a cold front lying over North Wales. There had been sufficient rainfall to bring the soil back up to saturation point; it was soggy with water squeezing from it under foot. There were some pools of water gathering on the road to Beaumaris, in the same places that flooded on the 22nd of October. But at least the breaches in the walls had not yet been replaced and it was flowing away. The day continued overcast with more light to moderate rain accumulating 15 mm by 18 GMT. The temperature just after 09 GMT was 6.1C, this was the day's maximum and lowest of the month, thereafter falling reaching 3.0C during the afternoon with sleet at the weather station around 1600 GMT and snow falling around 800 ft. Through thick cloud wet snow was seen as low as 1200 ft on the mountains. There were reports of snow at low level inland from the Peak District in N England, Chester and as far S as Wolverhampton and Coventry by 1900 GMT with up to 3 cm in places. Rain and sleet eased here by 1900 GMT; the 19.1 mm precipitation accumulated made it the wettest day of the month. [Rain 19.1 mm; Max 6.1C; Min 5.5C; Grass 5.1C]
19th: There was further rain, sleet and snow from 0100 to 0300 GMT, then showers from 06 GMT with cumulonimbus clouds in the vicinity on a trough over the Irish Sea and Wales. At 09 GMT snow was lying above 400 ft on the Snowdonia Mountains and was on the A5 road at Ogwen Cottage. There were moderate accumulations in places. Pressure was 1022 mb with high (1032 mb) W of Cape Finisterre and low (986 mb) now over Poland. There had been the first ground frost (- 1.2C) of the autumn an the air minimum had been down to 1.1C. The last frost was on the 17th April, so there have been 216 frost-free days between. The ground was very wet and soggy underfoot after the rain. The morning had a few brief sunny intervals between convective clouds, driven in off the Irish Sea on the N'ly wind on to Anglesey and the North Wales coast and through the Cheshire gap. Snow showers, some prolonged, continued across the mainland mountaintops. The satellite image shows snow in the Peak District and convective showers over North Wales. There is a warm front to the W over Ireland associated with low (986 mb) SW of Iceland, that has within the last days, become covered with snow. The spectacular NOAA satellite image, courtesy of Bernard Burton, also shows glacial melt and ash trail left by the Vatnajokull volcano that erupted on the 2nd. The islands topography is enhanced at this time of year by the low angle of the sun. Sunnier here for a while at first in the afternoon, then further showers of sleet from 1620 GMT and snow pellets at 1820 GMT before dying out for the night. [Rain 0.5 mm; Max 6.2C; Min 1.1C; Grass -1.2C]
20th: Overnight the air minimum was 1.0C, lowest of the month. Pressure 1024 mb was falling very slowly with frontal cloud encroached from the SW. From dawn showery precipitation was drifting across the Irish Sea and with still-low temperatures was falling as a mixture of rain, sleet (at low level) and snow over the Snowdonia Mountains. But with the front moving E temperatures began to rise from the 2.8C at 09 GMT, coolest for the next 24-h. The precipitation petered out during the morning moving S. The day was overcast with temperatures around 5C and as darkness approached I could still see snow lying on the mountains around 1500 ft. [Rain 2.9 mm; Max 9.8C; Min 1.0C; Grass -1.4C]
21st: During the night there was a band of rain from 0130 to 0400 GMT and by 09 GMT the temperature had risen to 9.8C, 2C warmer than Nice that still had the cool N'ly winds off the Alps. Most of the snow had melted but there was some lying around 2800 ft in parts and there were patches at 800 ft. Pressure was 1018 mb with frontal cloud across most of the UK. There was heavy precipitation over Scotland that would still have been falling as snow. But even here temperatures were rising, at the Met Office's Loch Glascarnoch AWS the temperature had risen from below -8C to 0C at 09 GMT. There was still plenty of snow to be seen via the webcam. Overnight Kinbrace in Sutherland had seen the temperature dip to -13.2C. The morning here was overcast and misty in low stratiform cloud that had turned to moderate rain by noon for a while around noon; there were further spells of rain in the afternoon. By evening the WSW'ly wind had strengthened to force 6 but had moderated by morning. [Rain 5.2 mm; Max 11.3C; Min 2.8C; Grass 2.4C]
22nd: A mild night with the air minimum 9.8C equalling the maximum of the 20th. The sky was almost overcast but the stratocumulus cloud was starting to break up at 09 GMT. Pressure was 1015 mb with low (988 mb) just off S Norway and high (1030 mb) was over Spain. During the morning sunny spells developed with gaps developing in the orographic cloud waves (see satellite image). By dusk it was overcast once again and there were a few spots of rain during the night. [Rain trace; Max 12.0C; Min 9.8C; Grass 9.0C]
23rd: Another cloudy start to the day but appeared to be thinning from day cool enough to produce dew drops on the grass. At 09 GMT it was just about 6 oktas cover with some altocumulus formed. Pressure 1027 mb had risen within a small ridge of high-pressure from high (1031 mb) over Spain. But we were between fronts associated with the low (981 mb) SE of Greenland. After the early brightness the morning became darker as cloud thickened but there were some bright even sunny spells over parts of the mountains in the afternoon. Although cloud it was dry, the first dry day since the 4th. [Rain 0.0 mm; Max 10.6C; Min 8.4C; Grass 4.8C]
24th: A uniform grey sheet of cloud except for some broken cloud over mainland mountains and coast to the W. Pressure 1027 mb was unchanged with low-pressure to the W and maturing low (989 mb) SE Greenland, and high over Europe (1035 mb) and Spain (1030 mb), where apart from some fog patches it was sunny. A weakening warm front was lying over the W of the UK. It was dry at first but there was persistent fine drizzle with some occasional light rain in the afternoon under a few clouds having limited convection. The middle of Anglesey was dry and favoured with some bright weather under thinning cloud (see satellite image). By evening the broken cloud reached here before becoming overcast again later and keeping mild. [Rain 0.8 mm; Max 11.1C; Min 8.6C; Grass 6.2C]
25th: Light showers from 06 GMT still ongoing at 09 GMT. Pressure was 1022 mb and we were still in the warm cloudy S'ly airstream. Weak frontal low (1003 mb) was just off the Western Isles of Scotland with cold air advection to the W of Ireland. During the day another frontal wave low developed over Ireland. The morning was overcast with good visibility at first but drizzle and light rain began to affect coastal area by the afternoon. There was intermittent rain here from 2045 GMT and a spell of light to moderate rain from 0330 to 0600 GMT as the frontal wave tracked across North Wales. In the 24-h period to 06 GMT on the 26th more rain fell at Valley (13.8 mm) and Capel Curig (18.0 mm) [Rain 7.8 mm; Max 11.2C; Min 8.5C; Grass 5.5C]
26th: A mild night, but after passage of the cold front the temperature began to fall and was lowest 9.0C at 09 GMT. Pressure 1019 mb was rising with ridge of high-pressure (1021 mb) W of Ireland. The frontal wave was in the North Sea off Hull with complex low-pressure over Scotland and N North Sea. During the morning some breaks in the cloud started to appear, but were short-lived with the afternoon keeping cloudy. But during the night there were some clearer spells, enabling the moon and stars to be seen, with somewhat lower temperatures of late. [Rain trace; Max 9.6C; Min 9.0C; Grass 8.5C]
27th: It became cloudier after dawn as a frontal wave (triple point) was moving close to N Ireland and thickening cloud soon brought rain to N Ireland and Scotland. As a result pressure 1022 mb here was falling with the minor ridge of high-pressure moving E. Visibility was very good, but cloud was hanging around the summits of Snowdonia giving hill fog. As the morning progressed the cloudbase lowered in a warm front and there was drizzle around noon. The afternoon remained cloudy but dry then the cold front passed over during the evening. There was moderate to heavy rainfall, with a few ice pellets, from 1830 to 2115 GMT (see rainfall radar image). The night was mostly cloudy with a few light showers turning to snow over the Snowdonia Mountains. [Rain 9.8 mm; Max 9.3C; Min 4.5C; Grass 0.9C]
28th: A bright start with a sprinkling of snow seen on the Carneddau Mountains with a little as low as 2800 ft. The temperature here at 09 GMT was 6.7C (dewpoint 3.1C) while on Snowdon the AWS was indicating 2.5C. Pressure 1017 mb was rising with Atlantic-high (1035 mb) W of Ireland with yesterday's low (1007 mb) in mid North Sea and fronts over N France. The morning was bright with well-developed cumulus clouds to the NW over the Irish Sea with wintry showers continuing over the mountains. During the morning it became dull with orographic cloud off the Irish Sea developed over Anglesey and North Wales (see satellite image: there is frontal cloud in the E and marine-type convection over the Irish Sea and St. George's Channel). In the lee of mountains to the S it kept sunny with Tenby reporting 6.9h sunshine, the highest in the UK, in contrast to Valley that had 3.6h. Just before sunset the cloud began to clear and the evening and night were partially clear. [Rain 0.0 mm; Max 7.3C; Min 3.5C; Grass -0.4C]
29th: Overnight with the grass minimum falling to -2.2C, lowest of the month, there was frost on the grass at dawn, but it soon melted in the bright start to the day. There was little or no wind but it had become cloudier since dawn. Pressure was 1022 mb within a ridge of high-pressure but low (980 mb) N Norwegian Sea had frontal cloud trailing to the NW while remnant frontal cloud was over the English Channel and near continent. The morning was bright; at 09 GMT the temperature was 2.7C while on the summit of Snowdon it was -0.6C with light snow on the ground. During the day the temperature on the summit fluctuated around freezing pint and there was a little snow left by dusk. The day kept dry but cloudy here with remnant warm front cloud slow-moving over Anglesey (see satellite image: it shows following cold front lying to the NW and high-pressure clearance further S). While being sunless it was bright, as the cloud was thin, but at Colwyn Bay it was sunny with a reported {5.8h}. The night was clearer with some bright moonlight at times as the warm front moved away. {Falmouth 8.4h; Guernsey 11C}. [Rain 0.6 mm; Max 8.8C; Min 2.1C; Grass -2.1C]
30th: A showery start to the day with towering cumulus clouds delivery a shower here at 0645 GMT. Pressure was 1009 mb at 09 GMT with frontal-wave low (989 mb) just to the N of Scotland with trailing cold front lying the the NW. The wind was S'ly and, for a while around 10 GMT, there were spectacular (orographic) lee-wave clouds appearing almost stationary in sky over the Menai Strait. They are formed downwind of high ground, in this case after the air has flowed over the Snowdonia Mountains. The clouds appear almost stationary, continuously forming and dissipating and may last several hours. To the NW frontal cloud was sliding past to the NE; there was rain over Northern Ireland and Scotland (there are more photographs of the cloud formations seen on the day). By noon the lee-waves had gone the sky becoming overcast. Then, there was more showery slight rain, but by the end of the afternoon had brightened again. The night was mostly cloudy. [Rain 0.2 mm; Max 8.6C; Min 2.6C; Grass 2.0C]

The rainfall accumulated at the end of November can be compared with the top 10 wettest years in this graphic. The race was on for 2004 to beat 2000 (that had 1483.9 mm) for the infamous record of the wettest year in Llansadwrn since records began in 1928. By the end of November the rainfall for the month had reached 92.7 mm, the wettest November since 2000. The total for the year stood at 1193 mm, 6th wettest but seemed unlikely, with just December to follow, to reach the year 2000 total.

December 2004