The author: Dr. Donald Perkins FRMetS at the weather station but, sometimes, on expedition.

Llansadwrn (Anglesey)

Latest Diary 2020

21 plus 2

Logo: Llansadwrn Weather - Melin Llynnon, Ynys Môn

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    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 (provisional) maximum, minimum, rainfall and sunshine 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.


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    JANUARY EVENTS
    • Record 17.4C 'on this day' temperature recorded in Llanfairfechan on the 7th Chosen event.
    • Heavy rainfall in Llansadwrn and Snowdonia on the 11th Chosen event.
    • Storm Brendan hits hard on the 13th Chosen event.
    • Unusual persistent foggy weather with two rare fog at 0900 GMT observation on the 22nd Chosen event.
    • Winter was not quite over on the 28th Chosen event.
    FEBRUARY EVENTS
    • Very low humidity recorded. Föhn-enhanced temperatures made for a warm day and brought out the bees on the 7th Chosen event.
    • Storm Ciara brought heavy rain and gales on the 8th Chosen event.
    • Cold air from the Canadian Arctic brought a brief wintry spell on the 11th Chosen event.
    • Storm Dennis brought high winds and tidal surges around the coast on the 15th Chosen event.
    • Large 2 cm diameter hail shower at Gorwel Heights, Llanfairfechan on the 16th Chosen event.

    January 2020

    January 1 - a fine sunny morning to start the new year, cool overnight air minimum 2.2C with a touch of ground frost (-1.4C). Air pressure was steady on 1029 mb with high-pressure to the S 1036 mb Spain and 1035 mb SE Europe. Low 971 mb was N of Iceland while a low over Biscay was losing its identity another 970 mb was over the Atlantic to the west. It was sunny along the North Wales coast to N and N E England while SE England had mist and fog. Visibility was good and it was possible to make out the last remnants of a snow patch on Carnedd Llywelyn, otherwise snow was absent from the mountains (Loch Glascarnoch 10.7C Milford Haven 9.2C Redesdale Camp -6.7C Plymouth 3.0 mm Leeming 5.3h Hawarden 5.1h) [Max 8.6C Min 2.2C Grass -1.4C Rain nil]. Jasmine has been flowering in the garden all winter.A mostly cloudy and very windy day on the 2nd with a deepening depression 986 mb W of Shannon, Ireland. A cold front lay W of Ireland to Cape Wrath. The SW'ly was blowing force 6/7 with strong gusts. We were in warm sector air (8.6C just before 0900 GMT), the temperature rising through the day reaching 10.4C by 2037 GMT and 11.9C at Gorwel. Rain in the afternoon from 15-1730 GMT was moderate to heavy at times (5 mm/h at 1600 GMT). A gust of 43 mph was recorded at 1600 GMT at Gorwel Heights, Llanfairfechan (Bude 12.0C Hawarden 11.9C Shobdon -0.4 C Achnagart 39.6 mm Capel Curig 18.8C Leconfield 1.6h Valley 0.0h) [Max 10.4C Min 2.3C Rain 9.8 mm]. A fine morning on the 3rd with a clearing sky and pressure 1022 mb rising rapidly. Atlantic-high 1032 mb was W of Cap Finisterre, a cold front had passed over at 0212 GMT. There was a burst of rain (12 mm/h) and the wind backed SW to N then fell calm. Currently the front was lying SW England to the Wash. We had a dry sunny day with Valley reporting the most sunshine (Swanage 11.0C Pembrey Sands 9.2C Kielder Castle -0.2C Santon Downham 14.2 mm Valley 5.7h) [Max 8.4C Min 4.5C Grass 0.1C Rain trace]. Well we did have a nice day yesterday. Today the 4th in contrast began with overcast sky, fine drizzle and poor visibility. Pressure was steady on 1034 mb with high 1039 mb over Biscay. Low 971 mb was over the Denmark Strait with associated fronts N of Scotland. We had some light showers of rain then in the afternoon the cloud thinned to give some sunshine before dark (Achnagart 10.9C Mumbles Head 10.5C Baltasound 4.9C Benson -0.7C Kinlochewe 23.6 mm Leconfield 5.9h Aberdaron 4.3h) [Max 8.3C Min 3.5C Grass -0.6C Rain 1.2 mm].

    The 5th began fine and breezy with moderate misty visibility. Pressure was on 1020 mb with high 1038 mb over Brittany. Looking a little brighter the cloud seemed to be breaking, but soon thickened again with drizzle and slight rain interspersed with promising brighter spells (Aberdeen 12.5C Wattisham 1.6C Achnagart 20.2 mm Capel Curig 12 mm Boulmer 2.2h Hawarden 1.6h) [Max 9.1C Min 5.8C Rain 1.8 mm]. Snowdrops had been flowering in the garden since 31 December 2019.A very windy day on the 6th with pressure 1012 mb falling rapidly. Low 959 mb was just S of Iceland and there was a cold front over Ireland and western Scotland. There was a band of rain over the Irish Sea at 0900 GMT. During the morning Gorwel Heights had a gust of 50 mph, there were gales on high ground with Capel Curig reporting gusts of 63 mph (Lossiemouth 11.9C Leek 6.9C Okehampton 4.2C Achnagart 25.2 mm Whitechurch 14.8 mm Shoeburyness 3.4h) [Max 9.9C Min 7.0C Rain 6.0 mm]. Derek Brockway BBC Wales weatherman.Another wet and windy day on the 7th the sky overcast at 0900 GMT with slight rain and moderate visibility. Blustery SSW'ly wind strong to gale force in the afternoon. I tried going for a walk, but gave up as on reaching the first corner the wind was so strong that it was too dangerous to continue on the road; the Britannia Bridge had a 30 mph restriction imposed. South Uist reported gust of 67 mph, Capel Curig 55 mph and 51 mph at 1230 GMT at Gorwel Heights in Llanfairfechan. Record Föhn-enhanced temperatures were recorded today 15.3C at Murlough Bay in County Antrim, Northern Ireland, and 16.9C at Gorddinog and 17.4C at Gorwel Heights in Llanfairfechan at 1250 GMT both stations beating the previous highest 15.0C recorded at Rhyl in 1934 and at St. Abbs Head in 1989 (TORRO). The 17C Llanfairfechan temperature was featured by BBC Weatherman Derek Brockway on the 6.30 Wales News this evening (Murlough 15.3C Porthmadog 10.2C Lo min Shawbury 0.8C Porthmadog 1.6C Cassley 60.0 mm Capel Curig 11.4 mm Kinloss 2.6h Hawarden 0.8h Valley 0.0h) [Max 11.5C Min 4.4C Grass -0.1C Rain 1.2]. A promising start to the 8th with a few breaks in cloud overhead the station, Although pressure 1021 mb rising from a low of 1014 mb at 0017 GMT, hopes soon dashed as closed over again. Remnants of snow seen on Snowdon in the afternoon. It kept fine and dry though cloudy with occasional appearances of weak sunshine as cloud thinned a little. Rain came along by evening moderate to heavy at times, a pretty wet day in Wales overall [Capel Curig 24.4 mm Lake Vyrnwy 23.0 mm Sennybridge/ Mumbles Hd. 17.0 mm Llansadwrn 16.0 mm] (St James Park 12.3C Aviemore 1.2C Cassley 21.6 mm Cardiff 11.4 mm Dyce 5.1h St Athan 0.8h Valley 0.0h) [Max 9.8C Min 6.8C Rain 16.0 mm] . Another grey and dull January morning on the 9th, damp and misty with drizzle. Pressure was rising quickly with low 993 mb over the Celtic Sea tracking towards Brest 997 mb by noon. The afternoon was better and suitable for walking with glimpses of weak sunshine, but cold maximum 5.5C (Writtle 14.1C Lo Max Balmoral -0.2C Min Kinbrace -2.9C Capel Curig 24.8 mm Dundrennan 4.7h Lake Vyrnwy 0.5h Valley 0.0h) [Max 5.5C Min 3.7C Rain 0.3 mm].

    A nice winter's day had to come along sometime. The 10th was a nice day after some clear overnight sky leading to a ground frost (-1.6) some cold rain then a rapid clearance at 0900 GMT. Our resident mistle thrush was singing closeby; visibility poor to moderate, fog was lingering in the Menai Strait. Pressure 1024 mb was rising in a ridge from the Azores. Low 959 mb was S of Iceland and isobars were tightening to the north-west. Improved visibility and strengthening WSW'ly wind in the afternoon, sunny, fresh snow seen on the Snowdonia Mountains (Scilly 10.9C Braemar -7.9C Dunstaffnage 20.8 mm Wittering 6.0h Aberporth 5.0h Valley 4.2h) [Max 9.7C Min 2.3C Grass -1.6C Rain 0.4 mm]. Heavy rainfall in Wales on the 11 January 2020.Things got rather rough after midnight on the 11th with Valley reporting gales from 04 to 06 GMT and 09 GMT. The obs were fun, my hard hat was employed, visibility very poor and it was raining - the observer did not linger. Gusts of 42 mph here, 49 mph at Gorddinog, 58 mph at Gorwel Heights, 54 mph at Capel Curig and 61 mph at Aberdaron. Pressure 1014 mb was falling with Icelandic low 951 mb and southern highs 1035 mb Iberia and SE Europe centered near near Verona, isobars were tight to the NW of here. AWS rainfall record 24h to 09 GMT on the 12th.We were in warm sector air before a cold front over the North Channel reached us. Wind and rain kept on all day, here gusting to 53 mph coinciding with torrential rain 16 mm/h (more intense in Llanfairfechan, Gorwel Heights 51 mm/h and Gorddinog 84 mm/h) 1520-1536 GMT as the cold front arrived. The temperature that had reached 10.6C at 1602 GMT fell with the barometer bottoming out at 1011 mb and wind speed moderating. There was another spell of moderate to heavy (29 mm/h 2213 GMT) rain here from 20 GMT to midnight. Rainfall in the 24h from 0900 GMT was 32.5 mm. Wales seemed to have the some of the best and worst of the weather today [Hawarden 13.9C Gorwel Heights 13.1C Min Tredegar 5.0C Capel Curig 62.6 mm Shap 43.2 mm Llansadwrn 32.5 mm Sennybridge 32.2 mm Lake Vyrnwy 21.0 mm Mona 17.8 mm Aberdaron 10.0 mm Valley 9.6 mm Rhyl 6.6 mm Hawarden 2.2 mm Sunless day] [Max 10.6C Min 3.4C Rain 32.5 mm].

    The weather was quieter after midnight on the 12th and by morning the sky was starting to clear. The wind had dropped to force 3 and visibility was good with the cloud lifting. The ground was very wet indeed with pools of water here and there including on fields and farm gateways. Pressure was 1014 mb; and still high 1036 Iberia while complex low 958 mb was near Iceland. Brighter weather with some sunny spells developed by 1030 GMT with 2.4h of sunshine at RAF Valley. We were not out bad weather yet, a potentially damaging depression was developing rapidly 994 mb S Greenland and named Storm Brendan by the Irish Met Service (Met Éireann) who expected it to reach W of Ireland tomorrow, had deepened to 952 mb by midnight (Hurn 12.4C Aboyne -4.2C Cardiff 19.2 mm Katesbridge 5.6h) [Max 7.7C Min 5.5C Rain 0.3 mm]. Tweet about Storm Brendan.The 13th dawned with a S'ly force 5/6 wind and pressure 1002 mb dropping rapidly. Storm Brendan was deepening 948 mb W Northern Ireland at 0900 GMT then tracking N was 941 mb W of Scotland at 1800 GMT. South-west Ireland bore the brunt of the storm; Roches Point at the entrance to Cork Harbour recorded a gust of 84 mph. The wind strengthened here during the morning average gust speed from 1230 GMT to 1540 GMT was 43 mph, there were spots of rain from 1300 GMT. Between 1520 and 1550 GMT things got lively as the line front past over with heavy rain and ice pellets (falling at a rate up to 54 mm/h) blowing on the strong wind, highest gust 53 mph before moderating quickly. The hail covering the ground and greenhouse glass. Gorddinog reported a peak gust of 57 mph, Gorwel Heights 59 mph, Valley 65 mph, Mona 66 mph, Capel Curig/ Mumbles Head 80 mph (Egham,Surrey 11.7C Topcliffe 0.2C Achnagart 27.2 mm Libanus 22.0 mm Shoeburyness 3.6h Hawarden 0.2h) [Max 9.3C Min 4.1C Pptn 14.2 mm].

    The 14th the sky was overcast uniformly grey with moderate visibility, there was a lighter SW'ly breeze. With saturated soil the rain had pooled and roadsides were awash. Pressure 989 mb was falling with complex low 940 mb SE Iceland with another low developed off Brest was 981 mb Fastnet at noon and moved rapidly to be 979 mb over the North Sea off Hull at 1800 GMT. A cold day sunless day with light showery rain and drizzle throughout (Weybourne 14.6C Low Max Dalwhinnie 2.0C Mona 7.4C Min Dalwhinnie -0.1C Libanus 42.4 mm Kirkwall 4.7h Valley 0.0h) [Max 6.9C Min 4.2C Rain 17.2 mm]. An improvement on the 15th the sky clearing rapidly by morning. Windy in the west with gusts of 49 mph at Aberdaron and 62 mph at Malin Head during the morning. Pressure 998 mb was rising quickly as low 954 Iceland continued to fill. An occluded front lay to the NW over N Ireland and Scotland; a frontal band of cloud was over the English Channel clearing SE'wards. Between the two a welcome 6.1h of sunshine (Valley), most in the UK (Bournemouth 11.0C Dalwhinnie 0.3C Achnagart 45.2 mm Valley 6.1h) [Max 9.0C Min 4.8C Rain 0.4 mm].

    The first 15-days of January 2019 were unusually dry with just 7.5 mm of rainfall . Not so this year with rainfall of 101.3 mm (102%) & [99%] of averages. Temperatures both years were similar and on the mild side. This year the mean was 6.6C [+1.5], last year 6.4C [+1.3] of average.

    The morning of the 16th began fine and bright with just 4 oktas cloud cover. Visibility was very good an a little patch snow could be seen on Snowdon. Pressure 1007 mb was falling with a low 980 mb W of Ireland, there was a moderate to fresh SSE'ly breeze and cumulus clouds were towering over the mountains. Frontal cloud soon encroached off the Irish Sea and in warm air the temperature rose to 11.6C. Light rain began by noon and turned heavy at 1553 GMT and ceased by evening, returning before midnight. There was a burst of very heavy rain at 0446 GMT that fell at a rate up to 70 mm/h. Rainfall for the 24h [09-09 GMT] was 14.2 mm over 14 hours duration (Bude 13.1C Drumnadrochit 1.1C Tyndrum 26.8 mm Manston 2.7h Hawarden 0.1h) [Max 11.6C Min 5.0C Rain 24.2 mm] [Capel Curig 23.0 mm Mona 11.8 mm Valley 6.2 mm]. The 17th was a colder day with fresh snow on the mountains above 1800 ft and as a result Moel Eilio was doing its imitation of Mt. Fuji. A fall of snow pellets had been recorded by the hailometer. Pressure 1008 mb was rising again with yesterday's low 973 mb N of Scotland. The long cold front was lying over the North Sea, through France, Spain and S Portugal. Fine, but a bit dull with a cool WSW'ly breeze at first, sunny later (Santon Downham 10.6C Katesbridge -2.4C Achnagart 21.0 mm Swyddffynnon 16.0 mm Kinloss 5.5h Aberdaron 5.4h) [Max 7.5C Min 3.4C Pptn 0.5 mm].

    Llansadwrn view towards Gadlys and the mountains on a sunny afternoon.

    A fine frosty morning on the 18th with an extensive white frost on fields, grass minimum -4.5C and slight air frost -0.2C. Slight hoar frost with rime on the rim of the copper raingauge, there was ice on water, but the grassy ground was soft. It was calm with smoke rising vertically and there was low level mist and fog in the Menai Strait. Becoming rare these days a proper January morning with some sunshine later. Pressure 1028 mb was rising in a ridge from SE Europe, sunny most places except coastal mist and fog patches S coast of England (Scilly 9.3C Katesbridge -5.5C Bala -2.6C Altnaharra 9.0 mm East Malling 7.5h Valley 4.6h) [Max 7.1C Min -0.2C Grass -4.5C]. Another January morning on the 19th overnight the air minimum 0.7C and -4.0C on the grass the soil surface was frozen hard. Air frosts have become rarer, but we still get a fair number of ground frosts. Hoar on low vegetation and rime on raingauge. Most clear sky with very light SSE'ly air indicated by smoke drift, anemometer not turning. Pressure 1046 mb was rising with intense high 1044 mb Dublin. Very good visibility with inversion fog in the Menai Strait and a little mist at low levels, the snowline was 2500 ft on the Snowdonia Mountains. Fine and sunny (Stornoway 9.8C Lo Max Wellesbourne 1.5C Lo Min Topcliffe -6.8C Sennybridge -4.9C Lerwick 4.2 mm East Malling 8.1h Valley 4.2h) [Max 8.3C Min 0.7C Grass -4.0C Pptn nil]. The 20th began cloudier with 5 oktas cover at 0900 GMT, but it was decreasing. Not so cold overnight the air minimum 2.2C and -0.9C on the grass, but there was no frost left on the vegetation. Pressure was a high 1048.7 mb with 1049 mb centred on the Severn estuary and Sennybridge on a record 1050 mb. A sunny day (Altnaharra 12.3C Lo Max Llysdinam 3.0C Lo Min Yeovilton -4.8C Kinlochewe 2.6 mm Shobdon 7.6h Hawarden 7.1h Valley 6.1h) [Max 9.0C Min 2.2C Grass -0.9C Pptn trace].

    A dusting of snow on Carnedd Llywelyn.

    After three cold and frosty January days the 21st was a bit unusual. Pressure was on 1043 mb the centre moved to be off SW Ireland 1045 mb, intense high 1051 mb SE Europe, Verona. Moderate fog code 3 at 0900 GMT (fog code 2 is quite rare here, none last year). Sky overcast with drizzle persisted most of the day. Sea fog was general at noon N of Aberystwyth, Cardigan Bay, Irish Sea Isle of Man. Fog (hill) became thick code 1 at 16 GMT, less was reported in Llanfairfechan, but had cleared here by 2200 GMT (Aboyne 12.9C Benson -5.3C Resallach 13.0 mm Porthmadog 0.8 mm East Malling 8.4h St Athan 5.4h Valley nil]) [Max 7.6C Min 3.2C Grass -1.0C Rain 0.6 mm]. Unusual today to have fog code 2 on the 22nd at 0900 GMT with the sky obscured, it had been thicker after dawn; the Snowdonia mountaintops were in the clear. Pressure was on 1040 mb with high 1041 mb just off SW Ireland. The setting sun in fog at Gadlys. The jetstream was keeping well to the N around the high-pressure. The AWS temperature was 7.6C (dewpoint 7.0C) 96% RH; the dry and wet thermometers in the Stevenson screen read 7.6C, 100% RH. Soon it was a little brighter with some blue sky with some small cumulus clouds were visible overhead and later a foggy sun. Fog was dense in the Menai Strait between the bridges at 11 GMT. Fog began to decrease around noon, but returned later in the afternoon. The 14.5C maximum temperature at Aboyne today was just short of the 15.0C record at Llandudno for this day in 1960 (TORRO) (Aboyne 14.5C Lo Max Wych Cross 5.2C Lo Min Bournemouth -3.9C Resallach 8.0 mm Gogerddan 1.6 mm Morpeth Cockle Park 5.9h Valley 0.8h) [Max 9.6C Min 6.2C Pptn trace fog]. Another foggy day on the 23rd starting under mostly clear sky (3/8) with the sun rising above the mountains at 0843 GMT I recorded moderate low level fog increasing at 0900 GMT. The temperature was 5.1C (dewpoint 4.5C) 96% RH, the grass minimum thermometer was reading 0.0C, it was calm or variable light airs. Heavy dew and fog deposition, fine with weak sunshine in the fog. Mist or fog was reported in most places except NE Scotland where it was sunny. By 1030 GMT the fog had increased and was thick code 1 and by noon it was dense code 0 (Ravensworth 11.7C Topcliffe -1.7C Resallach 12.0 mm Lake Vyrnwy 0.6 mm Sheffield 6.2h Hawarden 4.4h) [Max 7.0C Min 4.6C Grass 0.0C Pptn 1.4 mm]. This pink Azalea has been in flower in the garden for a while.That's very unusual the fog was still with us on the 24th and it was dense code 0 at 0900 GMT with the sky obscured so that got a 9 in the cloud cover record. The temperature was 6.1C (dewpoint 5.6C) 97% RH, a light SW'ly breeze this morning and there was a fine drizzle too. A jet from RAF Valley passed over, could not see it, it was not foggy at Valley (METAR accessed EGOV 240920Z 29004KT 9999 FEW007 BKN013 OVC019 07/06 Q1023 TEMPO BKN019 RMK GRN TEMPO WHT). Mist had been reported all night and no fog since yesterday afternoon The low cloud fog persisted all morning, lifted a little by 1330 GMT with slight rain and drizzle and was then variable moderate to dense fog till evening. Pressure at 0900 GMT was 1024 mb with high 1025 mb over the Celtic Sea, there was a frontal cloud band was over the North Channel (Bridlington 11.4C Sennybridge -1.0C St Bees Head 3.8 mm Leconfield 5.9h Bala 1.0h Valley nil) [Max 6.7C Min 5.7C Rain 0.8 mm].

    Enough of the fog and the 25th did not disappoint, moderate (misty) visibility, fine with a cool breeze despite being S'ly. At 0900 GMT pressure was on 1017 mb with low 968 mb SW Iceland. A trace deposit of mixed coloured dust was observed. There was a cold front lying to the NW of Malin Head. Temperature 5.8C (dewpoint 4.4C) 91% RH. Somewhat breezy around noon and there was slight rain at times. Another sunless day (Scilly 10.9C Valley 8.4C Leeming -0.5C Eskdalemuir 4.2 mm Whitechurch 1.6 mm Aberdeen 1.6h Valley nil) [Max 8.6C Min 5.6C Rain 1.8 mm]. The 26th was another dull sunless day. Starting with a blustery strong SSW'ly wind whipping up the waves around the coast. Pressure 1002 mb was falling quickly with low pressure 956 mb Greenland/ Iceland region and a cold front over the Irish Sea. The west was wet again while it was sunny in central England. The temperature here was 8.4C and struggled to 8,8C at 1026 GMT. Gorwel Heights had seen 10.1C at 0800 and Gorddinog 10.2 at 0930 GMT all maxima for the day. Thereafter the temperature dropped reaching a minimum 2.6C at 1845 GMT for 2 hours with a touch of ground frost before rising again. The soil was saturated, soggy and muddy. Showers developed before midnight with a heavy one at 2320 GMT with small hail (Exeter 10.9C Rhyl 10.0C Fyvie Castle 2.9C Achnagart 26.6 mm Whitechurch 14.0 mm Weybourne 3.0h Aberdaron 0.7h) [Max 8.4C Min 2.6C Grass -1.5C Rain 6.2 mm]. Showers after midnight, some with small hail 0058 GMT, interspersed with clear spells with bright stars shining. By the morning of the 27th the sky was mostly cloudy. At 0900 GMT pressure 997 mb was falling with a large complex low 960 mb SW Iceland encompassing the UK and the Bay of Biscay. Pressure was high 1027 mb over the Canary Islands. The snowline with 50% cover, or more, on the mountains was at 2750 ft with some (30% cover) as low as 2500 ft. Bright at times with a little sunshine and some spots of rain. Shower of snow pellets about 18 GMT (Scilly 10.2C Milford Haven 9.2C Aboyne -3.6C Tredegar 22.8 mm Morpeth Cockle Park 6.9h Hawarden 2.8h) [Max 7.2C Min 2.6C Grass -1.5C Rain 5.2 mm].

    This pink flowering heather Erica ssp has been flowering in the garden since Christmas 2019.

    Wintry showers overnight including both snow and ice pellets with some still remaining on the grass on the morning of the 28th. A fine morning with weak sunshine as the sun rose over the mountaintops. A light fall of snow had settled as low as 450 ft on the lower slopes of the Carneddau, but mostly above 1000 ft. Pressure 992 mb was rising, there was a cool SW'ly breeze, the air circulating from Polar Regions, the Denmark Strait and Norway, the result of a low 971 mb S Iceland and W Scotland. The temperature was 3.7C (dewpoint 1.8C) 87% RH. The western fringes had showers the result of packed marine convection to the north-west with frequent cumulonimbus, there was lightning recorded over Cumbria and NWS Ireland. Central England and the SE was mostly sunny (Scilly 8.8C Loch Glascarnoch -6.6C Dunstaffnage 20.6 mm Cardiff 11.0 mm East Malling 6.4h Hawarden 3.3h Valley 1.4h) [Max 5.8C Min 1.1C Grass -2.6C Pptn 0.8 mm]. Remnants of snow seen on Snowdon in the afternoon. A fine morning on the 29th with snow on the mountaintops of Snowdonia. Pressure was on 1007 mb and there was a moderate SW'ly breeze picking up giving a significant 4-degree wind chill at noon. Glimpses of sunshine then thicker cloud brought slight drizzle in the afternoon from 1500 GMT when it began to turn milder (Scilly 11.4C Fyvie Castle -3.2C Tulloch Bridge 41.6 mm Sennybridge 4.2 mm East Malling 7.2h St Athan 5.7h Valley 0.3h) [Max 9.1C Min 3.5C Grass -0.5C Rain 0.1 mm]. This dwarf white Rhododendron has recently started to flower in the garden.A mild, but breezy morning on the 30th with no overnight frost on the ground. The temperature at 0900 GMT was 9.0C rising from a minimum of 5.3C and was to reach 10.6C at 1126 GMT. Pressure 999 mb was falling with a low 972 mb off the Western Isles of Scotland, Tiree had had a gust of 46 mph. Another low mid-Atlantic 964 mb S of Greenland was heading our way helped along by the jetstream. It was bright with some sunshine in Conwy and brighter here mid-morning as the wind strengthening, mist and rain was prevalent in the NW and SW of Britain. At 1343 GMT the temperature had risen to 14.3C in Llanfairfechan at Gorwel Heights. This was a long way off the daily record of 17.2C recorded at Aber in 1929 (TORRO), but there for the breaking in view of the 17.4C recorded on the 7th of the month. Hill fog returned between 17 and 19 GMT (Exeter 14.4C Hawarden 13.8C Lo Max Baltasound 7.4C Lo Min Baltasound 0.4C Achnagart 36.4 mm Capel Curig 5.2 mm Thomastown 2.3h Hawarden 1.4h) [Max 10.6C Min 5.3C Rain 4.0 mm]. On the last day of the month the 31st, and sad final day the UK was a member of the European Union after 47-years, there were a few small snow patches and remnant cornices remaining on the highest mountain cliffs despite the mild temperatures. At 0900 GMT it was 9.4C after an air minimum of 6.4C and was to rise to 10.7C at 1321 GMT. The temperature at Gorwel heights had been 13.9C at 0620 GMT. With just a small amount of rain overnight there was standing water around and with near horizontal rain blowing across the fields on a force 6 SW'ly the observer got quite wet (Hawarden 14.2C Lo Max Baltasound 6.9C Lo Min Lentran 1.9C Achnagart 35.2 mm Capel Curig 25.2 mm Aberdeen 2.5h Hawarden 0.3C Valley nil) [Max 10.7C Min 6.4C Rain 7.2C].

    The month ended with a total of 154.2 mm of rainfall [151%] of average largest since 2016, one of the 13th wettest in Llansadwrn since 1928. It had been mild the mean temperature 6.4C highest since 2016 and the 8th warmest in my records since 1979. A rather dull month, nearly half the number of days in the month were sunless.




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    February 2020

    February 1 - a fine breezy morning with the cloud beginning to clear after yesterday's rain and some sunshine developing, visibility was poor in haze. Pressure 998 mb was rising with low 959 mb Norwegian Sea extending a trough to N Scotland. High 1030 North Africa had a weak ridge to the south-west. The W had showers while central England, the E and SE were mostly sunny. The sky turned cloudier around noon and there was a little slight rain and drizzle at times in the afternoon (Charlwood 13.9C Baltasound 3.1C Kinlochewe 38.4 mm Capel Curig 9.4 mm Hawarden 6.6h) [Max 8.9C Min 7.2C Rain 5.4 mm]. The 2nd began dull and damp after some overnight rain. Dark-tailed red squirrel a regular visitor to the feeder.Cloud was hanging as low as 1500 ft on the north-facing slopes of the Snowdonia Mountains. Pressure 1002 mb was rising slowly as a low 979 mb W of Ireland tracking NNE, there was an occluded front over the Irish Sea. Bands of rain were affecting central Scotland and the SW Approaches. Breezy around the coast with Aberporth reporting gusts of 40 mph. The morning was fine, but the afternoon had a very fine drizzle at times under thick cloud (Charlwood 13.9C Aboyne -6.5C Lake Vyrnwy 28.6 mm Lerwick 4.8h) [Max 9.9C Min 5.3C Rain trace]. A fine, but again dull morning on the 3rd with rain showers in sight affecting the western end of the Snowdonia Mountain range. Soon some fine spots were felt on the force 3 WSW'ly. Pressure 1013 mb was rising with a low 978 mb between Iceland and Scotland being influenced by a high 1024 mb W FitzRoy. A frontal system was moving SE across the Irish Sea bringing showers to the western fringe was yet to reach E England that was sunny. Marine convection was packed the NW behind the front. Glimpses of sunshine with the showers arriving bringing rain and small hail (ice pellets) around 11 GMT and similar later in the afternoon around 14 GMT. Slight snow was seen settled on the mountains above 1750 ft, but disappeared later leaving some older surviving snow patches (Heathrow 12.0C Aboyne -1.8C Achnagart 29.0 mm Lake Vyrnwy 14.4 mm Morpeth Cockle Park 7.2h Valley 1.4h) [Max 7.5C 5.6C Rain 0.6 mm]. Overcast sky once more, but today the 4th a gentle NW'ly. The cloud was fairly thin with some layering few clouds at low, scattered at moderate altitude, overcast above. Pressure 1023 mb was rising with high W of Brest expected to move NE towards the SW Approaches while low 995 was over the N North Sea. Western areas had showery rain especially over the mountains, otherwise dry with brief sunny spells was the order of the day (Carlisle 11.8C Dalwhinnie -0.4C Kinlochewe 10.4 mm Capel Curig 3.7 mm 6.5h Aberdaron 4.7h) [Max 8.4C Min 3.9C Grass -0.1C Rain trace]. Fairly cool overnight with an air minimum of 2.3C and a touch of ground frost (-0.9C). At 0900 GMT on the 5th the 7/8th cloud cover was allowing a little weak sunshine at times. Quite misty, or was it hazy, with only an outline of the mountains visible, technically as the RH was 94% it was haze and not mist. Pressure 1039 mb was continuing to rise with a high situated over the Severn Estuary near Swansea. Sunny spells had come along by 11 GMT, some fog lingered in England from the Thames to Merseyside (Chivenor 11.3C Cardiff 11.2C Aboyne -4.6C Dunstaffnage 2.8 mm Shoeburyness 6.8h St Athan 5.3h Valley 1.7h) [Max 8.9C Min 2.3C Grass -0.9C Pptn trace].

    Hardly a cloud in the sky so it was a sunny morning on the 6th with pressure steady on 1032 mb. Pressure was high Europe centre near Verona 1040 mb. Out in the wings were low 991 mb Greenland deepening 975 mb and low 972 mb W of Ireland. There was silver frost on the grass and visibility was good; Snowdon had a light covering of snow/ ice on its NE flank and summit. There was just an air from the SW and soon the temperature was rising from a minimum of 1.3C to 9.8C at 13 GMT. On the sheltered rockery bank a buzzing was heard in the afternoon as several bees, the first of the season, were feeding on masses pink flowering heather (Erica). Valley reported 8.3h of sunshine. Mist and fog lingered in many parts of S Wales and central England (Aboyne 11.6C Gogerddan 10.4C Topcliffe -4.9C Lerwick 2.0 mm East Malling 9.2h) [Max 9.8C Min 1.3C Grass -2.9C Pptn nil]. The Foehn-enhanced temperature brought out the first bees of the year spotted on flowering heathers.The 7th proved to be an interesting day with rare low relative humidity values recorded both here and in Llanfairfechan. Cold dry air had descended and at Gorwel heights at 0623 GMT 15% RH with a low dewpoint of -15.6C at 0558 GMT was recorded. In Llansadwrn I recorded a low 30% RH and -11.7C dewpoint at 0706 GMT and David Lee 27% RH at 1012 GMT at Gorddinog. It was noticeable that surface leaf litter in the woods was dry. In a light SSE'ly the temperature here rose from a minimum of 0.4C to a Föhn-enhanced 11.4C at 13 GMT, 12.4C at Gorddinog AWS at 1340 GMT, but at Gorwel Heights it rose to 13.1C at 1310 GMT highest on this day. The UK highest recorded is 16.8C in Durham in 1993 (TORRO). Soil moisture determined today in Llansadwrn was 53.7% dry mass, lower that its 70% saturation point. Rain came along in the evening (Bridgefoot 12.2C Lo Max Dalwhinnie 4.3C Lo Min Aboyne -6.6C Machrihanish 2.8 mm Shap 7.4h Bala 3.3h Valley 3.0h) [Max 11.4C Min 0.4C Rain 2.9 mm]. Although there were some clear spells overnight the air minimum on the morning of the 8th was 4.5C and there had been no ground frost. At 0900 GMT the sky was turning cloudier and the SSW'ly was a blustery force 5. The Met Office had been issuing yellow warnings for wind and rain for some days about Storm Ciara that was on its way. Preparations for the likely closure of the Britannia Bridge at some point took place during the day. It began to rain during the afternoon and turned moderate to heavy, the wind strong to gale force from 15 GMT. A gust of 46 mph was recorded at 2020 GMT. At Gorwel Heights a gust of 85 mph was recorded at 2320 GMT, several properties received minor damage including removal of tiles/ slates. Capel Curig had a gust of 86 mph (Cardiff 12.1C Dalwhinnie 0.6C Tyndrum 39.0 mm Capel Curig 8.0 mm Kinloss 6.8h St Athan 5.2h) [Max 11.1C Min 4.5C Rain 55.3 mm]. Heavy rainfall in Cumbria and N Wales on the 8 February  2020.The rain eased a little after midnight on the 9th, but not the wind. Just before 06 GMT as the wind strengthened again gusting to 57 mph and there was a torrential downpour of ice pellets and rain of 60 mm/h at 0625 GMT. At 0632 GMT thunder was heard and the electricity supply momentarily failed. Sferics were recorded over much of North Wales at the time Sferics at 0732z on 9 Feb 2020. Courtesy of blitzortung.org/. . At Gorwel Heights a gust of 62 mph was recorded at 0730 GMT. Storm Ciara closes Llansadwrn road with fallen tree and BT cable.A 57 mph gust of wind was recorded here at 0826 GMT. The wind brought down a tree across the road between Gadlys and the Church and with it the BT cable supplying phones and internet to six properties. This occurred just beyond the pole supplying the weather station house whose communications held. Conditions at 0900 GMT were atrocious in wind and rain. Pressure 976 mb was falling quickly and the temperature in the warm moist air was 11.1C, rainfall for the 24-h ending 09 GMT was [55.3 mm], Capel Curig reported [75.0 mm] and Shap Fell in Cumbria 88.0 mm. The Britannia Bridge was closed for a while and a landslide closed the A5 at Llyn Ogwen. At 10 GMT wind turbines were supplying 43% of the UK electricity demand. During the afternoon wind started to moderate and rain gave way to showers with glimpses of sunshine. There was flooding in the Conwy Valley and Llanwrst, the railway line to Ffestiniog was affected and closed. The wind was picking up again before midnight. The run of wind 00-00z in Llansadwrn today was 450 miles and at Gorwel Heights 305 miles (Donna Nook 14.8C Hawarden 14.6C Tulloch Bridge 0.0C Capel Curig 122.6 mm Leuchars 4.7h Valley 2.1h) [Max 11.4C Min 5.9C Rain 7.8 mm] [Capel Curig 54.4 mm Bala 34.2 mm Rhyl 26.6 mm].

    Wild wallflower flowering in the garden today. The 10th began fine, bright and blustery the WSW'ly force 6 and strengthening convective clouds building. Strong gusts over the mountains with Capel Curig reporting 64 mph. Sunny spells gave way to some weak sunshine as cloud developed. Pressure 994 mb had risen with low 943 mb Iceland. Ciara had moved over to Norway while pressure remained high 1036 mb Tunisia and 1035 mb E Mediterranean. Glimpses of sunshine around noon then it turned showery and at 1520 GMT we had a shower of snow pellets and small flaked snow. The native wallflower flowering today in the garden (right) is a bright golden yellow and survives on very little soil including the walls of Beaumaris Castle (Scilly 10.7C Lo Max Salsburgh 0.8C Lo Min Dalwhinnie -0.7C Millport 25.6 mm Bala 13.2 mm Aberdeen 7.2h) [Max 6.2C Min 3.6C Pptn 1.8 mm]. SKIRON Graphic courtesy of the University of Athens.On the 11th pressure 1003 mb was still rising with low-pressure to the N low 963 mb part of an Icelandic. Norwegian complex was N Scotland. The cold air upon us today was coming all the way across the Atlantic from the Canadian Arctic. It was breezy with cumulus clouds increasing we had been having snow pellet showers and some were lying on the ground. At 0900 GMT another shower of snow pellets the temperature 3.3C (dewpoint -0.2C) and 78% relative humidity. With some sunshine at times it was a blustery morning with a wind chill of -2C and poor visibility. Sferics were recorded to the N and S of here and near Dublin, but none near here (Shoreham 8.8C Altnahinch Filters -0.9C Cassley 30.8 mm Cardiff 3.2 mm East Malling 8.7h Aberdaron 6.7h Valley 4.4h) [Max 5.9C Min 2.2C Pptn 0.3 mm]. Tweet about winter flowering hellebores in the garden.There was a cold W'ly breeze on the morning of the 12th the airflow still from the Canadian Arctic. There had been slight shower(s) of snow pellets since midnight, but there was none on the ground. Pressure 1013 mb was rising with a high 1028 mb over the Charente Maritime, France, Atlantic-low 985 mb was W of the Scilly Islands. Most of southern Britain was sunny with cumulonimbus clouds and with the threat of showers W & NW Ireland and Scotland. Bright at first with snow seen on the Snowdonia Mountains as low as 1750 ft in places including Moel Eilio. Cloudy in the late afternoon with some fine drizzle (Scilly 9.7C Killylane -1.1C Cassley 39.2 mm Tredegar 4.2 mm Wattisham 8.3h Hawarden 6.7h Valley 6.3h) [Max 7.4C Min 2.1C Grass -2.0C Pptn 3.0 mm]. Breezy overnight and showery rain early on the 13th and moderate shower at 0900 GMT with puddles forming on the water saturated ground. Pressure 987 mb had fallen the result of low 983 mb N Ireland, but named Storm Dennis S of Greenland was undergoing rapid cyclogenesis 952 mb. Gales were occurring SW Cornwall and Scilly Islands with a gust of 64 mph experienced at Cardinham. The wind here had moderated, rainfall amounts were large in Llanfairfechan and over the Snowdonia Mountains (xx Cardiff 10.6C xx Tredegar 1.8C xx Libanus 30.2 mm xx St Athan 3.7h) [Max 8.2C Min 2.8C Grass -1.3C Rain 0.4].

    The effects of Storm Dennis began to arrive on the 14th with pressure 1008 mb falling rapidly at 0900 GMT. Dennis was 933 mb SW Iceland and expected to deepen to about 922 mb making it one of the deepest over the North Atlantic in 30-years. The SSW'ly wind was blowing force 7/8 on the exposed side of the Llansadwrn ridge, Capel Curig had reported a gust of 66 mph. A little brightness at first, a glimpse of sunshine the weak sunshine as the cloud on a frontal system over the Irish Sea bringing a band of moderate to heavy rain and rising temperature. Rain ceased in the afternoon as the wind moderated, the temperature rose to 10.7C here and to 11.6C at Gorwel Heights in the warmer air (Murlough 12.7C Gorwel Heights 12.3C Rhyl 11.7C Loch Glascarnoch -9.1C Braemar 20.6 mm Capel Curig 14.2 mm East Malling 6.0h) [Max 10.7C Min 2.8C Grass -1.5C Rain 6.4 mm]. Tidal elevations at Llandudno courtesy of UK National Tide Guage Network accessed 20/02/20. The 15th was overcast and dull with rain at 0900 GMT. Pressure 996 mb was falling with the Dennis complex low system 931 mb W of Scotland. The temperature was 10.7C (dewpoint 9.1C) 90% RH, rising to 11.1C late afternoon, the SW'ly force 6 and moderate visibility. The temperature at Gorwel heights at 0840 GMT was 12.3C. The rain turned moderate to heavy (17 mm/h at 1118 GMT) through the morning, was lighter in the afternoon when pressure reached its lowest 982 mb at 1720 GMT, with a lull in the evening before returning again moderate to heavy before midnight. The low pressure system resulted in a surge on the high tide at Llandudno of about 0.8 m late afternoon contributing to flooding of the River Conwy (courtesy of the UK National Tide Gauge Network). There was flooding of homes and businesses in several parts of Wales, Conwy Valley and South Wales valleys (Wellesbourne 13.9C Kielder Castle -0.4C Shap Fell 63.2 mm Tredegar 59.0 mm Thomastown 0.6h) [Max 11.1C Min 6.7C Rain 28.6 mm].

    Pressure associated with Storm Dennis S Iceland at midnight on the 16th was 923 mb and was falling again in Llansadwrn 982 mb reaching 981 mb at 03 GMT when the wind was gusting 45 mph. Tweet about Storm Dennis large hail. Photos courtesy of Gordon Perkins.At 0900 GMT it was 985 mb and rising and it had stopped raining.Run of wind 00-00z in Llansadwrn 12-18 february 2020. Rainfall in the past 24-h was 28.6 mm. Llyn Tegid at Bala had overflowed again and was covering the car park at the Visitor Centre. Strong winds again in the NW with South Uist reporting a gust of 70 mph at 10 GMT. The afternoon turned showery as a trough passed over North Wales producing some large hail up to 8-9 mm here, but at Gorwel Heights Gordon Perkins photographed hail stones of 2 cm diameter that fell covering the ground and the A55 near Llanfairfechan causing problems for passing traffic, and along the coast towards Queensferry where later there was heavy sleet. The surge on the high tides at Llandudno today were about 0.6 m (courtesy of the UK National Tide Gauge Network). The run of wind 00-00z in Llansadwrn today was 450 miles and at Gorwel Heights 302 miles(East Malling 13.0C Dalwhinnie -0.2C Tredegar 62.6 mm Aberdeen 6.7h) [Max 8.4C Min 6.1C Pptn 0.3 mm].Winter heliotrope in flower. It had been very windy overnight gusting 48 mph at 0114 GMT and in the morning of the 17th the sky had been clearing leaving a line of cumulus clouds over the mountaintops. At 0900 GMT pressure 1001 mb was rising but clouds were increasing, there was a moderate to strong SW'ly and the ground was drying. Visibility was poor in haze and there was some mostly weak sunshine at times in the morning becoming sunny in the afternoon spoiled by a shower of rain and small ice pellets at 1540 GMT. The winter heliotrope (Petasites fragrans) is in flower now. It has mauve-pink scented flowers (right) above a carpet of rounded leaves 20-30 cm high that persist until late autumn. Native to southern Europe naturalized in Britain where only male plants are found, spreads by rhizomes, is shade tolerant and can be invasive (Wisley 11.7C Dalwhinnie 1.0C Tyndrum 44.8 mm Usk 8.2 mm Aberdeen 8.8h Valley 5.7h) [Max 9.5C Min 5.3C Pptn 0.2 mm]. It was fair overnight with no precipitation, some clear spells with a grass minimum of -0.5C during the early evening. The morning of the 18th was fine and breezy with a moderato to strong SW'ly. Pressure 1014 mb was falling with low 971 mb (ex Dennis) mid Norwegian coast. Another low 979 mb was SE Iceland. Cloudier from 10 GMT with spits and spots of rain. More showery in the afternoon with 4-5 mm ice pellets at times (Heathrow 11.4C Dalwhinnie 0.2C Kinlochewe 24.8 mm Sennybridge 13.2 mm Aberdeen 6.4h) [Max 7.9 Min 4.1C Grass -0.5C Pptn 1.2 mm].

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    A dry night and overcast morning on the 19th and just starting to rain at 0900 GMT. Pressure 1018 mb was falling, there was an area of rain encroaching on a warm front from the Atlantic to the SW associated with low 957 mb S Iceland. The temperature in the warm moist tropical air rose through the day reaching 8.6C by 19 GMT. The day was sunless, continuous rain was light to moderate and, with little change in the air temperature, turned moderate to heavy before midnight (Scilly 11.1C Baltasound -1.8C Capel Curig 36.2 mm Weybourne 5.8h) [Max 8.8C Min 5.0C Grass 3.1C Rain 42.0 mm]. New kid on the tree this winter coated red squirrel with very long ear tufts.After midnight on the 20th it was windy with gusts of 38 mph, the rain continued and was intermittently moderate to heavy. At 0700 GMT the temperature had risen to 8.8C as the cold front arrived the wind moderated. There was a burst of very heavy rain and ice pellets at 0849 GMT falling at a rate up to 44 mm/h. There was much standing water and runoff from fields with local roads awash. At 0900 GMT still raining heavily pressure 1002 mb was rising quickly. The morning soon cleared up and by afternoon it was sunny. A shower of rain and ice pellets fell at 1530 GMT then cleared to sunny again (Bridlington 12.2C Loch Glascarnoch 0.2C Shap 50.4 mm Capel Curig 49.8 mm Kinloss 5.0h Aberdaron 4.8h) [Max 8.1C Min 2.8C Grass -0.5C Pptn 2.6 mm]. The wind gradually strengthened overnight and by the morning of the 21st it was blowing half a gale with gusts of 42 mph. There were spots of rain of rain on the wind and serious rain began soon after 0900 GMT. Pressure 1015 mb was falling with complex Icelandic low 956 mb with associated triple point near the Western Isles of Scotland. We were in warm sector air the 8.1C temperature warmest of the last 24h. The Met Office issued a yellow rain warning for mountain areas of N Wales at 1050 GMT. Light rain through the morning turned moderate by the afternoon...

     

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