Llansadwrn (Anglesey) Diary 2018 21st year

             

• January
• February
• March
• April
• May
• June

Times are GMT (UTC, Z). Observations at this station [ ] are 24-h 09-09 GMT, some others { } occasionally refer to other 24-h periods, extremes (first indications) are given in bold and are usually 21-21 GMT. When averages are referred to (.) compares with the last decade and [.] with the new 30-y climatological average [1981 - 2010]. All data are subject to verification and amendment.

January 2018

January 1 - a fine and bright morning with moderate to good visibility. There were snow patches as low as 2250 ft on the Carneddau Mountains and there was a fresh sprinkling of snow above 2750 ft. Overnight an air minimum of 3.8C with a touch of ground frost. Mistle thrushes were making chirring noises in the trees, but there has been little singing from them so far this winter, A fresher feel to the 5.2C temperature in a light SW'ly breeze. A few sunny spells then turning cloudier during the middle of the day with some glimpses again later in the afternoon [Max 7.6C Min 3.8C Grass -0.2C Rain 8.8 mm]. The 2nd began overcast with a blustery force 4/5 SSW'ly wind. With the soil near saturation point any rain results in some standing water around the garden and it was trickling in one or two places. Visibility was moderate in slight rain that began to ease soon after 09 GMT. It was 6.8C this morning after a ground frost of -1.2C, but there was no frost to be seen. It was very dull, but there were some brighter spells with odd glimpses of sunshine later. Low 962 mb S Denmark Strait giving warm sector air with a following cold front and triple point S Ireland. Atlantic-low 995 mb was W of Brest, France. With very cold weather in N America the jetstream was set up to deliver some stormy weather to our parts. Becoming windy with named storm Eleanor approaching. Pressure 1001 mb had been falling quickly reaching 990 mb at 1800 GMT. With the wind gusting to 43 mph at Gorwel Heights the temperature rose to 10.7C at 1130 GMT while at Gorddinog AWS, with the wind gusting again at 43 mph, the temperature rose to 11.7C at 2020 GMT and here 10.6C with gusts of 37 mph at the same time. Rainfall 09-09 GMT today was 14.0 mm, Mona had 14.8 mm and Capel Curig 40.0 mm [Max 10.6C Min 3.1C Grass -1.2C rain 14.0 mm]. Windy overnight and still blowing on the 3rd at 0900 GMT force 6 where exposed to the WSW'ly the leafless trees still affording a good deal of shelter in the garden. There was precipitation in sight across the mountains where there were flurries around the summits. Bright at times with glimpses of sunshine during the day. At Ny Alesund the huskies would be enjoying fresh 9 cm of snow and a maximum of -10.2C after a minimum of -15.4C. At the Botanic garden in Tromso, Norway, the plants would be tucked up under deep snow, two stations nearby reporting 39 and 70 cm. When I visited there twice, in the summertime, I was impressed to see the 1 m high snow depth marker; I was informed it was necessary and often got covered. Here, no such snow cover for our garden alpines which struggle in our warm wet conditions [Max 9.5C Min 5.7C Grass 3.5C Rain 2.5 mm]. The 4th a cold front passed over from 0300 GMT, small hail at 0430 GMT, the minimum dipping to 3.8C then recovering rapidly and the morning began dull, mild and breezy; at 0900 GMT it was 9.3C with 96% relative humidity. Poor visibility with spots of rain on the force 5 SSW'ly. At Gorwel Heights the minimum was 4.4C and this rose to 10.7C at 0830 GMT and at Gorddinog AWS 10.6C at 0908 GMT. Pressure was falling rapidly to 984.3 mb at 0942 GMT then rising again to 997 mb by midnight. Low 981 was over Shannon at 06 GMT and the Isle of Man 982 mb at noon with Eleanor now well to the E 977 mb. A few glimpses of sunshine, otherwise mostly cloudy and quite a dull day [Max 9.6C Min 3.8C Grass 3.5C Pptn 1.7C]. The 5th was a brighter day, and made even brighter by the appearance of the first fully open snow drops, in clear visibility fresh snow was seen lying above 2250 ft on the Snowdonia Mountains, mostly on the NW flank of Carnedd Dafydd. Snowdrops had been showing a 'bit of white' for a few days being reluctant to open, today opening two days earlier than the median date of appearance in recent years [Max 7.0C Min 1.6C Grass -0.7C rain 0.4 mm].

On a visit to the sand dunes at Aberffraw on the 5th several of the dune slacks were flooded with water after recent heavy rains. This is not unusual at this time of year, it has been both drier and wetter in recent years. Over 100 cattle including some Murray Greys were grazing the large dune slack done to maintain, and improve the structure of the ecosystem and diversity of plant species . Recent named storms had not damaged the seaward dune system ; there was a little cutting back of sand at the southern end of the bay at recent spring tides .

The cooler weather continued on the 6th with showers in the morning that were giving a dusting of snow on the Snowdonia summits where it was -4C with a wind chill of -14C. Not as cold here at 0900 GMT 4.4C in an ongoing slight shower of rain with very little chance of any ice precipitation according to my rule of thumb calculation. Recent heavy rain and low evaporation has turned some field gateways in Llansadwrn to liquid mud (below left) with tractors making 2 ft deep ruts. Brightening up with glimpses of sunshine in an ENE'ly breeze this dying out in the evening as the sky cleared [Max 5.4C Min 1.6C Grass -2.0C Rain 0.1 mm]. A cold night and an almost clear sky on the morning of the 7th when visibility was excellent. Very fine with a cold ENE'ly breeze, sunny; snow lying at 2500 ft on the slopes of the Carneddau with a little cloud around the summit of C. Llewelyn. Pressure 1031 mb was rising with high 1033 mb centred S Scotland. A nice sunny day, Valley 6.6h [Max 4.3C Min 1.9C Grass -1.0C Rain nil]. Another cold night with air (-0.7C) and grass (-7.2C) frost with the ground frozen and here was ice on exposed water on the morning of the 8th when almost calm with chimney smoke drifting from the NE. The sun rose above the mountains at 0855 GMT. There was little white frost to be seen on vegetation as the air was fairly dry. The temperature was 0.4C here and -6C on Snowdon with a wind chill of -18C. In Llanfairfechan conditions were quite different; there was a strong wind blowing off the mountains, known locally as the Carmarnaint wind, or the wild Carmarnaint Gwyllt Carmarnaint, with gusts of 45 mph recorded at Gorwel Heights and 54 mph at Gorddinog. David Lee said the mean speed has been the highest for a long time reaching over 32 mph for a 10 min mean and around 37 mph for a 2 min mean. The gusts peaked at 08:56 GMT. Weather radiosonde ascents from Nottingham and Herstmonceaux both gave a strong inversion below 3000 ft and 40 mph in the inversion. A lorry overturned on the A55 at Abergwyngregyn and police closed the carriageway for 2 hours to allow recovery work to be carried out. Pressure was 1024 mb with high 1037 mb stretching to Estonia; frontal systems in the NW seemed poised to encroach later. It was cold in the north of Britain under clear skies (Aberdaron sunniest with 6.9h), but warmer in the south under cover of cloud [Max 6.2C Min -0.7C Grass -7.2C Rain nil].

A bright start on the 9th with some fog lingering in low lying areas. Air minimum of -1.4C and -5.3C on the grass with more frost on the grass and a little hoar on some plants and the rims of the copper raingauges slightly rimed. The ground was frozen with the 6 cm soil thermometer reading 0.1C. Some plants including purple sprouting broccoli and leeks were slightly temporarily wilted, physiological drought. The heater was not on in the black AWS TBR and this was particularly frosty and when this melted about 1100 GMT the bucket tipped; turgor returned to the wilted plants by afternoon. Pressure 1005 mb continued to fall with high now 1040 E Baltic region and low 949 SW Iceland with a cold front W of Ireland. Turning cloudier with frontal cloud encroaching across the Irish Sea. The daytime maximum was about 7.5C, the temperature rose later reaching 9.0C just before midnight and was the day's maximum [Mona Min -4.4C Capel Curig -2.9C] [Max 9.0C Min -1.4C Grass -5.3C Pptn 0.2 mm].

After a mild night with rain on the mountains not helping the meagre snow cover the 10th was a fine sunny day after a spectacular sunrise between Carnedd Llewelyn and C. Dafydd. There was fog in some low lying parts and to the E and S and here just 3 oktas mainly cumulus clouds with some long expanding contrails over Red Wharf Bay. Mostly sunny with little or no wind. I saw two vegetation fires had been set on the lower slopes of the mountains, they were small and did not burn for long. Very little snow, just a few small snow patches high on the summits (Yeovilton 7.1h and 12.3C, Aberporth 6.1h, Valley 5.7h) [Max 9.3C Min -0.1C Grass -2.5C trace]. A dull damp and cool day on the 11th with overcast sky and good, but misty visibility. Another calm morning with even the chimney smoke rising vertically. Pressure 1021 mb was rising with complex low-pressure over Britain with a ridge to the W extended from high 1031 mb W of Iberia. Sunless day [Max 5.5C Min 2.9C Grass -1.8C trace]. There was shallow fog on the fields in the night, and on the morning of the 12th it was fine, bright and frosty with extensive white frost on the fields, with some hoar and rime (rare here in recent years). Dense fog in central England today. Pressure was steady on 1024 mb rising to 1026 mb in the evening with the jetstream's flow disrupted (blocked) by Scandinavian/ Baltic high-pressure 1041 mb, it's not expected to last. An air from the NNW indicated by smoke drift. Sunny under some cirrus clouds, cloudier later. Sunniest was in Bala with 2.6h [Max 7.2C Min -0,.7C Grass -5.5C Pptn nil]. There was a red sky over the Carneddau and Conwy this morning the 13th, not a good sign. Breezy (30 mph) in Llanfairfechan overnight. The sky at 0900 GMT was overcast and there was a light SE'ly breeze. Pressure was 1014 mb with a low 1000 mb SW Iceland having an associated fronts lying N-S over Britain. Fine at first, but dull. Light rain from noon, heavy over the mountains with [18.6 mm] falling in Capel Curig and more in the SW [30.4 mm] in Camborne and [28.2 mm] in Culdrose. Rhyl had just [0.2 mm]. Sunless day [Max 7.3C Min 0.7C Grass -2.5C Rain 2.0 mm]. A brighter start on the 14th, but it soon became cloudier and windy later later with rain. Pressure was 1017 mb and although the jetstream was still blocked by Baltic high 1043 mb, low 951 mb Iceland had significant fronts to the NW and occluded front lingering N-S over Britain. Pressure began to fall from noon and more quickly during the evening with strengthening wind . There was light to moderate rain from 2030 GMT [Capel Curig 33.2 mm, Shap 33.8 mm, Rhyl 2.2 mm] [Max 9.1C Min 5.1C Rain 23.2 mm]. Rain continued after midnight on the 15th becoming moderate to heavy by 0130 GMT with the reaching temperature 8.9C at 0310 GMT; windy Gorwel Heights gust 46 mph 0054 GMT. By morning 23.2 mm of rain had accumulated. There was a cold front and wave over the Irish Sea slipping SE to central England; pressure was 991.8 mb and remained low till evening when it began to fall some more. A minor clearance began at 0930 GMT and the afternoon had some sunny spells. The wind had moderated, but strengthened again. There was showery precipitation before midnight with small hail [Capel Curig 13.0 mm Sennybridge 17.2 mm Lake Vyrnwy 19.6 mm Rhyl 2.6 mm] [Max 8.9C Min 5.3C Pptn 1.0 mm].

The first 15-d of the month had 48.5 mm precipitation (42%) & [48%] of the monthly averages, largely due to the 23.2 mm on the 14th, while the mean temperature 5.0C was (-0.4) & [-0.1] of averages.

The 16th began brightly with a cool WSW'ly breeze and a temperature of 3.2C at 0900 GMT. Moderate to good visibility with convective cumulus clouds in the vicinity, a cumulonimbus was spotted at 0945 GMT. Pressure 993 mb was rising with low 974 mb S Norway and a cold front over Brittany. With low 951 mb E Iceland we were in a strong W'ly shower packed airflow. Slight showers of wet soft hail (h3), heaviest at 1305 GMT [Max 4.8C Min 3.2C Grass -0.2C Pptn 1.4 mm]. Similar The snowdrops are much better developed than when they first appeared on the 17th, strong W'ly wind with convective clouds again in the vicinity. There were a few patches of the soft hail or wet snow pellets, from yesterday on the ground at 0900 GMT. Pressure 1005 mb was rising quickly, there was complex low-pressure in the region of Iceland and high 1037 mb Azores and 1028 mb N Africa. The Irish storm was low 988 mb W Shannon at 1800 GMT. Becoming bright with some sunny spells, the strong near gale-force WNW'ly in the afternoon. Wet and windy in the evening to midnight; moderate to heavy rain and in warm sector air from 20 GMT the temperature rose from 4C to the day's maximum of 9.1C at midnight; Gorwel Heights 9.4C Gorddinog AWS 10.2C [Max 9.1C Min 1.7C Grass -1.2C Pptn 12.8 mm]. Fine after midnight with the temperature falling back to 3.1C by 0900 GMT the morning of the 19th; fine after recent slight showers of small hail, but feeling raw in the moderate WSW'ly wind. Pressure steady on 1007 mb with low 989 mb N of Scotland and high 1032 mb Azores with W'ly flow. Yesterday's storm now 990 mb SE Baltic/ Germany where there had been very strong winds, property damage and loss of life. Further showers here through the day, with 2-3 mm ice pellets at 1400 GMT [Max 4.5C Min 1.7C Grass -2.4C Pptn 2.2 mm].

The 20th began overcast and wet with pressure down to 999 mb here with frontal-waves 998 mb Severn estuary and 993 mb W of Ireland. Raining at 0900 GMT with the temperature on 2.7C with a 30% chance of ice precipitation; soil saturated with standing water and trickles of field runoff in places. It was cold enough to have snow falling on the mountains as low as 1000 ft at Ogwen and the A5 during the morning, here we had continuous slight rain [Max 4.3C Min 2.4C Grass -0.5C Pptn 9.7 mm]. Another miserable day on the 21st with rain since 0230 GMT. Very dull and very wet, moderate rain at 0900 GMT soil saturated with standing water and runoff trickles. Pressure 1007 mb falling with low 967 mb S Denmark Strait and W of Rockall. Slow-moving fronts were lying NW/SW of Britain and resulted in a sunless day. A dark tailed red squirrel came for lunch at the bird peanut feeder; was stranger, did not know about the squirrel feeder. Low cloud/ fog for several hours in the afternoon as the temperature rose to 10.0C at 1534 GMT. By 2200 GMT the temperature was 7C and it remained similar through the night [Max 10.0C 0.3C Grass -4.1C Rain 8.1 mm]. After a mild night the 22nd began mostly cloudy with a light WSW'ly breeze. Very damp in light showery rain, muddy and soggy ground, but no standing water today. Pressure 1010 mb was rising with low 968 mb SE Greenland with a trough to N of Scotland 989 mb. There was a weak ridge of high-pressure from high 1033 mb W of Iberia towards the Celtic Sea. Signs of clearance earlier, but still cloudy at noon. The lavender blue sweetly scented Algerian winter Iris (right) had been flowering well in the garden this winter. It took about 10 years for the plant to establish itself and produce flowers which usually begin in December. The narrow green leaves grow up to 30 cm in a tussock, the flowers are 6 - 8 cm wide. Native from north Africa to south-west Asia, but can be found in Greece. Here in winter slugs can be a problem felling the flowers at the base, so we pick them in bud before the slugs find them. There had been reports of cattle egrets seen at Pont Marquis went there in the afternoon and the marsh area and pool at Malltraeth, but saw none. Did see more than a 100 lapwings and 30 curlews over the marsh at high tide [Max 10.6 Min 3.2C Grass -4.1C Rain 1.3 mm]

Another overcast, dull and wet day on the 23rd, poor visibility in slight drizzle and rain in the morning. Ground saturated with some standing water in places, rather unpleasant [Tulloch Bridge 51.4 mm Capel Curig 34.2 mm] [Max 10.6 Min 6.6 Rain 9.0 mm]. Pressure had fallen to 995.5 mb at 0449 GMT on the 24th and there were strong gusts of wind here 44 mph 0510 GMT, 45 mph at Gorddinog at 0409 GMT and earlier at Gorwel Heights 53 mph 0143 GMT. Low 959 mb off the Western Isles, named Georgina by Met Éireann. High gust were recorded including at Great Dunn Fell 112 mph; S. Uist 85 mph, Capel Curig 83 mph, Mona 75 mph; and Valley 63 mph. The system had an associated cold front that passed over Anglesey at 0500 GMT resulting in the gusty wind, bursts of very heavy rain of up to 54 mm/h here and a 4 degree temperature fall. Still breezy at 0900 GMT with a fresh feel to the 6.9C temperature. Brighter in the afternoon with sunny spells as the wind moderated [Max 9.3 Min 6.2C Pptn 0.4 mm]. A brighter fresher morning on the 25th with a temperature of 5.1C at 0900 GMT. Low 987 mb was near the Western Isles and we were in a very showery airstream. Dark sky to the west with cumulonimbus in the vicinity. We had a slight shower of ice pellets 2-3 mm diameter at 0832 GMT. There were thunderstorms in S Snowdonia and particularly Pembrokeshire where damaging winds were reported [Max 6.8C Min 5.1C Rain 4.9 mm]. Overnight the sky had cleared and there was a slight ground frost with no precipitation since midnight.

At 0900 GMT on the 26th it was very fine with just 2 oktas cloud cover mostly obscuring the Snowdonia mountaintop with a few cumuli staring to form overhead. There was mist and fog in SE England with visibility down to 200 m reported in east Anglia. There was some sea fog also in Cardigan Bay and the Severn estuary. Cloud continued to form so that sunshine became minimal. In the west there was good mostly weak sunshine in the afternoon. At Aberffraw the cattle were grazing the large dune slack, the willow and middle dune hollows remain flooded, while on the beach there was some sea foam (chocolate mouse) washed up. The cause of this is obscure - the necessary surfactants could be due to breakdown of algal blooms perhaps unlikely this time of year; various organic materials washed down the Cefni in recent storms; or perhaps oil products. A thicker cloud mass encroached from the west later in the afternoon bringing the next lot of rain [Max 9.2C Min 3.7C Grass -0.5C Rain 1.7 mm]. The 27th began with leden sky, mist and rain and with poor visibility at a distance there was no discernible difference between cloud and ground; just one of those days. Pressure 1017 mb was falling slowly with low 971 mb S of Iceland with a trough to Scotland and frontal systems N Channel and Irish Sea; most of the UK was under an associated cloud mass. Dull, sunless, wet and windy all day with a blustery SSW'ly, but mild (Hawarden Max 13.6C Roches Point, Ireland 13.8C Shoreham Min -3.1C) [Max 11.0C Min 3.7C Rain 3.3 mm]. The temperature had been rising all night and on the morning of the 28th was 10.6C and 95% relative humidity Fine, with good visibility a bank of clouds was seen over the mountaintops and generally cloud was increasing. Pressure 1026 mb was rising with low 990 mb E Norwegian Sea moving SE. High 1039 mb was off Cap Finisterre and we were in a strong SW'ly airflow with a warm front along the western seaboard bringing warm tropical air from mid-Atlantic. Great spotted woodpeckers had began tentative drumming in the wood (Monks Wood Max 15.1C Rhyl 14.8C) [Max 11.8C Min 7.3C Rain 7.8 mm]. At midnight on the 29th with complex low-pressure 992 mb Norwegian Sea a cold front had encroached N Ireland and central Scotland. Gusty 39 mph wind at 0252 GMT and a burst of heavy rain 18 mm/h at 0710 GMT; 7.8 mm over past 24-h. A 0900 GMT with overcast sky, rain and mist with some standing water and runoff trickles. The temperature had fallen and was 7.3C (dewpoint 6.8C) 97% RH. Pressure 1023 mb was rising as the cold front moved across Anglesey. Fine with sunny spells in the afternoon, Valley 4.7h sunshine (Heathrow 13.5C Capel Curig 26.6 mm) [Max 8.5C Min 7.3C Rain 0.8 mm].

On a visit to the Newborough Forest on the 30th the panorama above shows the partially water-filled south pool in Newborough Forest, with gorse in bloom. The surface vegetation and soil on the adjacent former dune slack site left) with naturally regenerated successional deciduous birch trees, the habitat of rare plant species, was quite dry with the water table below 15 cm. Self-seeded pine trees that had grown here were removed 5 years ago (see Dairy 30 July 2013). The site is the habitat of rare plant species (see Dairy 4 September 2014). Ponies were eco grazing inside the fenced pool area. The photo right shows the marked effect of the grazing on the vegetation inside the enclosure compared with outside.

The 30th began fine and bright with good, slightly misty visibility. There is an absence of any significant snow patches on the N-facing slopes of the Carneddau, just some ice remnants around the summits over 3100 ft. Soon turning dull as cloud encroached from the W, but it kept dry. The panorama photograph above shows the water-filled south pool in Newborough Forest, gorse in bloom. The surface vegetation and soil on the adjacent former dune slack site (below left), the habitat of rare plant species, was quite dry with the water table below 15 cm. Ponies were eco grazing inside the fenced pool area. The photo right shows the marked effect of the grazing on the vegetation inside and outside the enclosure. During the evening the temperature began to rise, the wind strengthened and there was some rain [Max 7.2C Min 2.0C Rain 8.1 mm]. At midnight on the 31st the temperature was still rising reaching 7.2C, the maximum, at 0251 GMT ahead of cold fronts associated with low 981 mb N of Scotland. By 0900 GMT the temperature had fallen to 2.7C and there were fresh sprinklings of snow seen on the Carneddau summits and Snowdon, particularly the NW facing slopes of Garnedd Ugain. Fine, bright and fresher in the WSW'ly breeze. On passage of the cold front the temperature fell a modest 4.5C, there had a gusty wind of 28 mph at 0301 GMT and a burst of rain and small hail 12.6 mm/h at 0407 GMT. Bright in the afternoon then cloud encroached with some rain and hail spoiling any view of the rare super blue blood moon. When the cloud cleared just before midnight I did catch sight of the blue moon (above left) [Max 5.0C Min 2.7C Pptn 0.5 mm].

The month ended with a total rainfall of 121.8 mm (114%) & [120%] of averages, largest since 2016, ranking 34th in the 90-years of Llansadwrn records. The mean temperature 5.5C was lowest since 2015. Sunshine at RAF Valley was 59.5h.

February 2018

February 1 - a fine mostly cloudy morning with cumulus, cumulonimbus clouds and crepuscular rays in views towards the Snowdonia Mountains. There were a few unmelted ice pellets scattered on the grass with the grass minimum thermometer reading -0.6C. The soil could be described as soft and muddy, the temperature at 5 cm depth 3.0C and down at 100 cm it was 7.3C. Pressure 1007 mb was rising quickly with low 975 mb over the N North Sea and we had a showery NW'ly airflow. It was sheltered in the garden, but in the breeze the 4.0C felt cool. Mostly cloudy with a few glimpses of sunshine and missing the showers it kept dry [Max 6.9C Min 2.5C Rain nil]. Similar on the 2nd beginning bright with altocumulus and some towering cumuli to the S over the mountains, Fine and dry, the soil surface was soft but firming up for the first time for a while (Cardiff 9.7C) [Max 8.9C Min 4.1C Grass 1.7C Rain 4.2C]. The wind picked up after midnight with light to moderate rain on the 3rd and by 0900 GMT 4.2 mm had accumulated. The soil surface was then wet and muddy again. Mostly cloudy, but thinning overhead, with moderate visibility. Dull, with a raw feeling in the morning and frequent showers and brief sunny spells in the afternoon. Woodpeckers drumming in different parts of the woodland. Snow on the mountains over 2000 ft with some drifts in places on Snowdon. Showers in the evening, rain and wet snow pellets ]Max 6.3C Min 3.1C Pptn 1.2 mm]. A fine and bright morning on the 4th after a moderately red sky around 8 am. A little frost and ice on the ground and grass minimum thermometer (-1.1C) but soon melting in sunshine. Visibility very good to see snow lying at 2500 ft with some as low as 2000 ft on the Carneddau. The great spotted woodpeckers have now found very resonant branches upon which to drum, their answering responses sounding at different pitches. Fine and sunny in the afternoon and with clear sky temperatures falling quickly in the evening. After sunset there was a fine peach topped by azure blue glow in the west for about an hour after sunset [Max 6.8 Min 1.5C Pptn nil]. The coldest night for a while the air minimum down to -1.5C and on the grass -6.4C.

The temperature at 0900 GMT on the 5th was 0.6C (dewpoint -1.8C) 84% RH. Bare soil surface was frozen and there was ice on water, but grassy areas were soft. Mostly cloudy, crepuscular rays and glimpses of weak sunshine. Pressure was 1031 mb in a temporary ridge extended from Baltic high 1037 mb. Light N'ly airs, very good visibility slight haze, though cold a nice day. There was a widespread snow cover in France except coastal fringes [Max 3.5C Min -1.5C Pptn 2.0 mm].

On the 6th it was snowing at 0900 GMT with 2 cm of lying snow. There was moderate snowfall on the Snowdonia Mountains. Snow was widespread on Anglesey except the coastal fringe and was absent in Beaumaris petering out at the top of Red Hill. Visibility was poor at first, but improved when the snow turned to sleet mid-morning before ceasing. The afternoon was bright with a glimpse of sunshine [Max 4.7C Min -0.6C Pptn 3.1 mm]. Snow and snow pellet showers again on the morning of the 7th with fresh snow lying at the weather station. Here there had been falls of snow pellets on top of snow, elsewhere including near Four Crosses precipitation appeared all snow. At the 'rush hour' although the roads had been treated in the early hours the precipitation caused for tricky driving conditions and several 'collisions' were reported; several schools had been closed as a precaution. There was ice precipitation at sea level along the banks of the Menai Strait including at Porthaethwy (Menai Bridge) and Y Felinheli. None, however, was seen on the beach at Rhosneiger. At 0900 GMT the temperature was -0.5C (dewpoint -1.5C) and the pressure 1023 mb was rising in a ridge from Azores high 1040 mb. Frontal systems Wales and west of England. Warm front over Ireland associated with low 955 mb E Greenland/ Denmark Strait encroaching the west. Bright with some sunshine in the afternoon with snow remnants thawing and this continued in the evening as the air temperature rose from 18 GMT in warmer air the temperature reaching 4C by midnight [Max 6.7C Min -0.9C Grass -4.8C Pptn 7.3 mm]. There was 'warm' rain (>5C rising) from 0300 GMT on the 8th and by morning when 7.3 mm had accumulated. At 0900 GMT the temperature was 6.6C (dewpoint 6.3C 98% RH. Raining moderately at first easing later to light and drizzle. Very wet, pools of standing water with runoff trickles from fields gathering in places and roadsides. Very wet again in the afternoon, moderate to heavy at times (up to 10 mm/h at 1530 GMT) with moderate fog. Rain eased later in the evening (Capel Curig 46.0 mm) [Max 8.4C Min -0.5C Grass -1.8C Pptn 19.1 mm].

The 9th began brightly with 5/8th cloud clearing after passage of a cold front that brought sleet and snow pellets around 0650 GMT. A fine morning, but very wet underfoot after the 19.1 mm of rainfall measures at 0900 GMT. Misty, but good visibility and it was feeling cold in the NW'ly breeze the air temperature 1.8C (dewpoint 1.2C) and RH 96%. Pressure 1011 mb was rising in a ridge from Azores high 1038 mb. Fine afternoon with clear views of the snow on the Carneddau Mountains with the snowline on 1500 ft and some seen as low as 450 ft [Max 6.8C Min 1.4C Grass -0.8C Pptn 11.7 mm]. It was overcast on the morning of the 10th with a moderate SSW'ly wind and light to moderate rain. There was moderate fog so visibility was bad. Pressure 1004 mb was falling rapidly with a warm front over the Irish Sea, associated with low 967 mb Iceland, and a frontal wave over Cardigan bay and another developing low W of Ireland. Pressure had fallen to 997 mb at 1800 when the low 990 mb was over Dublin, reaching its lowest here 991 mb about 2100 GMT. As the soil is completely saturated runoff water from fields made the roads very wet; a dreadful day altogether (Hawarden Max 12,4C Benson Min -6.5C Capel Curig 45.2 [46.3 mm] mm Kinloss 3.9h) [Max 9.3C Min 0.4C Grass -4.0C Pptn 8.7 mm]. A colder day on the 11th with flurries of ice precipitation including at various times snow grains (1010 GMT), snow pellets (vs) and snow flakes (incl. 15 GMT) all of little volume when melted. A bit brighter morning with our resident storm cock (Mistle thrush) singing nearby, the temperature 2,4C. The ground was soft and muddy underfoot, the standing water of yesterday drained away. Pressure 1002 mb was rising with low 976 mb now North Sea with the fronts translocated to France. There was a shower trough in the west and central England and the SE mostly sunny. Bright with some sunny spells in the afternoon (Shoreham 8.4C Loch Glascarnoch -4.5C) [Max 4.6C Min 2.3C Grass 0.2C Pptn 0.2 mm]. A bright and chilly morning on the 12th with a WNW'ly breeze with pressure steady on 1013 mb. No air frost, but ground frost of -4.2C enough to freeze the surface of water in the garden and slight white frost on grass and some roofs. Very fine and sunny day [Max 6.3C Min 0.3C Grass -4.2C Pptn 5.1 mm]. On the 13th a deep trough arriving at 07 GMT resulted in a temperature fall to 1.2C by 08 GMT and as rain turned to sleet here a fresh fall of snow on the mountains where it was lying at 450 ft. The temperature on Snowdon at 0900 GMT was -6C with a wind chill of -19C, here it had recovered to 2.8C and with a NNW'ly breeze. Pressure 994 mb was rising rapidly. There was light to moderate snow at Ogwen, Llandegai and Bethesda. Bright with sunny spells in the afternoon [Max 6.8C Min 1.2C Grass 0.0C Pptn 0.9 mm]. As the barometer 995 mb was falling again on the 14th S'ly winds were strong to gale-force in exposed places. Mostly cloudy with precipitation in sight at 0900 GMT when 4.1C. Spots of rain by 0920 GMT, blustery all day. High gusts of wind in Llanfairfechan at Gorwel Heights 54 mph and Gorddinog 52 mph. A portacabin was blown off a lorry on the A55 going E just before the Aber turnoff; the road was closed in the small hours next day to effect recovery (Bude 11.5C Topcliffe Min -7.6C Shap 21.6 mm Thomastown 3.3h) [Max 8.5C Min 0.3C Grass -4.3C Pptn 3.5 mm].

The first 14-d of the month had 67.0 mm precipitation (89%) & [85%] of the monthly averages, largely due to the 19.1 mm on the 9th, while the mean temperature 3.9C was (-1.6) & [-1.4] of averages. There had been 11 grass frosts and 7 days with ice precipitation.

A fine, but cool breezy morning on the 15th with a moderate to strong WSW'ly. There were towering cumulus clouds over the mountains where there were wintry showers on broken snow, lines of old drifts and patches frequent as low as 2500 ft. Some weak sunshine and moderate visibility with an inversion in the Menai Strait. Becoming less windy, mostly sunny in the S and E [Max 6.9C Min 3.5C Grass -0.3C Pptn 1.0 mm]. Some light rain and drizzle overnight then an early sky clearance on the morning of the 17th before cloud began to increase again at 0900 GMT. Pressure 1019 mb was rising and the temperature was a mild 5.1C; gnats were flying about the garden. As cloudy no frost developed overnight. Fine, with weak sunshine at first, visibility was just good in mist. It had been dry overnight in Llanfairfechan. Fine views of the mountain snow in the afternoon as visibility improved with the snowline at 2750 ft with remnants as low as 1800 ft in places [Max 9.4C Min 4.5C Grass 1.5C Rain 0.1 mm].

Mostly cloudy on the 18th, fine with very good visibility after a slight shower at 0400 GMT; there was a very light ESE'ly breeze. There were some lenticular clouds forming in the lee of the mountains and around the summits under a upper layer of altostratus. Pressure was steady on 1019 mb , fine with very good visibility here, but mist and fog formed in central England and S Scotland. A trough from low 964 mb just S of Greenland was approaching the W while pressure over the Continent was high 1029 mb over SW France. Kept fine into the afternoon. (N. Wyke 12.8C Aboyne Min -4.6C Islay 10.4 mm Manston 7.7h) [Max 9.5C Min 3.5C Grass -0.6C Rain 4.3 mm]. Overcast and mild overnight minimum temperature on the morning of the 19th read 4.9C and no ground frost. In fact the grass minimum thermometer read 5.5C with surface soil warm for the time of year, 7.1C at 5 cm depth. It was moderately foggy, very damp 98% RH and a temperature of 8.5C at 0900 GMT. Pressure 1019 mb was rising, we were in warm sector air with a warm front running down the spine of the UK, with a ridge from high 1027 mb W of Iberia. There was a cold front lurking W of Ireland associated with low 963 mb SW Iceland. Cleared up in the afternoon when bright (Cardiff 14.2C Baltasound Min 1.0C Harris Quidnish 10.0 mm Glasgow 3.7h) [Max 11.0C Min 4.9C Grass 5.5C Rain 0.7 mm].

A much better day on the 20th for doing things out of doors. Starting with the 9 o'clock obs it was pleasant at the instruments. Buzzards were in the vicinity calling out and soon appeared over the wood. The temperature 5.2C with a gentle NNE breeze and sunny. Visibility was moderate with some mist and there had been heavy dew on the grass with a touch of frost after earlier rain. The afternoon although a little cloudier was mostly sunny [Valley 8.6h sunniest] so able to do some tidying up work around the garden. The snowline on the mountains had retreated to mostly broken snow above 3100 ft with snow patches as low as 2000 ft on the Carneddau (Strathallen 12.0C Katesbridge Min -0.9C Dundrennan 8.9 mm Valley 8.7h) [Max 9.6C Min 4.1C Grass -0.4C Pptn trace]. Another reasonable day on the 21st with 6/8th cloud cover at 0900 GMT composed of high banded cirrus, cirrocumulus, cumulus and altocumulus clouds. Good to very good visibility slightly misty in the E. High 1032 mb was over Scotland with pressure here steady on 1029 mb. Somewhat cloudier in the afternoon, cloudier in the east [Max 7.1C Min 2.8C Grass -1.2C Pptn nil]. Similar on the 22nd with very little cloud around at 0900 GMT. Pressure was on 1025 mb with a ridge from S Norway to the Celtic Sea and south-westward Low 969 mb was SE Greenland with fronts S of Iceland to the W of Ireland. It was windy in NW Scotland. Enthusiastic studying of the models suggests possibility of some very cold weather developing with very cold E'ly winds. It's a while since we had 'pipe cracking' easterlies. Underfoot with little or no rain for a few days grassy areas were soft, but firming up after being sodden for a long time. With temperature on the grass down to -3.4C there was only very slight white frost, but much silver frost to be seen Another dry day, very fine and sunny (Scilly 8.6C Mona 7.2C Shap Min -5.4C Bude 9.3h Valley 3.3h) [Max 7.1C Min 1.2C Grass -3.4C Pptn nil]. A brief red sky early on the 23rd and turning cooler with the minimum temperature 1.9C and under mostly clear sky -7.0C on the grass. A slight white frost on grass with a little hoar had developed. A nice sunny day, some more work in the garden in the fine afternoon (Kinlochewe 8.1C Mona 7.1C S. Newington Min -7.1C Sennybridge -5.6C Yeovilton 9.4h Valley 8.7h) [Max 8.5C Min -1.9C Grass -7.0C Pptn nil]. Another fine and sunny morning on the 24th with just 2 oktas cloud cover, cirrus and cumulus. Visibility was moderate with smoke haze and there had been an overnight air frost -2.9C and -7.3C on the grass and with fairly dry air only slight white frost and silver frost. Soil was frozen hard, looking surface dry, and was down to 0.7C at 5 cm deep. Currently the air temperature -0.8C (dewpoint (-3.3C) Fine, sunny and colder (Pembrey Sands 8.9C Mona Min -5.5C Pentraeth -4.9C Valley -4.7C & 9.7h) [Max 6.7C Min -2.9C Grass -7.6C Pptn nil).

One of those quite remarkable February days, on the 25th, we can have here when the weather is fine. Hardly a cloud in the sky, which is a good start, and a gentle E'ly breeze. Very fine, with very good visibility. Pressure 1027 mb was rising with high 1052 mb central Norway/ Sweden. A stronger breeze off the mountain at Gorwel Heights 41 mph at 1030 GMT, but here little or no wind. In the increasing warmth in the garden what was that I heard? The buzzing of honeybees, and there they were massed in the sun on flowering heather on our rockery banks. With the temperature in this sheltered part about 10.8C with a probe in the shade within heather and 20.1C, or higher, in the sun, it was very pleasant indeed to sit and listen to and watch the bees. They were there for about 5 hours gathering pollen, until the sun became too low in the sky. The maximum 'official' screened air temperature was 9.1C not far off the UK highest on the day of 9.4C at Mona airfield, at Valley it was 9.1C. In comparison it was 20.5C in Spain and 16.4C in Madeira. Disturbingly the temperature in Ny Alesund in the Arctic was Max 4.4C and Min 0.4C, and Jan Mayan Max 3.0C Min 0.0C. There have also been reports of the temperature in parts of northern Greenland being 35 degrees above normal. This is not good and, if repeated and persistent, is likely to upset global circulation patterns. In contrast the temperature in Tromso, Norway, was near normal at Max -5.9C and Min -12.7C (Mona 9.4C Loch Glascarnoch Min -8.4C Baltasound 2.4 mm Valley 10.1h) [Max 9.1C Min -0.8 Grass -3.8C Pptn nil]. Another bright and sunny morning on the 26th, but colder, at 0900 GMT it was 0.4C (dewpoint -3.3) in a light strengthening ENE'ly breeze. Pressure 1034 mb was rising, the Scandinavian high 1049 mb near the North Cape Norway had a ridge over the UK to Cap Finisterre, Iberia. This was already drawing in colder air from Europe and expected to take colder Siberian air in the next few days. An air frost overnight of -1.8C and a hard ground frost -7.1C on the grass with very little signs of whiteness. Bare soil and grassy areas were hard underfoot with the temperature of soil at 5 cm deep down to 0.4C. Visibility was very good turning cloudier later. The air temperature had dipped to zero just after 1800 GMT (Aultbea Max 6.7C Usk 4.9C lo Max Lake Vyrnwy -1.3C Aviemore Min -6.0C Tredegar -5.4C Lerwick 9.3h Aberporth 6.7h) [Max 2.7C Min -1.8C Frost 7.0h Grass -7.1C Pptn 3.3 mm].

At midnight on the 27th the air temperature had fallen to -2.3C and soon after ice precipitation began to fall and the temperature to rise. There was snow settling by about 0530 GMT and by 0900 GMT there was an average depth of 3 cm of lying snow. The temperature was then 0.8C (dewpoint -0.1C) and the snow eased by about 0930 GMT. Flurries, including snow grains and snow pellets, continued through the morning into the afternoon between glimpses of sunshine, heaviest snow grains around 1530 GMT (Derrycornahoule 6.2C Usk 3.8C Wych Cross Min 2.5C Morpeth 8.4 mm Rhyl 3.8 mm Camborne 8.5h) [Max 1.9C Min -2.3C Frost 13.5h Pptn 0.3 mm]. Air frost overnight and the air temperature was -2.7C at 0900 GMT on the 28th with 16.8h of frost in the past 24h. Minima were lower in Llanfairfechan AWS -4.3 at Gorwel Heights and -4.2 at Gorddinog. On the grass -6.2C here with the soil frozen hard the temperature at 5 cm deep was 0.3C; there was ice on water baths in the garden. There was about a 70% cover of snow on the ground so it was a second day with lying snow. Very cold, with ice flurries and glimpses of sunshine. The temperature struggled up to a maximum of 0.5C for a few minutes around 1411 GMT and to 1.3C at Valley, but remained below zero in Llanfairfechan making it an ice day there. There were cumulonimbus and towering cumulus seen and there was a slight shower of snow at 1415 GMT (Katesbridge 1.7C Braemar lo max -5.3C Valley 1.3C Farnborough Min -11.7C & Bala -8.9C Ravensworth 6.8 mm Bude 9.5h Valley 8.1h) [Max 0.5C Min -3.4C Frost 16.8h Pptn trace].

The month ended with a total precipitation of 76.7 mm (102%) & [98%] of averages. The mean temperature 3.9C was (-1.6) & [-1.3] of averages. Sunshine at RAF Valley was 115.4h.

March 2018

March 1 - another cold day. Overnight minima air -5.1C and on the grass -6.7C. Flurries of ice precipitation mostly ice crystals and snow grains unusual to see so much of these types here. Pressure 1007 mb was falling as a low named Emma by the Portuguese Met moved northwards into cold air. The ground was frozen hard to below 5 cm, it was -0.5C at 5 cm deep and 0.4C at 10 cm deep. At 30 cm it was 1.3C and 6.1C at 100 cm deep. A very cold and raw day in strong to near gale force E'ly wind with the temperature not getting above zero, the maximum -1.6C occurring at 1550 GMT - a rare ice day for Llansadwrn, but it rose to -1.1C after midnight. Almost continuous ice precipitation of ice crystals and snow grains through the day which had the odd effect of plastering the ground, paving and other surfaces with a thin layer of white icing, of no measurable volume [Max -1.1C Min 5.1C Pptn trace]. The 2nd began with the E'ly strong to near gale force on the exposed side of the sheltering woodland. Very harsh conditions at the 0900 GMT obs. The temperature -1.0C (dewpoint -4.2C) with a serious wind chill factor. A lot of birds visiting the feeding stations again today that had to be re-supplied several times. Water was in great demand, this freezing within a short time and having to be replaced. Redwings were seen in adjacent fields as well as lapwings with one of two coming into the garden. A pied wagtail also appeared and hung around all day. Numbers of blackbirds increased as have starlings Less in the way of ice precipitation seen today [Max 0.3C Min -2.9C Grass -2.7c Pptn trace]. A bright, but still cold morning on the 3rd the temperature at 0900 GMT -0.1C (dewpoint -2.2C). There was some snow left in patches mostly on shady areas. Pressure was on 993 mb with a complex low 982 mb over the Severn estuary. Some sunny spells in the afternoon as the temperature rose to a more respectable 3.4C. An unusual prolonged shower of ice precipitation from 17 GMT consisting of ice crystals (h1), some very small soft grains (h3), and small snow flakes at times all of little volume; when inspected there were no marks left on the hailometer [Max 3.4C Min -1.3C Grass -1.7C Pptn trace]. Much warmer on the 4th with pressure steady on 987 mb with a slow-moving low 978 mb over the Celtic Sea. At 0900 GMT it was 2.5C the highest at this time for 6 mornings. There was a great thaw of snow at lower altitudes on the mountains with the snowline rising to 2750 ft, but there were remnants at low levels including Llansadwrn. Slight deposits of ice crystals were seen on the bare soil surface that was still frozen, but the temperature at 5 cm depth had risen to 0.3C. Plants suffering physiological drought in the garden, including snowdrops, daffodils, leeks and broccoli, looked a little more turgid, but many leaves of frost sensitive garden plants are damaged including surprisingly purple sprouting broccoli. There was a shower of rain at 0950 GMT followed by some sunny spells. The temperature reached a minimum of 1.6C at 20 GMT; fog developed before midnight with the temperature rising [Max 7.3C Min -0.1C Grass -2.6C Pptn 2.1 mm]. Fog continued after midnight on the 5th, but by morning it had cleared and at 0900 GMT visibility was very good. The jetstream was re-established well south over the Gibraltar Strait, with a complex area of low pressure northwards including the UK with a slow-moving centre 983 mb near Dublin. Here pressure was steady on 986 mb. Mostly cloudy with a spell of light to moderate rain from 1600 GMT to 2200 GMT (Ballypatrick Forest 30.2 mm) [Capel Curig 22.6 mm] [Max 8.6C Min 2.2C Rain 11.2 mm].

The 6th began dull and overcast with a temperature of 3.7C at 0900 GMT. There was a little fresh snowfall on the mountains above 2500 ft. Low 984 mb was over the Irish Sea, but pressure here 986 mb was rising. Soon becoming brighter with a glimpse of sunless, this was short lived with drizzle and slight rain setting in [Max 6.5C Min 3.4C Rain 1.1 mm]. A fine brighter day altogether on the 7th with a cool SW'ly breeze and weak sunshine. Pressure 992 mb was rising with low pressure 985 mb near the Western Isles. There was a buzzard calling and flying in the vicinity while a great spotted woodpecker was drumming in the wood. The afternoon was fine with some sunshine when a white cap of snow could be seen on Carnedd Llewelyn, Black Ladders and C. Dafydd [Max 8.6 Min 2.2C Pptn 9.3 mm]. On the 8th a band of light to moderate precipitation on an occluded front moved across North Wales off the Irish Sea. It began as rain then as the temperature dropped turned to snow with 4 cm lying on the ground at 0900 GMT. There was 3 mm of water in the copper raingauge and snow in the funnel was melted bringing the total up to 9.3 mm. The temperature at 03 GMT was 2C and when snowing it around 0.3C then rose to 0.6C at 0900 GMT. Moderate fog had developed over the snow as the cloud began to clear and the sun begin to shine. Soon very fine and sunny with the breeze picking up blowing the snow off picturesquely covered branches of nearby trees, but it had turned cloudier again by 1130 GMT. The temperature reached a maximum of 6.5C just before 1500 GMT when much of the snow had melted [Max 6.5C Min 0.3C Grass (in snow) -0.5C Pptn 9.3 mm]. A frosty morning on the 9th with the temperature on the grass down to -3.8C; the thermometer was iced and dew drops at the tips of leaves were frozen. It was misty over the frost and snow, visibility was just good enabling the snow lying at 1800 ft to be seen along with old drifts to low levels. Six oktas of cloud cover altocumulus with some lenticularis in the light SE'ly breeze and weak sunshine. Pressure was on 1002 mb with low 992 mb N Scotland and low 976 off cap Finisterre and a warm front over Brittany moving north. Pressure was high 1020 mb to the S over Tunisia and 1033 mb to the N over Svarlbard. By afternoon the cloud had increased and there was light rain from 1930 GMT that was moderate at times [Capel Curig 20.0 mm, Mona 13.0 mm Rhyl 4.6 mm] [Max 11.5C Min 0.6C Grass -3.8C Rain 14.8 mm].

Rain continued after midnight on the 10th and was moderate to heavy at times. Rainfall accumulated in the 24-h to 0900 GMT was 14.8 mm; Capel Curig reported 20.0 mm and Rhyl 4.8 mm. The sky was overcast with the cloud base low on the mountains with low level mist over the Menai Strait. Pressure was on 998 mb with Atlantic-low 966 mb S of Iceland and W of sea area FitzRoy. A warm front was tracking N over the UK introducing warm tropical air and it felt muggy after the cold Siberian air of recent days; the warm air and rain had thawed much of the snow at low levels. The air temperature was 11.3C (dewpoint 10.9C) 97% RH. The ground was very wet underfoot and there was standing water in places; the soil temperature at 5 cm deep had risen to 7.6C after being frozen on the 1st and 2nd of the month. A cold front was over the W coast of France and storms had been triggered off Iberia and SW Spain. Some showers and brighter spells through the day with a Föhn enhanced temperature at Gorddinog in Llanfairfechan amongst the highest in the UK today (Kew Gardens 15.3C Rhyl 15.0C) [Gorddinog AWS 15.6C Gorwel Heights 14.7C Capel Curig 13.4 mm] [Max 14.0C Min 2.9C Grass 0.1C Rain 2.1 mm]. The 11th began mostly cloudy with a light SSE'ly breeze with wavy altocumulus and cumulus clouds occasionally bright. Pressure was on 992 mb with low 972 mb off Brest at 0900 GMT. Fine with glimpses of sunshine in the morning, cloudier with slight rain in the afternoon (Wiggonholt 15.3C Trawsgoed 14.4C Slobdon Min -0.5C Harris Quidnish 17.6 mm Tiree 6.4h) [Max 12.3C Min 3.3C Grass -0.5C Rain 6.5 mm]. The 12th saw the jetstream established well to the S over the Gibraltar Strait with low 981 mb over the isle of Wight and an occluded front over North Wales. Overcast skies and an ENE'ly breeze, cooler again at 5.6C, light rain easing and moderate misty visibility. There was a ridge of high-pressure W of Ireland with complex lows S of Greenland while high-pressure was 1025 mb over Morocco and 1031 mb Russia/ Siberia. It was dull and wet with slight rain in the afternoon. There was a clearance from the W about 1600 GMT and a flash of sunshine then turning colder a reduction from the day's maximum 7.3C of 3.5 degrees as the sky cleared to the minimum 3.8C. At 1800 GMT pressure was with low 978 mb over the Wash and occluded front over the Irish Sea associated with low 973 mb S Iceland (Bournemouth 12.5C Tyndrum Min -2.5C Sheffield 28.6 mm Hawarden 18.0 mm Tiree 7.3h) [Max 7.3C Min 5.1C Rain 0.8 mm]. On the 13th pressure 1007 mb was rising and it was a fine morning with some sunshine breaking through the 8 oktas of altocumulus and cumulus clouds. Visibility was good, but misty and the temperature 5.2C with 97% RH. A weak ridge of high-pressure was crossing the UK from high 1024 mb N Africa while a complex low lay over the Atlantic to the NW. A fine, sunny and dry day, there were plenty of primroses in flower in the garden although there have been a few to be found all year. [Max 11.1C Min 3.8C Grass -1.5C Rain nil]. In contrast the 14th was an overcast day. Pressure 996 mb was falling quickly with low 966 mb off SW Ireland with a warm front over the Irish Sea. The cloud was thin and the morning was brighter at times, but sunless. Breezy in Llanfairfechan at Gorwel Heights where the wind was gusting 45 mph at 1249 GMT. Cloud had thickened by afternoon and there was slight drizzle and rain. Blackthorn was seen in flower in Bangor [Max 10.6C Min 4.4C Grass -0.6C Rain 2.6 mm].

After a spell of light rain the 15th began overcast and a tawny owl was hooting in the wood at 0900 GMT. The temperature was 7.4C and pressure 984 mb was rising. Cloud had started to lift by 0930 GMT and visibility was very good and clear. Snow patches could be seen at 2500 ft and the summits were still in cloud and had snow flurries. It was very fine and sunny in the afternoon the temperature reaching 15.1C at 1410 GMT in a Föhn enhanced SSE'ly breeze; many bees were seen gathering pollen on the heathers on the rockery banks (Porthmadog 15.9C Tyndrum 34.6 mm Libanus 22.2 mm) [Valley 14.1C 5.4h, Mona 14.6C Gorwel 13.8C] [Max 15.1C Min 6.8C Rain 11.0 mm].

The first 15-d of the month had 61.5 mm precipitation (797%) & [732%] of the monthly averages. The mean temperature was 5.1C on the cool side (-1.8) & [-1.9] of averages. There had been 4 air frosts and 6 grass frosts and 4 days with snow falling.

A thoroughly wet morning on the 16th and as the soil remains saturated much standing water around. At 0900 GMT 11.0 mm was measured when it was still raining. Pressure 995 mb was rising with large areas of low-pressure to the NW 980 mb SE Greenland while high 1036 mb was over N Scandinavia with tight isobars and strong winds over the North Sea. Models suggest that we will have another cold plunge at the weekend and a MetO yellow warning for strong gusty winds for tomorrow; and a yellow warning of more snow for S Wales received as writing. Not the dry quiet March we sometimes have in these parts. The temperature at 0900 GMT was falling on 6.8C, light to moderate rain with poor visibility. By afternoon it was brighter with some sunshine the temperature rising to 10.9C warm enough for some bees to forage on the heathers [Max 10.9C Min 6.7C Rain 7.6 mm]. Overnight the E'ly breeze strengthened and the air temperature dropped to 1.3C by the morning of the 17th when overcast and dull. There was some fine ice precipitation on the wind. At 0900 GMT pressure 1010.9 mb was rising with high 1041 mb over S Norway and a low 997 mb near Brest, France. Patches of snow were affecting parts of E and SE England where the air temperature was -3C. Here in the west the moderate to strong wind was roaring in the trees sunny spells developed. The temperature rose to 2.3C, but the wind chill made it feel a lot colder. Visibility was only moderate with slight ice precipitation in sight on the mountains. On Snowdon summit at 09 GMT the temperature was -7C with a wind chill of -18C. Frequent flurries of snow grains and snow and showers heaviest at 1350 GMT, the temperature struggled to reach 3.2C at 1500 GMT only to fall to below zero by 1800 GMT (Porthmadog 4.7C) [Max 3.2C Min 1.3C Grass 0.8C Pptn 0.9 mm]. Overnight the temperature continued to fall to a minimum of -1.7C at 0720 GMT on the 18th and there was snow falling in a very gusty wind giving at times blizzard-like conditions and forming rare snow devils over loose dry snow on the field adjacent to the weather station. At 0900 GMT in a temperature of -1.1C (dewpoint -2.1C) 2 cm of snow was lying with 4-7 cm at Gorwel Heights; mainly mountain roads were tricky and police advised care and only to venture out if absolutely necessary. A rolling road block was again necessary on the A55 at the tunnels to remove icicles that had formed. By 1250 GMT the air temperature had risen to just 0.1C, reached 0.2 at 1313 GMT then hovered there until late afternoon (1750 GMT) when it went below zero (Kinlochewe 6.7C Valley 1.8C Baltasound Min -6.2C Otterbourne WW 5.4 mm Cardiff 3.0 mm Lerwick 11.3h) [Max 1.1C Min -1.7C Grass -2.7C Pptn 0.1 mm].

. Another fairly cold night the wind somewhat moderated with an air minimum about -0.3C. A bright morning on the 19th with clouds diminishing and some sunshine developing. Remnants of snow were on the grass together with large (some 1 cm diam) ice drops formed when melting snow refroze rapidly last evening. At 0900 GMT the temperature was 1.1C (dewpoint -3.2C) and pressure 1021 mb rising. High 1030 mb was midway between Iceland and N Scotland while a complex of lows 995 mb were over France and Italy. In the wings over the Atlantic a frontal system was line up from S Greenland to Iberia. There was a fine view of the snow on the lower slopes of the Carneddau with the cloud starting to break crepuscular rays developed. A mostly sunny morning and afternoon. Weather in France this morning at 09 GMT St. Tropez 13C (RH 47%%); Le Luc 10C (45%); Phare de Chasiron W coast 7C (91%); Cognac 4C (94%); Pau SW 10C (66) [Max 6.5C Min -1.2C Grass -1.5C Pptn nil]. On the 20th a very fine morning after clear sky earlier not with cloud increasing, but still mostly sunny. There were remnants of the snow still to be seen edging field boundaries and on the mountains frequent old drifts above 450 ft. Pressure 1033 mb was rising within high Shannon 1033 mb, there was a cold front on the E coast of England Lincs and Kent. A somewhat warmer NW'ly flow was introduced here with a maximum of 8.9C, the cold plunge was heading S for France and Spain [Max 8.9C Min 0.5C Grass -3.5C Pptn nil]. No air frost again overnight although the temperature on the grass under clear sky was down to -6.3C on the morning of the 21st with slight white frost on the grass fields. Bright with weak sunshine, very good visibility, but with cloud encroaching from the N soon turning duller by 1030 GMT, but kept dry [Max 7.8C Min 0.2C Grass -6.3C Pptn nil for the 3rd day].

The 22nd was again fine and bright with some weak sunshine with moderately high cloud just touching some mountain summits. A frost-free night with an air minimum of 4.1C/ The temperature at 0900 GMT was 7.2C (dewpoint 4.9C) Cloud was increasing at 0900 GMT with pressure 1020 mb falling, but it was fine and bright at first turning duller later. The waving jetstream had temporarily moved N of Scotland there was a more S'ly dip over the Atlantic to the west. We were in warm sector air with fronts to the W, low 984 mb was over the Denmark Strait while a ridge of high-pressure 1032 mb lay N Spain and Iberia. There was light to moderate rain in the evening 18-20z [Max 8.4C Min 4.1C Grass 3.4C Pptn 4.5 mm]. A little rain before and after midnight on the 23rd when quite breezy 32 mph, and a fine, breezy morning. Visibility was moderate to good, with weak sunshine with sunny spells developing through the morning. The afternoon became dull with very slight drizzle in the evening [Max 9.3C Min 6.1C Rain 0.8 mm]. An overcast sky on the 24th, fine with good to very good visibility despite high 97% humidity, and there was a light NNE'ly breeze. No frost overnight and the temperature at 0900 GMT was 5.7C this rising to 9.3C at 1500 GMT when brightest. A dry day (Killowen 13.9C Pembrey Sands 10.8C Castlederg Min -3.7C Culdrose 15.8 mm Tiree 11.5h Aberdaron 8.7h) [Max 9.4C Min 4.0C Rain nil]. With clear sky developing overnight it was a frosty morning on the 25th with the grass minimum down to -4.1C, but no air frost the minimum air temperature 1.3C. There was much marine convection lying to the NW and convection over Ireland. Hardly a cloud to begin the morning then some convective cumuli developed over a first over the mountaintops and here by noon. A mostly sunny day, but we did catch a slight shower of rain in the afternoon. Cold weather in Scandinavia with the brackish water of the Gulf of Bothnia mostly frozen in the north (metopA satellite image above left) [Max 12.5C Min 1.3C Grass -4.1C Rain 0.2 mm].

Another fine frosty morning on the 26th, bright and sunny but cloud increasing at 0900 GMT. A temperature of 5.4C (dewpoint 5.4C) 94% RH. In the cloudier afternoon with some sunny spells the temperature rose to 11.2C. There was some light showery rain in the evening around 21 GMT. It was a fine day for the 700-year old Conwy Seed Fair, established by Royal Charter, when the narrow streets are taken over by stalls selling seeds, plants, honey and farmers' produce [Max 11.2C Min 1.7C Grass -3.2C Rain 6.0 mm]. After an early shower of rain on the 27th the sky was starting to clear with the sun breaking through. There was good misty visibility; the afternoon was mostly cloudy and dull, sunnier in the west of the island (Kew Gardens 15.9C Aviemore Min -3.1C West Freugh 18.6 mm Valley 5.8h) [Max 12.0C Min 6.3C Grass 0.2C Rain 1.0 mm]. A rather dull and wet morning on the 28th poor visibility with drizzle turning to slight showery rain. Pressure was on 1004 mb with a low 1001 mb over the English channel and another 979 mb between Iceland and N of Scotland. There was a robust shower front over the Irish Sea, a heavy shower of ice pellets was reported at Gorwel Heights at 1113 GMT. Clearing up to give a mostly sunny afternoon here when fresh snowfall was seen on the slopes of the Carnedd Llewelyn (right) as low as 2000 ft [Max 9.6C Min 2.6C Grass -1.5C Rain 1.2 mm]. A bright and sunny morning on the 29th, but pressure 998 mb was falling with a low 991 mb near Shannon with an occluded front over the Celtic Sea and marine convection to the W and SW. The afternoon was cloudier and there was showery rain 1730 to 1900 GMT [Max 8.7C Min 2.7C Grass -2.2C Rain 1.3 mm]. After a dry night with a touch of ground frost (-1.0C) it was a fine morning with a little sunshine at times. There was little or no wind and unusually it was calm at Valley at the 0850 METAR report while here the anemometer was turning in an ENE'ly breeze. Bright with glimpses of sunshine in the afternoon (Levens Hall 10.6C Dalwhinnie -2.3C Killowen 21.2 mm Tiree 9.4C) [Max 9.0C Min 2.4C Grass -1.0C Rain 0.2 mm]. An unpleasant morning on the 31st with slight rain on a cold NNE'ly breeze. Pressure 1002 mb was rising with a low 993 mb central England and an occluded front over the Irish Sea. It remained sunless, cold and damp with mostly drizzle and sometimes slight rain all day, but little volume was collected in the raingauges. There was more rain in Llanfairfechan and a wet day in the south (Chertsey Abbey 9.9C Baltasound Min -3.3C Okehampton 31.2 mm Lerwick 11.3h).

The month ended with a total precipitation of 87.5 mm (110%) & [103%] of averages. The mean temperature 5.2C was (-1.7) & [-1.7] of averages the third lowest in 40-years and tenth lowest back to 77-years in 1942. Sunshine at RAF Valley was 108.3h lowest since 2006 and ranked 30th on the Anglesey record since 1931.

It had been the third coolest March in the last 40-years. Cooler Marches were more common in the past, the diagram of anomalies back to 1942 (left) shows that there were another seven back to 1942, ten in all.

April 2018

April 1 - began fine and bright with a cold E'ly breeze. Some sunshine under 6 oktas of cirrus clouds and some expanded contrails. Some cumuli were developing over the mountains and the NE over Red Wharf Bay. Pressure was on 1014 mb in a col between Atlantic-low 992 mb S of Iceland and low 990 mb E Europe. Pressure was high 1021 mb over Greenland and 1040 mb over N Africa. A band of rain approaching from the SW, already over SW Ireland and Lands End was expected to turn to snow on high ground as it met colder air. The morning remained sunny while the afternoon partly sunny turned cloudier as thicker cloud encroached. There was drizzle and slight rain here, light to moderate in Llanfairfechan, from about 21 GMT [Gorwel Heights 41.6 mm] [Max 7.0C Min 1.4C Grass -1.5C Pptn 10.8 mm]. Overnight moderate to heavy rain in Llanfairfechan with 41.6 mm falling at Gorwel Heights, much of this fell as snow at higher altitudes with a good covering at Llyn Ogwen on the morning of the 2nd. Pressure 994 mb was falling with a low 988 mb steaming through St George's Channel. Precipitation rain and wet snow at altitude continued for a while before petering out and even on Snowdon, that has in recent days kept very icy, the temperature had risen to 5C by afternoon. Here the temperature rose to 10.6C just after 1500 GMT. A cool and wet beginning to the month the first two days having 21.8 mm of rain compared with 22.0 mm for the whole month last year [Max 10.6C Min 2.4C Rain 11.0]. A misty moisty morning again on the 3rd with recent rain just ceasing at 0900 GMT, Visibility was only moderate with rain continuing across the mountains in the distance. It was brighter, but there was a gusty SSE'ly wind. The afternoon turned fine and continuing breezy, warmer with some glimpses of sunshine [Max 12.5C Min 4.1 Rain 2.4 mm]. After showers of rain overnight the 4th began with a little N'ly or no wind at all. At 0900 GMT it was 9.5C, but there was a shower of rain then further light rain in the afternoon. Pressure was steady on 989 mb with a low 984 mb situated near Lands end. The temperature rose to 12.1C at 1046 GMT then began too fall reaching 6C at 15 GMT and 3.6C by 18 GMT to midnight [Max 12.1C Min Rain 1.6 mm].

Cooler again overnight and with some clear sky nearly another air frost the minimum just 0.3C, but a moderate ground frost -4.0C with slight white frost seen on fields early on the morning of the 5th. A bright sunny morning the frost soon gone here, but lingering on the lower slopes of the Carneddau where a sprinkling of fresh snow was as low as 1800 ft at 0900 GMT. The temperature had risen to 5.9C and this was to rise to 11.3C in the afternoon. Pressure 1015 mb was rising in a ridge from high 1022 mb over Spain and giving most of the UK a warm sunny day. At last a chiffchaff has arrived here having been seen on the Welsh western offshore islands a few days ago, it was heard singing and seen in a surviving elm tree that had just started to flower, 11 days later than last year which is the median date of arrival here in recent years. Not as late, however, as the latest dates which are 12 April 2001 and 10 April 2013, both late springs. Elms are one of those species that flower before the leaves emerge; most elm trees were destroyed in the Dutch Elm Disease outbreak of the 1970s. Also spotted today was the first peacock butterfly to emerge, photographed sunning itself on a warm path, 21 days later than last year when one was seen on the 15th March (Gravesend 13.5C Hawarden 11.7C Dalwhinnie Min -6.9C Sennybridge Min -3.5C Altnaharra 11.9h Lake Vyrnwy 9.5h) [Max 11.3C Min 0.3C Rain nil]. Another fine morning on the 6th, weak sunshine with 6 oktas of cloud cover and very good visibility. Pressure 1004 mb was falling and thicker cloud encroached later in the afternoon. There has been blackthorn in flower in Bangor since the 14th March. It is always later in Llansadwrn and the first to come out was not spotted until today, 35 days later than last year on the 2 March, and 15 days later than the median date of flowering in Llansadwrn in recent years ranking 5th. The latest date in my records since 1996 are the 16th April 2001 and 15th April 2013, the earliest was the 22nd February 2016. Blackthorn flowers come out before the leaves develop, hawthorn is in reverse flowering after the leaves that are only just appearing here, so it will be a while before we see the flowers (St James Park 17.3C Porthmadog 15.7C Altnaharra Min -1.4C Banogher Cough Hill 35.6C Herstmonceux 10.1h) [Max 14.7C Min 4.7C Rain 2.5 mm]. The 7th was an unpleasant day beginning with continuous slight rain with only moderate visibility. Similar in the afternoon although the precipitation was more drizzle than rain. Late afternoon the sky brightened from the west and there was some weak sunshine in the early evening (Gravesend 19.4C Kielder Castle 0.2C Liscombe 21.8 mm Camborne 7.1h Aberdaron 3.1h) [Max 9.0C Min 7.3C Rain 2.4 mm]. The 8th began fine and fairly bright with good visibility and continued that way into the afternoon, a dry day [Max 12.2C Min 5.3C Rain nil]. A very fine sunny day on the 9th after a frosty morning with heavy dew on the grass the minimum -1.0C. The temperature rose to 14.4C by 11 GMT. A sunny afternoon (Porthmadog 16.2C Camborne 10.4h Valley 8.7h) [Max 14.4C Min 4.1C Rain 0.9 mm]. In contrast the 10th was dull and overcast with slight rain and/ or drizzle most of the day. Pressure was 1003 mb with a large low 994 mb W of Brest, its influence extending from Scotland in the N to the Straits of Gibraltar in the S, with a warm front over the Irish Sea. Visibility in the drizzle and mist was at best moderate and by evening was very poor with moderate fog at times. Cool air from the N reached as far S as Morocco and N Africa. Weather was poor in France for the time of year [Max 8.6C Min 6.8C Rain 0.6 mm].

Pressure on the 11th was steady on 1009 mb and it was a dull morning here although brighter looking towards Conwy. There was a low over NE Spain and this brought unseasonable cool air and caused some very rough seas along the S coast of France. With a high 1032 mb over the E Baltic states we still had the cool E'ly airflow with very poor visibility. Brightening up in during the morning with some weak sunshine the temperature just got up to 10.45C at 1130 GMT before some thicker cloud encroached. Brighter again in the late afternoon and a little more sunshine (Wales: Porthmadog 14.0C Mona Min 5.4C St Athan 8.6 mm Valley 1.4h) [Max 10.2C Min 6.3C Rain nil]. A bright start on the 12th with poor visibility in moderate smoke and dust haze. There was weak sunshine at first with a maximum of 10.2C before turning cloudier with spots of slight rain setting in during the afternoon (Achnagart 16.8C Porthmadog 15.2C Lerwick 13.0h Aberdaron 2,.6h) [Max 10.2C Min 5.8C Rain 0.2 mm]. A miserable morning on the 13th with thick cloud, drizzle and very poor murky visibility. The temperature at 09 GMT was 7.0C with 96% RH. No improvement during the very dull sunless day that had low solar radiation. The daytime maximum was 8.1C at 1345 GMT (Milford Haven 13.7C TxLo Lake Vyrnwy 7.2C Baltasound Min -0.8C Sutton Bonington 18.4 mm Bude 3.2h) [Max 11.0C Min 5.7 Rain 0.7 mm]. Well we were due for a better day and the 14th turned out to be very nice. Beginning brighter the temperature had risen and was 10.8C at 0900 GMT and the sky was clearing slowly. Pressure was 1015 mb with low 974 mb S Iceland and W of Brest. A ridge to SE England from high 1024 mb N Italy. The wind backed SW to NE during the afternoon and we experienced a Föhn breeze the temperature rising to 16.0C at 1320 GMT (Northolt 19.5C Trawsgoed 17.9C Charlwood 11.3h Aberporth 10.1h) [Max 16.0C Min 6.9 Rain 0.2 mm]. It was too much to expect two nice days and the 15th was business as usual with overcast skies and slight rain or drizzle at times, but it was much milder with the temperature 14.6C above average despite lack of sunshine. A close call today according to spaceweather.com a 'Tunguska-class asteroid about the size of a football field flew through the Earth-Moon system. 2018 GE3 was discovered just the day before as it plunged inward from the asteroid belt' . The Tunguska impact of 30 June 1908, destroyed 2000 square kilometres of conifer forest in a sparsely populated region of the Central Siberian Plateau, had the energy of a large hydrogen bomb, but no meteorite crater associated with it has been positively identified. (Wales: Porthmadog 17.2C Aberdaron 2.6h) [Max 14.6C Min 8.8C Rain 1.3 mm].

The 16th began brightly with a strong S'ly wind whipping up the sea along western shore, it was very rough at Rhosneiger. Pressure here was on 1008 mb with a deep Atlantic-low 946 mb S of Greenland and W of lands End. Pressure was high 1032 mb over the Black Sea region. A mostly sunny day [Max 13.4C Min 8.2C Rain 3.1 mm]. There was showery rain after midnight on the 17th with 3.1 mm accumulated by 0900 GMT. Overcast sky and strong to gale force S'ly wind with slight rain on the wind. It was a beautiful day all over France with coast to coast sunshine, and models indicate the good weather was heading our way, I can't wait [Max 13.3C Min 10.0C rain 3.1 mm]. The 18th began with the same overcast sky, but the weather had improved in South Wales, the sky looked brighter in Llanfairfechan and and it soon dramatically improved here. A very fine sunny afternoon the temperature rising to 22.6C here and at Gorwel Heights with 22.8C AWS at David Lee's station at Gorddinog in Llanfairfechan. The first bluebell of the season was spotted in the wood today 2-weeks later than last year, 10-days later than the median date of recent years, but earlier than the latest date on the 26 April 2013. A fine evening with the temperature still 18.1C at 2100 GMT (St James Park 25.3C Porthmadog 22.6C) [Max 22.6C Min 10.4C rain nil]. Another nice day on the 19th, a little more cloud and not so much S in the wind direction so cooler the maximum a respectable 17.1C (St James Park 29.1C (Record) Cardiff 23.1C Eskdalemuir Min 3.7C Charterhall 13.6h Lake Vyrnwy 13.1h) [Max 17.1C Min 9.8C Rain nil]. Fog developed after midnight on the 20th, but by morning it had cleared and the sky almost clear of cloud with very good visibility. There had been heavy dew and fog deposition and a slight whitish pink dust was detected likely to be of Saharan origin along with some local greyish local dust. Another nice day and a fine and sunny evening (Frittenden 26.8C Tredegar 22.0C Mumbles (sea fog) 11.7C Leconfield 13.3h Lake Vyrnwy 12.7h) [Max 17.4C Min 7.6C Trace].

A rare morning on the 21st with no cloud that I could see, and very good visibility with just slight haziness. The MetO issued a yellow warning for thunder storms for North Wales from 4 pm, but it kept sunny here until evening when towering cumuli were seen over the mountains to the SE and the sky darkened and there were spots of dusty rain around 20 GMT. Storms did develop, but well to the E and moved up to Cumbria. Other larger storms developed N France and moved across to IoW, S England and the Midlands (Bude 24.9C Trawsgoed 24.7C Aboyne Min -2.6C St Catherine's Point 8.2 mm Aberdeen 13.2h Aberporth 12.2h) [Max 20.8C Min 6.6C Rain 0.3 mm]. On the 22nd there was a little rain from 07 GMT and at 0900 GMT there was slight rain and mist with moderate visibility. There was a slight deposit of pinkish white dust likely to be of Saharan origin. The morning was dull and breezy at times with a cold front passing over. There was some sunshine mid to late afternoon before cloud encroached again with some spots of rain (Gravesend 25.0C Usk 17.3C Otterbourne WW 26.6 mm Manston 12.0h Aberporth 5.7h) [Rain 0.1 mm]. The 23rd began dull and overcast with altostratus clouds and good to very good visibility somewhat hazy. Pressure was steady on 1014 mb with a low 989 mb over the Norwegian Sea and high 1020 SE France we had a SW'ly airflow. There was a glimpse of sunshine in the afternoon before cloud thickened and the wind began to strengthen. Our busy road was closed again today for repairs. This time it was resurfacing the junction on to the A5025 - I took the opportunity to walk its length top to bottom in the absence of traffic (Heathrow 16.7C Charlwood Min 3.8C Cluanie Inn 16.6 mm Shoeburyness 9.1h) [Max 12.0C Min 7.5C Rain 0.1 mm]. Another very dull and wet day on the 24th with slight rain from the off. The cloud level was low and visibility moderate with in mist and rain. Pressure 1012 mb was falling with low-pressure to the N 983 mb and high-pressure to the S with the jetstream set up to deliver more of the same in a SW'lt air flow. There was a frontal wave low over St George's Channel, not good news, and rain turned moderate to heavy at times in the afternoon giving us the wettest day of the month. A front passing over between 16 and 17 GMT reduced the temperature then we had 10 to 15 minutes of sunshine. The low reached Merseyside 1001 mb at 1800 GMT (Gravesend 18.5C Aboyne Min 3.5C Gogerddan 25.8 mm Tiree 10.3h Bala 0.4h) [Max 9.5C Min 7.4C Rain 15.8C]

The month ended with a rainfall total of 62.3 mm (80%) & [98%] of averages. The mean temperature 9.4C was (+0.4) & [+0.5] of averages highest since 2014 ranking 10 since 1979. Sunshine at RAF Valley was 140.6h lowest ranked 23rd lowest on the Anglesey record since 1931, but was highest since 2016.

May 2018

May 1 - began brightly with some sunshine and a line of convective clouds above the Snowdonia mountaintops. Pressure was 1007 mb in a declining ridge of high-pressure with a trough, from low 983 mb N of Iceland, with frontal cloud W of Ireland. Visibility that was poor to moderate in haze earlier had improved to good by 0900 GMT. The temperature had been as low as 3.6C in the early hours, but in sunshine was rising and reached the maximum of 10.8C at 0920 GMT, By 1230 GMT cloud had encroached and thickening spots of rain with spells of slight rain in the afternoon and evening [Max 10.8C Min 3.6C Rain 12.0 mm]. With strengthening wind a band of light to moderate rain arrived at midnight on the 2nd turning heavy (8 mm/h) at 0217 GMT. It was raining at 0900 GMT with 12.0 mm in the raingauge the temperature at the minimum 6.7C. Visibility in the rain was moderate, but improved as the rain ceased and some patches of blue sky appeared by 11 GMT as the front was clearing. Precipitation on the mountains turned to snow giving a sprinkling on Snowdon and several of the summits of the Carneddau including Carnedd Llewelyn and C. Dafydd. It is not unusual to see snow in May on the mountaintops, but there was none last year. Some sunshine for a while then cloudier again before evening (Thorney island 15.6C Loch Glascarnoch Min 3.0C Whitechurch Pemps 25.4 mm Camborne 11.2h) [Max 12.5C Min 6.7C Rain 1.5 mm]. On the 3rd yesterday's snow had disappeared, but there were still one or two albeit small snow patches surviving. A fine, but mostly cloudy morning with a cold feeling breeze, the sun occasionally looming through the cloud before it thickened too much. Pressure 1018 mb was rising in a ridge from high 1021 mb Cherbourg. The mass of cloud over the NW spoiled the day with slight showers midday and evening,the best of the sunshine was in SE England (Heathrow 18.1C Aboyne Min -2.0C Achnagart 10.6 mm Manston 12.4h) [Max 13.6C Min 5.3C Rain 0.4 mm].The temperature overnight had not fallen below the 9.5C at midnight on the 4th and with the sky clearing at 0900 GMT it had risen to 13.3C, Pressure 1022 mb continued to rise with a high 1025 mb Denmark and 1026 mb Azores. With a low 970 mb over the Denmark Strait, between Greenland and Iceland, we were experiencing a SW'ly airflow. There was some coastal fog patches earlier and cloud was not expected to clear here, but it did with sun shining on the mountains most of the day. Breezy at times, but pleasant as the temperature rose to 16.0C, and at Gorwel Heights 17.1C. A clear blue sky evening [Max 16.0C Min 8.7C Rainfall nil].

The 5th began fine and sunny and feeling warmer with the temperature at 0900 GMT 13.6C the maximum of the past 24-h. There was mist and fog around coasts and in the Menai Strait, but this cleared up here to give a nice sunny day, but not so on the coast where at RAF Valley recorded sunshine was zero. Pressure had risen to 1025 mb with a high 1029 mb over Denmark and with low-pressure 979 mb to the N it was windy in the NW of the UK. Pressure was also low over the Med 1009 mb Sardinia (Otterbourne WW 23.7C Tn Logan Bot Gdns 9.9C Achnagart Min 9.4 mm Morpeth 14.4h St Athan 14.0h) [Max 17.2C Min 7.8C Rain nil]. Fog developed after midnight on the 6th and was thick, visibility of 100 m at 0630 GMT, then began to clear so that at 0900 GMT visibility was good though slightly misty. Fog persisted for a while longer along the coast. The temperature was 13.9C with a RH of 98%. Pressure 1024 mb was falling with high 1029 mb over the Baltic while a frontal wave 1013 SW Ireland had an associated frontal band over Scotland. A sunny and warm day with the temperature rising to 20.7C (Heathrow 26.3C Santon Downham Min 2.0C Harris Quidnish 9.6 mm Boulmer 14.4h) [Max 20.7C Min 6.1C Rain nil]. Another sunny and warm day on the 7th with cirrus clouds developing overhead visibility was good, but hazy. The soil surface was dry with some small cracks; soil moisture determined today was 58% dm under grass, but had dropped to 29% dm on the bare met plot. Pressure continued to fall and was 1019 mb at 0900 GMT with a low 1013 mb off NW Ireland having a warm front over Scotland and a cold front SW Ireland (Northolt 28.7C Usk 25.7C Whitechurch Min 3.6C Tulloch Bridge 7.2 mm Shoeburyness 14.2 h Hawarden 13.4h) [Max 20.1C Min 8.4C Rain nil]. The 8th began mostly cloudy with some lee breaks in a S'ly breeze, but these did not last very long. With pressure on 1009 mb there was a low 988 mb SW Iceland with frontal cloud bands over the Irish Sea. There was some drizzle on western coasts and spots of rain here at 1015 GMT and with thickening cloud slight rain and mist at first in the afternoon before turning fine with some sunny spells later. A clear evening with a good sighting of Jupiter in the sky to the SSE (Gravesend 27.6C Lo Tx Valley 12.3C Kinbrace Min 4.3C Dundrennan 7.6 mm Mona 4.6 mm Odiham 12.6h Hawarden 7.3h) [Max 13.3C Min 8.3C Rain 1.6 mm]. A dull and rather cool day on the 9th with the sky overcast as a result of an occluded front over the Irish Sea [Max 11.5C Min 6.7C Rain 2.9 mm].

The 10th began with a fresh fell to the morning it being 9.3C at 0900 GMT. Pressure was on 1014 mb with a high 1025 mb off Iberia and a weak ridge extending to Wales at noon, while a low 973 mb SE Iceland had an associated cold front over East Anglia and France. The afternoon was fine with some sunshine, but breezy [Max 13.5C Min 5.2C Grass Min 2.0C Rain nil]. Disappointingly dull and breezy on the 11th. Pressure 1010 mb was falling with a low 978 off the Western isles of Scotland with a thick frontal cloud mass over Ireland and the Irish Sea. Showers of rain in the afternoon, heavy at 18 GMT (Gravesend 18.9C Aboyne Min -2.9C Banagher Caugh Hill 13.8 mm W'church 9.8 mm Manston 11.5h Aberporth 1.5h Valley 0.1h) [Max 14.7C Min 7.3C Rain 2.0 mm]. A brighter day on the 12th, but still on the cool side with cool air drawn from the north. Pressure 1014 mb was rising with low 986 mb off the Western Isles and high 1032 mb Azores; there was a small disturbance off Brest. Five oktas of a complex sky with a line of cumulus forming over the mountaintops by 10 GMT. The afternoon was fine with some sunshine, but kept rather cool (Hull 19.0C Katesbridge Min -1.7C Cambridgeniab 14.4 mm Stornoway 14.9h Aberdaron 10.9h Valley 10.1h) [Max 13.8C Min 5.4C Rain nil]. A fine morning on the 13th pressure 1015 mb was rising with hardly a cloud in the sky the day remaining sunny it was warmer and kept dry. The temperature rose from 12.8C at 0900 GMT to 16.7C at 1246 GMT [Max 16.7C Min 6.1C Rain nil]. Another very fine and sunny morning on the 14th with pressure 1023 mb rising in a ridge from high 1032 mb N of the Azores. The temperature at 0900 GMT was 12.7C (dewpoint 9.5C) and although the sky turned cloudier in the middle of the day it cleared later with sunshine into the evening [Max 17.0C Min 6.1C Grass Min 2.8C Rain nil]. On the 15th it was misty early in the day then began to clear with pressure steady on 1024 mb another mostly sunny day. The water was sparkling in Beaumaris with a good view across the Strait to Snowdonia. Sunny in the garden when I was surprised by what appeared to be a hornet buzzing around the flower border. I have seen these in North America and France, but not here. It turned out, however, to be a female broad-bodied chaser, a dragonfly, that in flight resembles a hornet. A first record for the garden (photo left). Frontal bands over Ireland moved across with a weak cold front passing over about 18 GMT producing slight rain between 19 and 20 GMT (Linton on Ouse 23.5C lo Max Gogerddan 14.2C Harris Quidnish 4.0 mm Whitechurch 0.4 mm Odiham 14.1h Hawarden 10.0h Valley 3.6h) [Max 18.9C Min 7.4C Rain 1.9 mm].

A mostly cloudy start to the 16th with a rather cool feeling strengthening NNE breeze. There followed slight intermittent drizzle with the sky becoming darker as cloud thickened. A dull afternoon at first then with the sky clearing later some sunshine before the end of the day (Glasgow 17.9C Pembrey Sands 16.2C Braemar Min -0.9C Shobdon 8.2 mm Rhyl 7.0 mm Prestwick 15.0h Valley 6.8h]

The first 16-days were relatively dry with 22.3 mm of rainfall (32%) & [36%] of the monthly average. Temperatures despite two warm days on the 6th & 7th remained on the cool side with the mean 11.0C [(-0.7%)] of average.

After a cool night the minimum 6.2C at 0159 GMT and 2.4C on the grass it was a fine morning on the 17th with 6 oktas cover of cirrus and cirrostratus resulting in mainly weak sunshine. Visibility was very good, almost clear, so that Bardsey was visible. We still had the cool NE'ly breeze, but with pressure steady on 1030 mb the day kept mostly sunny and dry [Max 15.3C Min 6.2C Grass 2.4C Rain nil]. With high pressure 1027 mb over Lincolnshire and pressure here steady on 1026 mb on the 18th the run of settled weather continued. Moisture on the grass (minimum 3.5C) was mainly of guttation, the exuding of moisture at the tips from the grass leaves, rather than condensation dew. This soon dried off in the warm sunshine it being 15.0C at 0900 GMT. Bands of frontal cloud were W of Ireland, but they did not encroach [Max 18.0C Min 7.4C Grass 3.5C Rain nil]. It was sunny everywhere on the 19th except the far NW of Scotland. It was one of those rare mornings here when I could not see any cloud in the sky and with a light SSE'ly breeze it was very pleasant. Visibility was very good with a slight haze and the temperature rose to 19.2C at 1212 GMT. On the west coast at Malltraeth Sands it was about 15C with a light breeze. With cirrostratus a solar halo was seen before cloud began to thicken from the west [Max 19.3C Min 6.7C Grass 3.5C Rain nil]. Moderately high thin cloud had encroached overnight so that on the 20th the day began bright, with a few breaks allowing glimpses of mostly weak sunshine. Pressure was on 1021 mb with low 972 mb Iceland with associated weak frontal bands encroaching the west with a wave over Rockall. Pressure was high 1028 mb over the Baltic. The temperature at 0900 GMT was 15.9C (dewpoint 10.2C) RH 69%. The day was mostly cloudy, but there was no rain. The soil surface in the garden was looking very dry. Soil moisture determined today was 48.4% dm under grass and 21.6% dm on the bare met plot. The permanent wilting percentage for the local soil is 15.2% dm (Sheffield 24.3C Sennybridge Min 1.9C Thomastown 12.4 mm Waddington 14.0C) [Max 17.1 Min 9.5C Rain nil].

A mostly cloudy morning on the 21st with thinning patches in the cloud sheet there was a little weak sunshine. Pressure was steady on 1018 mb with high 1020 mb E Baltic. There was a long frontal band in the W that stretched from the Norwegian Sea over Shetland and SW Ireland to the Atlantic off Iberia. Visibility was good, but smoke haze was increased through the day, some hazy sunshine in the afternoon (Pershore 24.5C Banagher Caugh Hill 28.0 mm Sheffield 14.8h Hawarden 13.0h Valley 6.8h) [Max 18.0C Min 9.7C Rain nil]. A nice day on the 22nd beginning sunny with a temperature of 13.2C at 0900 GMT that rose to 17.5C at 1422 GMT with 17.8C recorded at Gorwel Heights. Very warm in Porthmadog with a Föhn-enhanced 25.0C maximum. The seventh consecutive day here without measurable rainfall; a wet day in SE England (Porthmadog 25.0C Resallach Min -0.2C Manston 10.6 mm Rostherne 14.5h Aberdaron 13.1h Valley 12.5h( [Max 17.5C Min 7.2C Grass 5.9C Rain nil]. More of the same lovely weather on the 23rd starting with some cirrus clouds, hazy sunshine and a temperature of 14.1C at 0900 GMT. Pressure 1026 mb was rising with high 1029 mb over the Tay estuary. Sunny in the W with the E coast having haar off the N Sea. Very fine and sunny with a sea breeze in the afternoon. For the second day Porthmadog had the highest UK maximum temperature of 24.0C (Porthmadog 24.0C Gorddinog AWS 21.3C Morecambe 15.5h Valley 14.9h) [Max 18.4C Min 9.4C Grass 7.3C Rain nil]. Well we had had our ration of sunny weather and on the 24th the sky was mostly cloudy with thickening cloud, moderately high. Pressure was steady on 1023 mb with the Scandinavian high now 1032 mb over the Gulf of Bothnia. A showery trough had developed over S Britain and thundery lows were developing over Iberian and the Med and likely to head north. Dullest day here since the 11th (Bridgefoot 25.2C Hawarden 22.4C and 4.8h Lyneham 22.8 mm Morecambe 15.5h Valley 0.6h) [Max 16.6C Min 11.9C Rain 0.1 mm]. Again a cloudy, but continuing dry morning on the 25th with good visibility although with moderate smoke haze. Pressure was on 1021 mb with a thundery trough developed in the S moving N, at present it was best in the north-west. Fine, not cold, the temperature 14.0C and fairly bright with some weak sunshine at times. There were some spots of rain at times before a spell of slight to moderate rain in the afternoon, most since the 15th (Tyndrum 24.1C Porthmadog 20.6C Winterbourne (Mids) 24.1 mm Libanus 18.0 mm Tiree 14.7h Valley 3.0h) [Max 18.6C Min 11.6C Rain 2.0 mm]. Fine with a cool feeling NE'ly breeze on the 26th, mostly cloudy at 0900 GMT. Pressure was steady on 1023 mb with a high 1036 mb over the Norwegian Sea. A thundery low 1011 mb was over Bordeaux and weather in France was bad with thunderstorms and damaging hail. Not much in the way of sunshine here, a slight shower in the afternoon about 14 GMT [Bournemouth 27.3C Hawarden 23.0C Northolt 18.4 mm Stornoway 15.7h] [Max 18.5C Min 12.2C Rain 1.2 mm].

The 27th began with thunder, lightning and light rain showers encroaching from the SE from 07 GMT. The MetO had already issued a yellow be-prepared warning for S UK including SE Anglesey. At 0900 GMT the temperature was 16.1C (dewpoint 14.3C) RH 89% and there was a NE'ly breeze. A thundery low moving N from Bordeaux was off Brest 1010 mb and a thundery trough developed from the SE through the Midlands to Anglesey during the morning. Pressure was high 1033 mb central Norwegian coast. More thunder was heard accompanied by heavy rain from 1330 GMT with the electricity supply frequently interrupted as lightning struck nearby. Frequent passing storm cells into the evening continued through the afternoon. Rainfall was heaviest at 1644 GMT falling at a rate of 98 mm per hour, roof gutters were overflowing and there was standing water. Rainfall for the event totalled 36 mm here, over 9 h duration, and 46 mm at Gorwel Heights in Llanfairfechan. There was flooding in Birmingham where a man in his 80s died when his car was submerged, one street was flooded for the third time in a decade, the last time 2 years ago. Most rainfall fell at Winterbourne, near Edgbaston, 58 mm in 1-h, 81 mm in 12-h and 93.6 mm over 24-h. The monthly average for the W Midlands is 55 mm (St James Park 27.6C Hawarden 26.8C Winterbourne 93.6 mm Bala 54.0 mm Kirkwall 16.0h St Athan 7.7h) [Max 17.5C Min 12.3C Rain 34.8 mm].

The 28th proved to be a much better day beginning misty with poor visibility, but with hardly a cloud in the sky. Pressure 1020 mb was rising with a low 1015 mb in the SW Approaches. Frontal bands were W of Ireland associated with low 1003 mb NE Iceland. Pressure was high 1034 mb over Finland. A fine day with warm sunshine here (Valley 13.0h), sea fog affected some coasts in the W including Rhosneiger at first. The temperature rose here to the highest of the month 22.1C and 22.4C at Gorwel Heights (Cavendish 27.3C Hawarden 24.9C Braemar Min 3.5C High Wycombe 6.2 mm Kinloss 15.9h Aberdaron 13.9h) [Max 22.1C highest of the month Min 12.3C Rain nil]. A cloudless sky on the morning of the 29th with a light NE'ly breeze off the sea strengthening in the afternoon taking the edge of the temperature. Visibility was poor with thick haze developed, but in the E and SE of England mist and fog was persistent. Pressure was steady on 1020 mb with high 1031 mb over the Norwegian Sea. Thundery troughs were over the Dover Strait and Charente Maritime, France. Sunshine and temperatures were again best in the north-west (Achnagart 27.5C Porthmadog 26.7C Altnaharra Min 4.1C Frittenden 26.8 mm Stornoway 15.9h Valley 15.1h) [Max 20.2C Min 13.4C Rain nil]. A cloudier day on the 30th with 6 oktas cloud cover at 0900 GMT. The temperature was 15.1C (dewpoint 13.3C) and visibility was poor with smoke aerosols and dust. Pressure was on 1014 mb with occluded fronts associated with a thundery low 1009 mb Brest affecting S England from Cornwall to the Wash with current precipitation. Here not too bad a day with a maximum of 18.0C, warmer in Llanfairfechan Gorwel Heights 20.9C, but Porthmadog having 21.7C. Slight showers of rain came along in the evening (Achnagart 25.9C Kinbrace Min 3.9C Westonbirt 25.2 mm Loch Glascarnoch) [Max 18.0C Min 11.8C Rain 0.4 mm]. A warmer start to the 31st with a temperature of 17.4C at 0900 GMT (dewpoint 16.5) with relative humidity of 94%. Pressure was on 1015 mb with a low 1011 mb over the Celtic Sea introducing warm moist air. Troughs and unsettled weather continued in France with the Continent being particularly unsettled for the time of year with what seems like a succession of thunderstorms. Storms moved from France into the UK and were slow-moving in the Midlands, around Gloucester and and S Wales. Storms headed N, but were halted by the mountains dying out in S Snowdonia. No thunder was hear here although we did have moderate to heavy showers in the evening (Altnaharra 25.6C Porthmadog 24.7C Brize Norton 37.8 mm Scolton CP 10.6 mm Lerwick 13.8h Valley 4.1h) [Max 21.1C Min 13.7C highest of the month Rain 5.2 mm].

The month ended with a rainfall total of 66.0 mm (94%) & [106%] of averages, largest since 2015. The mean temperature 12.6C was (+1.0) & [+0.9] of averages lowest since 2016 ranking H8 since 1942, but H7 since 1979. Sunshine at RAF Valley was 231.6h, lowest since 2015, but lowest ranked H10 on the Anglesey record since 1931.

.

June 2018

June 1 - Overcast skies and warm 17.2C and humid 98% RH at 0900 GMT. Pressure was on 1017 mb with a low 1016 mb off NW Ireland with a thundery trough over the Irish Sea. Pressure was high 1026 mb over the eastern Baltic states. The sky darkened and thunder was heard from 1045 GMT. There was more thunder in the afternoon to the E of here from 1310 GMT. There were one or two bright spells with glimpses of sunshine, otherwise dull and damp. During the evening fog developed and became thick later before reducing just before and after midnight (Aboyne 26.8C Hawarden 24.8C Aboyne Min 8.0C range 18.8C Salsburgh, North Lanarkshire 29.8 mm Aberdeen 14.6h) [Max 20.2C Min 14.6C Rain 11.5 mm]. The 2nd began mostly cloudy with some weak sunshine through a thinning cloud sheet. Visibility was very poor in mist, but it was fairly warm the temperature at 0900 GMT was 14.7C RH 98%. Pressure was steady on 1018 mb with a low 1003 mb off SW Ireland and an associated frontal system over the Celtic sea. A bit brighter in the afternoon with a glimpse of sunshine when the temperature reached 19.6C and a dry day (Tyndrum 25.6C Katesbridge Min 7.6C Fylingdales 33.2 mm Hawarden 19.6 mm Exeter 13.4h) [Max 19.6C Min 13.2C Rain nil]. A brighter morning on the 3rd with a very light N'ly breeze setting in at 0900 GMT. Pressure 1021 mb was rising with a low 1016 mb East Anglia and convergence line on the Pennines. Low 1007 mb Celtic sea had remnant frontal cloud here and the SW. The strengthening breeze felt rather cool and the sky kept mostly cloudy at midday before becoming sunnier later in the afternoon and evening (St James Park 27.1 Usk 25.4C Sennybridge Min 11.9 Tyndrum 24.0 mm Bournemouth 15.2h Aberporth 14.9h) [Max 18.6C Min 11.0C Rain nil]. Another very fine and sunny day on the 4th with a light NE'ly breeze. Haze was thick and visibility moderate. Pressure was steady on 1018 mb with a low 1011 mb near Cap Finisterre. There was a shower trough over Scotland and the Borders with the weather is best in the west today. It was still very unsettled in France and the Med with ongoing thunderstorms (Porthmadog 26.6C Loftus Min 11.7C Tyndrum 5.0 mm Valley 15.2h) [Max 21.2C Min 11.4C Rain nil]. Continuing the fine weather on the 5th, but feeling a little fresher today the temperature at 0900 GMT 14.8C under thin moderately high cloud. Visibility remained poor in haze with mostly weak sunshine here. A weak cold front lying over the Isle of Man was responsible, but there was no precipitation here (Castlederg 23.2C Porthmadog 22.4C Millport 1.8 mm Stornoway 16.3C Valley 10.0h) [Max 17.6C Min 12.3C Rain nil]

A very fine and sunny day on the 6th, it was warmer being 17.3C at 0900 GMT. Visibility was only moderate in haze and there were 3 oktas cloud cover of mainly cirrus, cirrocumulus and contrails (Porthmadog 24.3C Loftus Min 11.3C Fylingdales 1.4 mm Prestwick 15.6h Hawarden 15.1h) [Max 19.4C Min 10.8C Rain nil]. On the 7th the sky was clear of any cloud and visibility was good with only slight haze. Some very small cumuli were seen over the mountains to the S at 1030 GMT. The weather was again best in the west with the Midlands and S England cloudier. Pressure was steady on 1018 mb in a slack area between high-pressure 1029 mb S Iceland and low-pressure over most of Europe and the Med (1014 mb Brest) [Max 19.5C Min 11.4C Rain nil]. A fine but mostly cloudy start on the 8th, there was thick haze again with moderate visibility. The breezy afternoon had some sunshine spells. The soil surface is very dry 44% dm under grass and on the bare met plot it was down to 15% dm with the top 2 cm with just 11% dm, see the graphs here. (Derrylincornahoule 23.8C Porthmadog 22.8C Pennerley 18.2 mm Tredegar 13.4 mm Kinloss 12.4h Aberdaron 7.0h) [Max 20.2C Min 12.3C rain nil]...

The first 15-days were dry with 17.5 mm of rainfall (21%) & [36%] of the monthly average. Temperatures were generally on the warmer side with the mean 15.5C [+1.6] of the 30-year average.

Dull with slight rain and drizzle from the start on the 16th with very poor visibility. The garden could do with some rain with 3.0 mm recorded at 0900 GMT, but it will take more to restore the water balance of the surface soil. Brighter and drier in the afternoon (Weybourne 21.6C Hawarden 20.2C Killylane 16.4 mm Capel Curig 14.0 mm Lerwick 12.3h) [Max 16.7C Min 9.4C Rain 2.5 mm]. Overcast and dull with low cloud on the Snowdonia Mountains on the 17th with a complex of frontal systems over Britain. Low 1005 had moved over the N Sea while low 985 mb S of Greenland was moving eastward. Pressure was high 1032 mb Azores and 1021 mb E Baltic (Scampton 20.2C Tulloch Bridge Min 2.0C Scolton CP 4.8 mm Kirkwall 6.1h Aberporth 2.5h) [Max 17.4C Min 11.4C Rain nil]. The 18th remained mostly cloudy but there was some weak sunshine at times. Low 977 mb was SE Iceland, but pressure 1017 mb was rising with high 1031 mb Azores to the Bay of Biscay. Moderate fog developed late in the evening (Heathrow 26.6C Salsburgh Min 8.9C Cassley 8.4 mm Shoeburyness 10.0h) [Max 16.7V Min 11.7C Rain 0.5 mm]. Another dull day in this part of Anglesey on the 19th which kept enveloped in cloud and mist in the afternoon. It was brighter in Beaumaris and on the mainland in Llanfairfechan, and NW Anglesey where there was some sunshine. Here, a sunless day (Writtle 25.6C Usk 22.0C Katesbridge Min 3.5C Derrylincornahoule 16.6 mm Lerwick 9.2h Hawarden 5.6h) [Max 17.0C Min 10.0C Rain 0.9 mm]. An Atlantic-high 1029 mb was S of Greenland, but it began very dull again on the 20th with mist, moderate visibility and slight drizzle. A cold front over Wales associated with low 1007 mb Tay Estuary resulted in a temperature fall of 4C between 10 and 15 GMT before recovering later becoming brighter with a little sunshine (Teddington 26.3C Dalwhinnie Min 6.6C Edinburgh Botanical Garden 33.6 mm Capel Curig 18.2 mm Lerwick 12.0h Aberdaron 6.5h) [Max 16.1C Min 13.9C Rain 0.5 mm]...

The 26th began very fine and warm the temperasture at 0900 GMT already 24.2C with 53% relative humidity. Just 3 oktas of cirrus and some contrails in the sky with very good visibility. Pressure was on 1026 mb with the high the UK high centred just off Aberdeen, Scotland. A mass of frontal cloud could be seen low in the sky to the NW off N ireland, but it did not encroach here. It was the warmest day of the month with 27.8C. Somewhat cloudy beginning the 27th, but warm. At 0900 GMT with pressure steady on 1026 mb the temperature was 24.1C with a relative humidity of 48% and here was a light ENE'ly breeze. Surface soil temperatures have been getting to dizzy heights. This morning the 5 cm deep thermometer on the bare met plot read 23.9C rising to 36.0C at 12 noon and 36.6C at 1400 GMT. The falling 34.0C at 1600 GMT, 27.0C at 1800 GMT and 23.6C at 2100 GMT. The next morning at 06 GMT it read 17.2C and at 0900 GMT it was 23.0C. Measurement of soil moisture (gravimetric method) indicate that in the top 2 cm of this soil there was no water. The minimum temperature of 16.1C was highest of the month, A large fire was affecting 7 sq miles of Saddleworth Moor on the Pennines near Stalybridge. The image (left) courtesy of the MODIS LANCE Team at NASA is of The Operational Land Imager on Landsat 8 acquired this natural-color image of the blazes around midday on June 27.(Porthmadog 31.9C Aboyne Min 4.3C Scarborough 0.2 mm Kinloss 16.2h Hawarden 15.7h) [Max 26.3C Min 16.1C Rain nil].

The month ended with a rainfall total of 21.9 mm (26%) & [32%] of averages, least since 1988. The mean temperature 16.0C was (+1.9) & [+2.1] of averages highest a the station since before 1979. Sunshine at RAF Valley was 291.8h, most on the Anglesey record since 1931.

Tweets by tywyddmon

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