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

Llansadwrn (Anglesey)

Latest Diary 2019

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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 (first indications) are given in bold and are usually 21-21 GMT. When averages are referred to (.) compares with the last decade and [.] with the30-y climatological average [1981 - 2010]. All data are subject to verification and amendment.

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October 2019

October - began dull and wet with a low 993 mb over the Celtic Sea. The barometer had bottomed out at 995 mb at 0154 GMT and at 0900 GMT was rising on 997 mb. It was calm with slight rain in moderate visibility. Llyn Tegin at Bala was still flooding the car parking area and there was severe flooding at Laxey on the Isle of Man. Although there was brightness to the N in Llansadwrn the day was sunless (Trawsgoed 21.3C Kinbrace -1.8C Carlisle 41.2 mm Tredegar 27.6 mm Glasgow 8.7h) [Max 15.2C Min 12.1C Rain 1.0 mm]. The sky had cleared overnight and on the morning of the 2nd it had been cool with an air minimum of 6.1C and 2.4C on the grass. Cloud had encroached by dawn but at 0900 GMT there were 3 oktas and clearing here although the mountains remained mostly cloudy. Pressure 1020 mb was rising with high 1022 mb just W of Iberia and complex low-pressure 987 mb over the Baltic. Hurricane Lorenzo category 5 was at latitude 40 degrees N just W of the Azores, it was the strongest and most easterly hurricane to reach this region. Cloudier again here around noon then brighter late afternoon and evening (Plymouth 16.7C Tyndrum -2.7C Baltasound 8.2 mm Hawarden 0.6 mm East Malling 11.4h Hawarden 6.3h) [Max 13.6C Min 6.1C Grass 2.4C Rain nil]. It had been cool overnight night and on the 3rd the air temperature had been down to 4.1C and 0.9C on the grass. At 06 GMT with a SSE'ly breeze the sky was clear here and it was misty with the sky taking on an odd pink colouration. Moderately high cloud had encroached from the W, bringing a little rain to parts, the main rain area was W Ireland. Pressure 1016 mb was falling quickly and ex-hurricane Lorenzo 969 mb was off SW Ireland. High 1023 mb was over N France near the Belgium border, and high 1027 mb N Norwegian Sea. There was slight rain here just after noon and moderate to heavy rain in the evening with the wind gusting to 32 mph here, 40 mph at Gorddinog (1728 GMT) and 39 mph at Gorwel Heights (1841 GMT) where the temperature reached 16.5C at 1900 GMT (Plymouth 16.3C Mumbles Head 15.7C Dalwhinnie -2.9C Finner, Ireland [49.0 mm] Thomastown 25.0 mm [28.6 mm] Capel Curig 18.4 mm] Scolton Country Park 14.6 mm Stornoway 5.2h Bala 0.9h) [Max 14.1C Min 4.1C Grass 0.9C Rain 18.6 mm]. Very dull and wet on the 4th looking grey to ground with moderate to very heavy rain moving SE across the Irish Sea from N Ireland. Continuous rain was heaviest here around 0815 GMT when falling steadily up 9.2 mm/h . Heavy rain crossing the Irish Sea at 09 GMT towards Anglesey and Snowdonia (Courtesy of MeteoGroup).At 0900 GMT 18.6 mm of rain had fallen in the past 24-h and there was some standing water in places. Remnants of H Lorenzo had mostly fizzled out and was slow-moving over the Irish Sea reaching Cardigan Bay at noon, pressure here was fairly steady on 1010 mb. There had not been much wind near the centre of the low, gust 21 mph overnight. Brighter later in the afternoon and evening the breeze moderating further. The low tracked over S Wales 1006 mb at 18 GMT towards the Channel and then the Netherlands (Hurn 18.2C Salsburgh 5.9C Trawsgoed 18.6 mm [17.2 mm] Capel Curig [7.6 mm] Kirkwall 7.6h) [Max 15.1C Min 8.8C Rain 3.4 mm].

The 5th was overcast with moderately high cloud just touching the mountaintops of Snowdonia. A warm front associated with low 964 mb SE Greenland lay over the Irish Sea. At 0900 GMT the temperature was 13,2C RH 88%. It had been dry overnight, the morning remained dry, but rain came along just after 16 GMT. (Bude 17.7C Altnaharra -2.7C Murlough 24.8 mm Scolton CP 18.4 mm Lerwick 5.5h St Athan 0.7h) [Max 15.1C Min 11.2C Rain 9.6 mm]. A bright morning on the 6th with a light SW'ly breeze. Pressure 1012 mb was rising in a minor ridge from high 1026 mb W of Iberia. There were showers with sunny spells over the Snowdonia Mountains (Pershore 18.5C Braemar 7.2C Tibenham 47.2 mm Lake Vyrnwy 12.0 mm St Athan 9.5h) [Max 14.8C Min 10.9C Rain 3.2 mm]. There was rain after midnight on the 7th with pressure falling from 1015 mb to 1008 mb by 0900 GMT. It was breezy the S/SE'y force 5 with a temperature of 13.0C; it was windy too at Gorwel Heights the SE'ly gusting 37 mph at 0616 GMT with the temperature 16.1C at 0900 GMT. At 1324 GMT a temperature of 18.1C was recorded. The day was mostly dry, a few spots of drizzle at times, and sunless (North Wyke 17.5C Rhyl 17.1C Marham 4.9C Culdrose 27.2 mm Magilligan 6.4h Bala 0.5h) [Max 16.3C Min 9.8C Rain 0.3 mm]. A fine and largely sunny morning on the 8th after some slight showers of rain before 0900 GMT. There were some towering cumulus clouds in the vicinity but the sky was clearing and the morning and afternoon mostly sunny. Pressure 1002 mb was falling slowly with low 963 mb between SE Iceland and NW Scotland. The afternoon was bright and breezy gusting up to 26 mph and there was a brief heavy shower at 1630 GMT. The Michaelmas daisy has a mass of flowers in the garden at the moment, flowering a little later this year, and was attracting many butterflies. Five red admirals and four commas as well as a painted lady were seen (Kew Gardens 18.0C Fyvie Castle 4.6C Achnagart 51.2 mm Sheffield 8.1h Valley 6.1h) [Max 14.4C Min 11.5C Rain 2.2 mm]. A mostly cloudy morning with early showers on the 9th with a heavy shower around 0900 GMT that included ice pellets. There was a slow-moving low 975 mb over N Scotland and we had a strong SW'ly airflow packed with showers. The temperature was 9.5C rising to 13.8C in the afternoon that was mostly sunny. There was further light showery rain from 17 GMT into the evening (Hurn 16.8C Altnahinch Filters 6.2C Achnagart 39.6 mm St Athan 33.0 mm Leconfield 6.3h Aberdaron 5.8h Valley 4.8h) [Max 13.8C Min 9.5C Rain 3.6C].

The sky was overcast at dawn on the 10th, but at 0900 GMT there was patch of blue sky overhead. Pressure was on 1008 mb with lows 981 Norwegian Sea and 985 mb S Iceland W of Scotland. A bright and breezy morning the WSW'ly force 5, there was a very rough sea running at Rhosneiger. An area of rain associated with a warm front was approaching over the Irish Sea. Yellow warnings had been issued for rain in Wales (except Anglesey) and the Manchester area. A wet, windy and sunless day (Hurn 17.7C South Newington 4.2C Tyndrum 34.6 mm Capel Curig 23.8 mm Manston 8.1h Hawarden 2.1h Valley 0.0h) [Max 14.1C Min 9.3C rain 13.5 mm]. At 03 GMT on the 11th there was a burst of very heavy rain that fell at a rate of up to 100 mm/h. At 0900 GMT the sky was still overcast with grey moderately high cloud just touching the Snowdonia mountaintops. The level of water in Llyn Tegid, Bala, was rising again, where 37 mm of rain had fallen, partially flooding the car park at the visitor centre. Brighter in the afternoon with some glimpses of sunshine and a few spots of rain (Cromer 17.7C Baltasound 4.8C Achnagart 51.4 mm Bala 37.0 mm Charterhall 8.2h Valley 3.1h) [Max 14.8C Min 10.6C Rain 0.2 mm]. A bright morning on the 12th with 5 oktas of cirrus and cumulus clouds. Pressure 1005 mb was rising and the weather was the best in the NW today. The sky cleared over Anglesey and it was a dry mostly sunny day, a line of cumulus clouds persisted over Snowdonia (Myerscough 16.3C Katesbridge 1.3C Swanage 21.4 mm Gogerddan 10.8 mm Dyce 9.5h Valley 7.3h) [Max 15.8C Min 8.0C Rain 2.2 mm]. Although the sky had been clear overnight with a bright hunters' moon, by the morning of the 13th it was back to normal with the sky overcast and raining. Pressure was 999 mb was falling and reached its lowest 997.6 at 1300 GMT when the wind that had been light and suddenly strengthened. The rain light to moderate turned heavy (18 mm/h) at 1249 GMT before soon easing and brightening a little, but there was no sunshine (Manston 18.4C Aboyne -2.9C Aberdaron 37.4 mm Lerwick 7.1h Aberporth 2.9h Valley 0.3h) [Max 12.7C Min 8.8C Rain 11.4 mm].

Overnight once again the sky was clear for many hours with a bright moon. By the morning of the 14th the sky was covered with fairly thin moderately high cloud with weak sunshine at times. Pressure was on 1006 mb with low 996 mb over the Celtic Sea tracking towards S England 999 mb at 18 GMT. A dry day with no bright sunshine. Once again the sky cleared at night with the bright moon shining (Manston 17.3C Valley 15.4C Kinbrace -0.9C Little Rissington 20.4 mm Sunniest Dyce 7.4h Hawarden 0.5h) [Max 14.1C Min 8.4C Rain nil]. The 15th began mostly cloudy, but fine and feeling fresh. Visibility was clear and very good. The breeze was ESE'ly and light. It was a very nice sunny afternoon when several butterflies were seen again on the Michaelmas daisy. These included red admiral, small tortoiseshell, comma and painted lady (St James Park 17.7C Aviemore -1.3C Scarborough 13.0 mm Mumbles head 9.4 mm Loch Glascarnoch 7.3h Aberdaron 5.1h) [Max 16.8C Min 7.6C Rain 1.0 mm].

The first 15-days of the month had 70.2 mm of rainfall (64%) & [55%] of averages. Temperatures were a little above average the mean 11.9C (+0.4) & [+1.1] of averages. The highest maximum 16.8C was 3 degrees below normal.

A fine and cool morning on the 16th with moderate to good visibility. It was hazy and the mountains were visible as just outlines where cumulus clouds were building bringing showers of rain. Pressure 999.8 mb was rising with a low 969 mb S of Iceland and W of Scotland, there was an occluded from lying W of Scotland over the Isle of Man to Thanet. Here mostly sunny although cloud did build around noon producing a shower or two. Butterflies were on the Michaelmas daisy and one or two birds were around, There are rather few in the garden at the moment, we have seen male and female spotted woodpeckers on a peanut feeder, a robin that frequents the vegetable plot as I clear away the finished rows of peas, and a few tits in the trees. It seems they have no need for additional feeding at present the weather mild (Shoeburyness 18.0C Aviemore 1.1C Machrihanish 27.8 mm Aldergrove 9.2h Aberdaron 8.4h) [Max 14.2C Min 9.1C Rain 1.4 mm]. The sky kept clear at first overnight and on the 17th, turning cloudier there was a moderate shower at 0356 GMT, but the air minimum at 0500 GMT was 8.8C and on the grass it had fallen to 4.0C after clearing. The wind had backed S'ly and was force 4 at 0900 GMT soon strengthening and becoming blustery. Pressure was on 1001 mb with a depression 977 mb W of Scotland. There were numerous shower troughs in the SW and convective clouds developed with cumulonimbus in the vicinity. Showers and rain in the afternoon from 16 GMT that fell briefly at a rate up to 25 mm/h. In all there were 7 sharp showers during the 24-h (09-09z) in which 12.7 mm of rain fell over 10 wet hours duration (Cardiff Bute Park 16.5 C Kinbrace -4.4C Valley 20.8 mm [29.0 mm] Mona [19.2 mm] Capel Curig [14.6 mm] Morpeth 8.9h Valley 3.5h) [Max 12.2C Min 8.8C Grass 4.0C Rain 15.4 mm]. It was still showery on the 18th with the latest just stopping at 0900 GMT. Pressure was low 993.7 mb with a depression 989 mb over Shannon at 06 GMT moving eastward towards the Irish Sea. Pressure was lowest 991 mb at 1656 GMT as the depression passed over on its way to the North Sea. Frequent showers again during the day with a few sunny intervals (Herstmonceux 16.0C Katesbridge 0.5C Dundrennan 44.0 mm Usk 35.8 mm Lerwick 5.7h) [Max 11.6C Min 7.8C Rain 21.4 mm]. Heavy rain at 0243 GMT beating on the slates at a rate up to 73 mm/h or as the AWS said 'raining cats and dogs'. A very dull and wet day on the 19th with grey to ground overcast sky at 0900 GMT with rain and poor misty visibility. A depression 994 mb was over Morecambe Bay and pressure here 998 mb was rising. Mona reported (22.2 mm rain 21-21z) and the fall measured here in the same period was (21.8 mm). A sub 10C day as well, the 9.9C being the lowest since the 8.7C on 8th May 'At 0900 GMT with slight rain visibility was deteriorating moderate to poor; the temperature was 7.1C. Pressure 991.6 mb was falling rapidly reaching 984.9 at 1409 GMT, Slight intermittent rain continued, moderate for a time in the afternoon, through till 18 GMT. The temperature struggled to rise to 8.7C at 1442 GMT, this was the lowest May maximum since the 8.5C in 1997 and was 5th lowest on record here; 1979 had 7.2C on 1st and 2nd; and 1983 had 7.2C on the 1st' (Plymouth 16.6C Cardiff 15.5C Low max Braemar 8.1C Kielder Castle -0.8C Edinburgh Botanic Gardens 31.0 mm Mona 22.2 Llansadwrn 21.8 mm Almondsbury 8.0h) [Max 9.9C Min 7.2C Rain 21.4 mm].

A fine morning on the 20th with very good visibility and some towering cumulus clouds over the Snowdonia Mountains. Pressure 1014 mb was rising quickly with an Atlantic-high 1029 mb N of the Azores having a ridge to Iceland dominating the weather. There was low pressure 1001 mb over S France and S Norway. There was a cool fresh feeling N'ly breeze and sunny spells through the day (Langdon Bay 14.1C Mumbles Head 13.6C Sennybridge -0.1C Fylingdales 11.8 mm Capel Curig 3.0 mm St Athan 7.4h) [Max 11.3C Min 7.9C Pptn 0.3 mm]. A rather dull mostly cloudy morning on the 21st, but it soon started to brighten up with some sunny spells developing particularly in the afternoon. Pressure was 1024 mb with high 1028 mb W of Cap Finisterre having a ridge to NW Britain giving us settled weather. Pressure was low 1010 mb over Belgium while depression 989 mb had moved over Iceland. The light N'ly breeze lessened late in the afternoon with the temperature falling away to <9C by evening. Wet in SE England (Chivenor 15.2C Tulloch Bridge -5.5C Manston 17.0 mm Katesbridge 8.2h Aberdaron 5.9h) [Max 11.9C Min 8.6C Rain nil]. The 22nd was a fine dry day starting mostly cloudy with a light SSW'ly breeze and pressure steady on 1022 mb. Pressure was low 966 mb over the Norwegian Sea with high-pressure 1024 mb over France with a ridge t S Britain. Visibility was very good and clear; a few patches of blue sky overhead at 0900 GMT expanded to give a little sunshine in the afternoon (Wiggonholt 17.1C Mumbles Head 16.0C Topcliffe -1.0C Lerwick 21.8 mm Herstmonceux 8.0h) [Max 12.2C Min 7.4C Rain nil].

The 23rd began very fine with sunny spells, a temperature of 10.9C and a drying S'ly breeze (83% RH). A band of rain on a cold front lay in the W from Ireland to Scotland associated with a low 992 mb over Rockall. Pressure 1013 mb here was falling. A low 1004 mb was near Biarritz, France, there had been storms resulting in flooding in S France and Catalan, Spain. The day kept dry, with the later afternoon turning mostly cloudy (Chivenor 16.0C Rhyl 14.8C Shobdon -0.5C South Uist 32.6 mm Camborne 8.2h Bala 8.1h Valley 1.0h) [Max 13.5C Min 9.2C Rain 0.3 mm]. After some light showers of rain after dawn on the 24th the sky began to clear leaving a line of cumulus clouds over the Snowdonia mountaintops. Pressure 1003 mb was rising a little; low 981 mb over the Norwegian S had an associated cold front charted at 06 GMT over N England, Wales and Cornwall. An associated low 985 mb over Rockall had a frontal system over N Ireland and W Scotland. The morning was fine and bright with weak hazy sunshine the sky clearing to give a sunny afternoon when the temperature rose to 14.2C. Later moderate rain fell from 1730 GMT becoming heavy at 1743 GMT just before thunder was heard at 1746 GMT (Cardiff 16.4C Shawbury 3.6C Achnagart 23.8 mm Capel Curig 8.0 mm Dyce 6.4h Valley 6.3h ) [Max 14.2C Min 9.8C Rain 5.6 mm].

On the 25th an Atlantic warm front, associated with a large tropical depression 980 mb over the Azores, brought an overcast sky with moderate rain and very poor visibility before 0900 GMT. Pressure here was 1009 mb with a frontal-wave low 1001 mb developed over Cardigan Bay. To the N low 977 mb over the Faeroes had brought cooler weather to Scotland with snow falling on Cairngorm Mountain A wet day ensued with 23 of the 24 hours (09-09 GMT) recorded at 'wet'. The day was sunless and also quite dark under a thick blanket of cloud with 0.97 MJ m -2 solar radiation the lowest of the month, the maximum temperature was only 8.7C, lowest of the month so far. Total rainfall was 34.8 mm, largest of the month (Bude 17.1C St Athan 16.0C Katesbridge -3.6C Libanus 52.4 mm Kinloss 8.2h Valley 0.0h ) [Max 8.7C Min 5.4C Rain 34.8 mm]. A grey and wet morning on the 26th with a temperature of 5.8C at 0900 GMT. Pressure was on 1007 mb with lows 997 mb Azores and 984 mb Fair Isle. The ground was soggy underfoot with a few small puddles developing. A slow-moving warm front was over the Severn estuary, it was warmer and wetter in South Wales and cooler here where air from Polar regions was being drawn down around the depression over the Norwegian Sea (Frittenden 19.2C St Athan 15.5C Balmoral -2.6C Libanus 70.0 mm Kinloss 7.9h Aberdaron 2.0h) [Max 8.2C Min 5.8C Rain 1.2 mm].

A much brighter day on the 27th with sunshine developing later. It was still a cool 5.3C at 0900 GMT when visibility was a misty moderate to good after a ground frost (-1.0C). Pressure had risen to 1025 mb with an Atlantic-high 1028 mb W of Ireland. Complex low-pressure 993 mb was over the Baltic while Hurricane Pablo was NE of the Azores W of Iberia. Dublin had 8.8h sunshine and it was a warmer day here with a maximum of 12.3C ( Milford Haven 13.4C Katesbridge -1.7C Bala -0.4 Cassley 37.0 mm Leconfield 8.9h Lake Vyrnwy 8.4h Valley 7.6h) [Max 12.3C Min 3.3C Grass -1.0C Pptn trace]. With pressure steady on 1027 mb after a cool night the 28th was another fine and mostly sunny day. Visibility was very good here in contrast to central and SE England where there was mist and fog. There was mist on Llyn Tegid, Bala. Pressure was high 1036 mb SW Iceland, N Africa 1020 mb and Black Sea 1021 mb. Pressure was low 997 mb at the Cap Nord, Norway. Hurricane Pablo was W of Cap Finisterre (Langdon Bay 14.2C Valley 11.5C Katesbridge -4.4C Fyvie Castle 9.4 mm Morecambe 9.2h Valley 8.5h ) [Max 9.5C Min 4.6C Rain nil]. Hardly a cloud in the sky to begin the 29th, a very fine if cool morning after heavy dew and a touch of ground frost. Pressure 1028 mb was rising with high 1035 mb situated between Iceland and Scotland. Ex-hurricane Pablo appeared to being absorbed into complex low-pressure 971 S Greenland losing its identity. A band of cloud and rain was encroaching the SW Approaches. A mostly sunny afternoon here the temperature rising to 10.1C; Valley was the sunniest place today with 9.0h. Breezy in the evening (Santon Downham 13.4C Hawarden 11.3C Kinbrace -5.0C Isles of Scilly 20.2 mm Valley 9.0h ) [Max 10.1C Min 3.5C Grass -0.3C Rain nil]. A cloudier morning than of late on the 30th, but it was mostly high level cirrus with some cumulus over the mountains. Contrails could be seen to the NE over Liverpool Bay. Heavy dew, but no overnight frost. There was a light ENE'ly breeze and the temperature reached 11.3C, warmer at Valley 12.4C with 4.2j sunshine (Kew Gardens 13.2C Valley 12.3C Resallach -5.6C Culdrose 19.4 mm Prestwick 8.4h Hawarden 5.0h) [Max 11.3C Min 5.4C Grass 1.6C Rain nil].

The 31st began brightly with some sunshine the sky clearing at 0900 GMT. There was a S'ly breeze with 4 okras of altocumulus lenticularis, cumulus and cirrus clouds. Pressure was steady on 1018 mb; the jetstream was fragmented at present. Pressure was high 1029 mb over the North Sea/ SE Baltic region while low-pressure 1007 mb was to the W over the Atlantic. An occluded front lay over Wales to the S of here and it was cloudy with mist and rain in S England and S Ireland. It was fine and sunny in East Anglia, N England and W Scotland. Not too bad here either, but the day was sunless at Valley (Camborne 15.3C Altnaharra -6.2C St Athan 18.0 mm Eskdalemuir 7.7h) [Max 13.4C Min 5.8C Rain 6.0 mm].

The month ended with a rainfall total of 165.0 mm (150%) & [128%] of averages, largest since 2014 ranking 14 in Llansadwrn records since 1928. The mean temperature was 10.5C (-0.9) & (-0.3) of averages, lowest since 2012. The provisional 95.7h sunshine at RAF Valley was most since 2017, ranking 38th dullest on the Anglesey record since 1931.


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November 2019

November - the 1st began dull and wet, one of those grey sky to ground days. Drizzle and slight rain in the morning here, although nothing was showing on rainfall radar. Pressure 994.7 mb was falling quickly with a depression 991 mb over Shannon, Ireland. A breezy afternoon the SW'ly wind gusting to 30 mph. There was heavy rain at 1900 GMT and further light to heavy rain through the night (North Wyke 16.9C Altnaharra -2.7C Killowen 33.6 mm Capel Curig 25.8 mm Stornoway 3.2h Valley 0.0h) [Max 13.7C Min 9.4C Rain 17.2 mm ]. Meteosat MSG image (c) EUMETSAT at 06 GMT on 2 November 2019, courtesy of Ferdinand Valk.The morning of the 2nd began much the same, dull with slight rain. Rainfall over the 24-h to 09 GMT was 17.2 mm falling over a 19h period. The wind had moderated and was a light SE'ly, the rain ceased by 0930 GMT. Pressure was 973 mb as the depression passed slowly over Anglesey, Low cloud and mist on the lower slopes of the Snowdonia Mountains slowly lifted, visibility was good. The afternoon had some light showers of rain and bright spells with glimpses of sunshine (Dunstaffnage 16.4C Lake Vyrnwy 5.3C Aberdaron 44.0 mm Dundrennan 4.9h) [Max 12.0C Min 7.6C Rain 0.8 mm]. Overnight some clear spells and at 07 GMT on the 3rd there was low fog over nearby fields. At 0900 GMT visibility was poor to moderate and the sky 6 oktas with some sunshine at times was beginning to cloud over with weak sunshine. Pressure 981 mb was rising in complex low-pressure over Britain, with low 973 mb Newcastle and 980 mb W of Ireland. Much of central England had mist and fog patches while it was sunny in London. There was a cool feeling to the day the temperature 8.1C, but rose to 12.9C later. Rain began in the late evening. Rough seas were reported impacting the western coastal areas of the Charente Maritime (Swanage 14.8C Kielder Castle 0.6C Craibstone 23.6 mm St Athan 6.4h) [Max 12.9C Min 6.8C Grass 2.6C Rain 6.4 mm]. The rain turned moderate to heavy in the small hours of the 4th, but had ceased by 0900 GMT. The sky had started to clear a and cloud was above the mountaintops with good visibility giving a clear view of the Carneddau Mountains where no snow was seen. The jetstream was established S of the British Isle over France and Iberia. Pressure 981 mb was rising within a large low with centre situated near Cork, Ireland, covering an area from Iceland to the Med. A cold front lay over France and the sea in Biscay was very rough indeed. There were showers in the vicinity, but here in the west the weather was best with Cardiff the warmest and Valley Anglesey sunniest places (Cardiff 13.6C Shobdon 2.2C Balmoral 32.0 mm Valley 4.4h ) [Max 10.1C min 6.7C Rain 3.4 mm]. On the 5th it was fairly bright with 6 oktas cloud cover at 0900 GMT. There was a force 5 N'ly breeze and this made it feel cool although the temperature was 9.3C. There was a convergence stretching over the North Channel, Irish Sea, Cardigan Bay, Scilly Islands to west of Brest. Pressure 1002 mb was rising quickly with a low 991 mb over Caen, France, moving south, introducing stronger winds and cooler air from the N. It was cold enough to have produced a little snow on Cairngorm Mountain this morning but, none in Snowdonia. Visibility was excellent in clean air especially in the afternoon with clear views of Llyn. The air temperature began to fall after 14 GMT and reached 5.5C at 2230 GMT. Thereafter the wind was light and blowing from the south-west (Cardiff 14.4C Kinbrace -0.4C Albemarle 21.6 mm Capel Curig 9.0 mm Loch Glascarnoch 5.6h ) [Max 10.1C Min 7.7C Rain 5.0 mm].

The 6th began overcast, after rain in the small hours, with moderately high cloud just above the summits of the Carneddau Mountains, but Yr Wyddfa on Snowdon a little higher was covered. Pressure 1004 mb was falling slowly and the sky was getting darker as the cloud thickened. We were in a fairly slack area of pressure between high-pressure 1-35 mb over the Atlantic and low-pressure E Baltic 992 mb. There was rain approaching from the W, but it kept dry until a slight shower in the middle of the afternoon until a spell of light to moderate rain arrived in the evening. There was a small 2.9 deg temperature range during the sunless day (Plymouth 12.7C Altnaharra 2.4C Min Loch Glascarnoch -4.6C Culdrose 21.4 mm Aberdaron 18.2 mm Lerwick 6.0h) [Max 8.4C Min 5.5C Rain 2.2 mm). A fine and bright morning on the 7th at first gave way to thickening cloud, spots of rain then slight rain by 11 GMT. Sferics were recorded near Dublin at 1130 GMT. A frontal-wave low had developed over Ireland, passing over North Wales pressure was lowest 989.8 mb at 0555 GMT here and at 0900 GMT was rising 991 mb. The low was then over central England 989 mb. There was an associated band of heavy rain to the N and E of here producing flooding in Yorkshire, Sheffield was badly hit again after 72.8 mm of rain had fallen. It was sunny in S England for a time, but cumulonimbus clouds with heavy showers were developing all along the S coast. Winds were strong to the W over the Atlantic, Biscay and Charente Maritime. During the evening as a frontal system passed over, preceded by heavy rain there was a sudden strengthening of the wind between 18 to 19 GMT from almost calm to 27 mph, this was associated with a rise in temperature from 5.1C to the day's maximum of 8.0C. The event was similarly recorded at Gorddinog and Gorwel Heights (Gosport Fleetlands 12.2C Magilligan -1.0C Sheffield 72.8 mm Porthmadog 25.6 mm Ross-on-Wye 7.1h Aberporth 3.0h) [Max 8.0C Min 4.7C Rain 8.4 mm]. A fine and sunny morning on the 8th and feeling fresher in the NNE'ly breeze. Fresh snow had fallen on the mountains above 2850 ft and elsewhere in Wales. Pressure 1011 mb was rising quickly with a complex low-pressure system SE England and France. High 1028 mb W of Iberia had a ridge to the W of Ireland and we were benefiting from this. The best of the sunshine was in Wales (Valley 8.1h sunniest place) and W Scotland. It was sunny all day here with solar radiation of 6.32 M and 8.1h at Valley. There was mist and fog in SE England (Scilly 11.9C Kinbrace -4.5C Gringley on The Hill 15.2 mm Bala 6.0 mm Valley 8.1h) [Max 9.5C Min 5.0C Rain 3.4 mm].

A colder night than of late with a touch of air and ground frost, but the sky was overcast and slight precipitation had been falling since 07 GMT on the morning of the 9th. Heavy precipitation fell at 0805 GMT, unidentified wet ice precipitation that did include marks typical of snow pellets was recorded by the hailometer, there was snow lying at 1000 ft on the Snowdonia Mountains and as low as 850 ft in places. At 0900 GMT slight rain was falling and visibility was moderate, but improving. The day continued dull and rather cold (Bude 10.9C Braemar -7.0C Murlough 40.0 mm Whitechurch 22.4 mm Manston 7.0h St Athan 0.9h)[Max 8.2C Min -0.4C Grass -4.4C Pptn 3.4 mm]. The 10th began very fine and sunny with a N'ly breeze and pressure 1017 mb was rising. There had been slight precipitation in the night, either side of midnight, when the air temperature was around 3.8C. Further snow had fallen on the mountains. Sunny, but in the afternoon moderately high cloud encroached this thickening by evening when there was a spell of rain from 1900 GMT (Cavendish 12.0C Altnaharra -7.5C Derrylin Cornahoule 11.6 mm Lake Vyrnwy 8.0 mm Shoeburyness 7.7h Hawarden 6.8h) [Max 7.9C Min 2.7C Grass -0.6C Rain 16.5 mm]. Precipitation continued after midnight on the 11th and around 01 GMT turned very heavy and included ice pellets falling at a rate up to 36 mm/h, the temperature falling to 3.4C. Showers continued these included snow pellets, the hail pad was marked by both ice and snow pellets (Swanage 11.2C Balmoral 2.4C Aviemore -0.7C min Threave 33.6 mm St Athan 6.0h) [Max 7.8C Min 3.4C Grass 1.5C Rain 1.5 mm]. A grey morning on the 12th with moderate rain and ice pellets falling at 0900 GMT just in time for the observer to get wet. Pressure 995 mb was falling quickly with low 983 mb over the N North Sea and an associated occluded front over the Irish Sea. Visibility was very poor in mist and rain. A sunless day and rather dark the highest solar radiation measured at 1340 GMT was only 163 W m -2 (Swanage 10.9C Braemar -2.8C Capel Curig 31.0 mm East Malling 5.2h) [Max 8.3C Min 5.0C Rain 7.2 mm]. On the morning of the 13th there had been a slight shower of rain just before 0900 GMT. A bright morning with a little weak sunshine appearing through mountain cloud of just 3 oktas mainly cirrus and cumulus. With the mostly clear sky overnight there had been a touch of ground frost (-1.1C). Pressure 999 mb was falling quickly with a low 989 mb over the S North Sea. Affecting the NW was low 989 mb S of Iceland and W of Scotland. An intermittent gentle S'ly breeze developed and the sky turned cloudier before noon, but it kept dry. Fresh snow had fallen on the Snowdonia Mountains as low as 2500 ft and in S Wales heavy snow resulted in a multi-vehicle accident and closure of a 12 mile section of the A470 in Powys between Merthyr Tydfil and Libanus (Hurn 10.8C Loch Glascarnoch -6.7C Whitechurch (Pembs) 20.2 mm Kinloss 6.3h) [Max 7.8C Min 2.2C Grass -1.1C Rain trace].

The 14th had another dull morning with moderately high cloud, but very good visibility. There was a fair amount of snow on the summits of the Snowdonia Mountains. Pressure 1002 mb was rising with a low 989 over S England and thunderstorms on the east Coast near Cranwell. Four sparrows were seen on the bird table today after being absent from the garden for some weeks going on their summer holiday around the local hedgerows. Perhaps the very cold NNE'ly breeze and the coldest day for a while (max 6.6C, lowest since 3 April 6.3C) played a part in their return. The red squirrels were also taking nuts from the feeders set up in the garden. Bright with some glimpses of sunshine in the afternoon, but breezy (Kew Gardens 10.5C Porthmadog 7.9C Low max Liscombe 2.0C Low min Dalwhinnie -8.1C Ross-on-Wye 42.8 mm Tredegar 41.8 mm Glasgow 7.2h Aberdaron 0.9h) [Max 6.6C Min 4.0C Rain 0.9 mm]. Much the same on the 15th with overcast sky, a grey to ground morning visibility was moderate to good, but improving. Dull and damp after recent showers it was feeling cold in the moderate N'ly breeze with a temperature of 6.5C. Low 996 mb was situated over Biarritz and covering a large area of France, the western Med (995 mb Verona) and (999 mb) N Africa where there had been snow on the Atlas Mountains. Snow had fallen also on Snowdon and was lying on the Carneddau above 2750 ft with 30% cover at 2500 ft (Walney Island 10.2C Strathallan -3.0C Capel Curig 21.6 mm Thomastown 6.1h St Athan 1.8h Valley 0.7h) [Max 8.4C Min 5.4C rain 0.3 mm].

The first 15-days of the month had 73.7 mm of rainfall (52%) & [58%] of averages. Temperatures were a little below average the mean 7.2C (-1.9) & [-0.5] of averages. The highest maximum 13.7C was 1.4 degrees below normal.

On the 16th low 1000 mb over Brittany, France, was still dominating the weather in SE Europe and N Africa. In Britain we had a minor ridge from the Azores high 1039 mb with pressure here 1009 mb rising; there was little benefit gained as cloud associated with the Brittany low resulted in a dull sunless day day on Anglesey. After a heavy shower in the night slight rain at first, then after a heavier shower mainly dry until the evening when there was more rain. Thermometers in the soil profile 5 cm to 100 cm deep all read <10C at 0900 GMT for the first time this season (Bude 10.7C Altnaharra -5.4C Chillingham Barns 15.0 mm Wittering 4.3h) [Max 8.2C Min 6.3C Rain 5.2 mm]. The weather was much the same on the 17th although the day did begin a little brighter. Cloud was just on the tops of the Snowdonia Mountains, there were a few breaks, and visibility was very good. Pressure 1013 mb was rising with an Atlantic-high 1024 mb W of Ireland. On the mountains broken snow lay above 2850 ft with the highest summits covered. It was a damp morning with little signs of the sky clearing Most of southern Britain was misty while Scotland was sunny in the S with showers in the north (Scolton Country Park 11.0C Braemar -4.7C Rhyl 23.4 mm Prestwick 6.1h Aberdaron 2.0h Valley 0.1h) [Max 8.9C Min 5.4C Rain 2.1 mm]. A fine and mostly sunny morning on the 18th after a touch of ground frost (-1.1C) with good visibility and a light N'ly breeze. Pressure was steady on 1019 mb, in a ridge from high 1026 mb Iberia, in a slack area between deep low 967 mb S Greenland and low 1003 mb Denmark. Quite a bright day with weak sunshine with some spells of sunshine in the afternoon (Milford Haven 11.3C Tulloch Bridge -8.6C Baltasound 5.4 mm Morecambe 7.8h Valley 7.1h) [Max 8.7C Min 2.5C Grass -1.1C Rain nil]. A colder night as starting with clear skies the air temperature went down to 0.6C and there was a moderate ground frost -3.5C. The sky had clouded over, there was a pink colouration after dawn, then a grey sky and with a SE'ly breeze with orographic waves at 0900 GMT on the 19th. Visibility was very good, fog around the coast had cleared, but mist and fog persisted for a while in central England. Snow was lying on the mountains above 2750 ft with some as low as 2250 ft in places. There was some weak sunshine in the morning, slight showers of rain and glimpses of sunshine in the afternoon before turning dull with a strengthening breeze in late afternoon and rising temperature through the night(Armagh 11.4C Milford Haven 10.9C, Braemar -9.9C Ballypatrick Forest 11.4 mm Weybourne 6.3h Bala 1.3h) [Max 10.1C Min 0.6C Grass -3.5C Pptn trace].

The sky was overcast on the morning of the 20th, but fine and dry. There was a moderate SE'ly breeze and the temperature recently 10.1C was 9.9C the breeze at 76 % RH was drying the leaf litter in the wood and grass was dry also. Pressure was on 1007 mb and starting to fall with a low 989 mb W of Shannon and a high 1027 mb S Norway moving north. Unsettled in the Mediterranean with low 1009 mb over the Adriatic Sea. It kept cloudy here, but the Midlands and East Anglia were sunny. The temperature fell slowly during the day reaching 5C about 20 GMT. The day was sunless. It was very windy in Llanfairfechan during the evening, the SE'ly wind off the mountains was gusting to 41 mph at Gorwell Heights at 2140 GMT and 53 mph at Gorddinog at 2220 GMT (Scilly 11.9C Valley 10.5C Redesdale Camp -4.1C Cardinham 27.4 mm East Malling 4.8h Valley 0.0h) [Max 9.9C Min 6.2C Rain nil]. The light SE'ly persisted through the night with the temperature hovering around 5C dropping only to 3.7C around 07 GMT on the 21st when there was a touch of ground frost under some clear sky. At 0900 GMT the temperature was 5.7 with 72% RH and concrete and grass were dry. In Llanfairfechan the strong SE'ly wind off the mountains was persisting and at Gorwel Heights there was a gust of 37 mph at 0500 GMT, at Gorddinog 53 mph was recorded at 0750 GMT . Very fine with altocumulus lenticularis clouds to the S of the station, haze hung low over the Menai Strait and there was a little sunshine before cloud increased for the day later thickening. A dry day with just a little dampness in the air towards dusk and early evening (Scilly 12.0C Ravensworth -2.8 C Plymouth 22.0 mm Dundrennan 3.8h Aberporth 0.4h) [Max 7.4C Min 3.7C Pptn trace]. A bright morning on the 22nd with cloud decreasing at 0900 GMT. Two curious buzzards flew low over me while making observations at the screen, their flypast at treetop height is a regular thing, but today they were lower. With an E'ly breeze lenticula clouds were evident together with cirrus and cumulus. A fine day with sunny spells here, Valley reported light rain showers in the afternoon (Swanage 12.0C Milford Haven 10.1C Drumnadrochit -0.3C Dunkeswell 24.6 mm Tiree 2.4h Valley 2.4h) [Max 9.5C Min 4.1C Rain 1.6 mm].

On the 23rd there was a deep Atlantic-low complex 984 mb off the Gironde giving bad weather to the Charente Maritime. There was an occluded front over the Celtic and Irish Sea and this gave us a dull, sunless and wet day. At 0900 GMT it was raining slightly and visibility was very poor, pressure 995 mb was rising. Late in the afternoon there was a clearance in the west, but it did not reach here (Plymouth 12.8C Drumnadrochit 1.3C Exeter 28.2 mm Mumbles Head 20.4 mm Bude 0.9h) [Max 8.8C Min 5.7C Rain 2.4 mm]. It was another day of dull misty weather almost everywhere on the 24th so we were not singled out for having it. Pressure was steady on 1002 mb with an Atlantic-low 978 mb off SW Ireland and an associated occluded front over the Irish Sea. Extra-tropical cyclone Sebastien downgraded from a tropical storm to an extra-tropical storm N of the Azores and was heading towards the UK. It was mild 7.9C and 95% RH at 0900 GMT and there was very little wind just an air from the SSE indicated by smoke drift. The day was sunless. Bad weather continued in France, low 998 mb was over Sardinia and there was serious flooding in S France (Hurn 13.8C Gogerddan 13.6C Altnaharra 0.5C Aberdaron 19.6 mm Kinloss 3.1h) [Max 9.8C Min 6.7C Rain 3.4 mm]. The dull, wet and mild weather continued on the 25th as low 989 mb near Shannon had an occluded front over the Irish Sea. A dismal day, very damp, it seemed to be raining most of the time (9 wet hours recorded), but the cloud did lift a little in the afternoon (no sunshine) to reveal that a few small snow patches were surviving the mild 5C conditions on the mountaintops (Pershore College 14.6C Cardiff 14.2C Aviemore 4.3C Craibstone 22.6 mm Whitechurch 17.2 mm Bude 3.0 h) [Max 12.6C Min 7.9C Rain 6.0 mm].

The 26th began rather misty with moderate visibility after early rain. It was mild the temperature at 0900 GMT 9.1C; most snow had meted on the mountains, but there were some snow patches remaining. Pressure 988 mb was falling with a depression 971 mb near the Fastnet Rock SW Ireland and an occluded front over S Wales. There were strong winds around the English Channel with he Isles of Scilly reporting a gust of 51 mph. Although it was quiet in Llansadwrn with a force 3 ESE'ly it was more lively in Llanfairfechan with a gusts of 36 mph recorded at Gorwel Heights and 40 mph at Gorddinog. Little in the way of sunshine today (Pershore 14.6C Aviemore 4.3C Craibstone 22.6 mm Bude 3.0h Valley 0.5h) [Max 12.4C Min 7.7C Rain 7.2 mm]. A grey day dawned on the 27th with slight rain and drizzle. Earlier rain had been moderate to heavy. Rain petered out by 10 GMT, but mist was lingering and there was for in parts of NE England, and Tayside Scotland. Pressure was steady on 984 mb with low 977 mb over the Severn Estuary tracking ENE to be over Lincolnshire at 18 GMT. The sky brightened before noon when there were some glimpses of sunshine (St James Park 12.7C Drumalbin 0.7C Charsfield 23.4 mm Whitechurch 16.8 mm Dundrennan 5.7h Valley 0.7h) [Max 9.2C Min 7.9C Rain 0.8 mm]. Another grey day on the 28th with a fine drizzle under low cloud. Continuing mild with 8.2C at 0900 GMT 97% RH. Soon we had a shower of rain the beginning of a wet sunless day (Swanage 12.4C Kinbrace 1.1C Chillingham Barns 23.0 mm Tiree 5.0h) [Max 8.9C Min 5.0C Rain 2.9 mm].

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In contrast the 29th dawned clear and frosty with extensive white frost, and very good visibility. Pressure 1017 mb was rising quickly with highs 1026 mb Iceland and Greenland with a ridge to the Irish Sea and Anglesey. There was a cold front over the Severn Estuary stretching eastward to Thanet. With complex low 981 mb over the Baltic cold air was being drawn down over the North Sea. Low temperature on the Snowdonia Mountaintops had produced extensive frost to low levels and icing as low as 2000 ft that looked like snow in the morning sunshine, the icing persisted for several days (Scilly 12.0C Low max Bala 0.7C Low min Tyndrum -6.0C Fylingdales 7.6 mm Scolton 1.8 mm East Malling 7.5h Aberdaron 7.2h Valley 6.9h) [Max 8.1C Min 1.0C Grass -3.4C Pptn nil]. A cold mostly clear night producing extensive frost with silver frost on the morning of the 30th with the grass minimum down to -3.6C. but no air frost here. Hardly a cloud in the sky at 0900 GMT and very good visibility the mountaintops still covered with ice and frost. A lovely sunny day here, but wet and windy in the Scilly Isles, SW England and The Isle of Wight. Fog again affected central and SE England (Scilly 11.2C Balmoral -3.3C Min Tyndrum -9.7C Scilly 11.6 mm Morecambe 7.1h Valley 6.7h) [Max 7.8C Min 0.4C Grass -3.6C Pptn trace].

The month ended with a rainfall total of 105.6 mm (74%) & [84%] of averages, largest since 2014 ranking 33rd lowest in Llansadwrn records since 1928. The mean temperature was 7.1C (-2.0) & (-0.6) of averages, lowest since 2016. Provisional sunshine at RAF Valley was (48.9h) lowest since 2017, ranking 27th dullest on the Anglesey record since 1931.


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December 2019

December - the 1st began with an extensive white frost on grass and fallen leaves, the grass minimum thermometer was also coated and read -3.4C. There was no air frost the lowest reading being 0.4C in the Stevenson screen. There was mist in valleys and hollows, the Menai Strait and around some parts of the coast. Here it was clear, cloud cover at 2 oktas was increasing with some cumuli to the NE and recently over the mountains. It was sunny in SE England, East Anglia and Scotland, but Tayside was foggy. Pressure 1028 mb was rising with pressure high 1030 mb over the Atlantic to the NW. A pleasant mostly sunny day (Scilly 9.2C Porthmadog 8.1C Tulloch Bridge -10.3C Resallach 12.2 mm Morecambe 6.9h Lake Vyrnwy 6.6h Valley 5.8h) [Max 6.3C Min 0.4C Grass -3.6C Pptn nil]. A fine and fairly bright start on the 2nd with weak sunshine then glimpses of the real thing before cloud encroached from the N resulting in a cool damp morning with some spots of drizzle. Disappointing considering the high pressure 1034 mb here in the Atlantic-high 1035 mb to the SW centred near the Fastnet Rock. It was sunny elsewhere central England, East Anglia and the East Coast, but there was rain in Scotland (Kinlochewe 10.9 C Lowest maximum temperature Llysdinam 0.9 C Lowest minimum temperature Shap -7.3 C Highest rainfall Resallach 27.6 mm Sunniest East Malling 7.2 h) [Max 7.4C Min 0.9C Grass -3.2C Rain nil]. A fine and bright morning on the 3rd with the sky clearing towards 0900 GMT. Liked by one of the red squirrels, this one actually coloured charcoal grey, taking nuts from a feeder nearby. Pressure was on 1028 mb and visibility moderate to good with a light SW'ly breeze. Mist and fog in parts of southern Britain, sunny in the N, NE and East Anglia. A sunny afternoon (Mumbles Head 11.1C Hurn -2.2C Lerwick 3.8 mm East Malling 7.6h Hawarden 6.7h) [Max 8.9C Min 3.1C Grass -0.8C Rain trace]. Another fine morning on the 4th with little cloud at first, but soon increasing. There was a moderate to strong S'ly wind and the Snowdonia Mountains had a roll of cloud along the tops. The sky here was mostly cloud covered by 1130 GMT, but it remained sunny for longer at the Great Orme and Llandudno. Rain arrived in the middle of the afternoon turning light to moderate at times (Milford Haven 11.9C Benson -4.4C Achnagart 23.6 mm Shoeburyness 7.1h Hawarden 6.6h) [Max 8.8C Min 5.9C Rain 2.2 mm]. There was a vivid red sky over the mountains when the sky above the Carneddau was clearer. Now at 0900 GMT on the 5th low cloud in the W had descended and rain was in sight. Pressure 1016 mb was falling. The high of previous days had sunk S and was 1032 mb over the Azores with a declining ridge to Brest. Frontal cloud associated with low 977 mb was strung out along western Britain. A wet and sunless day (Rhyl 13.9C Low max Lerwick 5.3C Low min Lerwick 3.9C Sennybridge 28.8 mm Sheffield 1.7h) [Max 10.7C Min 3.7C Rain 6.0 mm].

The 6th began overcast with intermittent showers and drizzle, a wet and windy morning. At 0945 GMT some breaks appeared in the cloud, but improvement was short lived, thick cloud and rain showers soon returned (Rhyl 13.9C Lerwick 3.9C Sennybridge 28.8 mm Sheffield 1.7h Hawarden 1.0h) [Max 10.6C Min 7.3C Rain 3.7 mm]. AWS rainfall record 24h to 09 GMT on the 8th.Pressure 1012 mb was steady on the morning of the 7th, but Storm Atiyah 969 mb was approaching from the north-west soon began to fall. With skies overcast the wind strengthened in the afternoon becoming very strong by evening. Valley reported S'ly gales at 20 GMT and Capel Curig a gust of 61 mph, 38 mph here, 47 mph at Gorwel Heights. There was moderate to heavy rain (10.8 mm/h) during the evening in warm sector air; the temperature rising to 11.4C at 0030 GMT. The temperature fell on a cold front passing around 01 GMT with pressure 993 mb at its lowest. Rainfall 09--09 GMT was 15.5 mm over 13h duration; Gorwel Heights 10.0 mm. At midnight Atiyah was 963 mb between Scotland and Iceland and here 1010 mb rising rapidly. (Achnagart 13.3C Hawarden 12.6C Aboyne -0.8C Achnagart 54.4 mm Capel Curig 6.0 mm Wittering 3.6h ) [Max 11.4C Min 6.5C Rain 15.5 mm] [Eskdalemuir 30 mm Tiree 28.2 mm Valley 8.4 mm].

On the 8th pressure 996 mb was falling again as a very deep complex low 956 mb low-pressure system Storm Atiyah stretched from Greenland to the Baltic including Britain. A fresh W'ly breeze with gusts of 33 mph here resulted in rough seas around the coastline and 55 mph at Capel Curig There were thundery showers in the vicinity, one or two heavy, including one at 1330 GMT at Penhesgyn. Later sferics were recorded near Liverpool. Atiyah was off the Western Isles 970 mb at 1800 GMT and moved rapidly to the North Sea off Wick at midnight. (Hurn 11.7C Braemar 1.5C Cassley 48.6 mm Capel Curig 36.8 mm Boulmer 5.4h ) [Max 7.8C Min 6.3C Rain 2.8 mm]. There was a spell of light to moderate rain from 2300 to 0100 GMT on the 9th pressure 987 mb was at its lowest at 0037 GMT, the wind which had been moderating soon veered N-NE'ly. At 0900 GMT pressure 1013 mb was rising rapidly and it was a bright fair morning with a NNE'ly breeze. High 1033 mb was over the Atlantic off Iberia with a ridge to the W moving across here. The Norwegian Sea was packed with marine convection. A fine and sunny day, but there was more bad weather S of Greenland heading our way courtesy of the jetstream (Swanage 11.4C Tyndrum 0.3C Capel Curig 20.0 mm Wellesbourne 6.6h Valley 5.5h [5.7h] ) [Max 9.8C Min 5.5C Rain 2.4 mm]. It was a wet and windy day on the 10th with strong to gale SSW'ly winds. Gusting to 46 mph here, 58 mph at Gorwel Heights and 63 mph at Capel Curig a branch was blown off a horsechestnut tree about 1030 GMT blocking the drive to Gadlys. Warm sector air the temperature rising to 12.0C at 1447 GMT just before the arrival of a cold front. Moderate to heavy rain in the afternoon, a shower of snow pellets about 17 GMT with the temperature falling to 5.5C by 1855 GMT; a sunless day (Bude 14.2C Topcliffe -4.3C Tyndrum 69.0 mm Capel Curig 57.0 mm East Malling 0.3 h Valley 0.0h) [Max 12.0C Min 2.5C Grass -1.9C Rain 14.2 mm].

There were some clear spells overnight, but the morning of the 11th was a mostly cloudy one. Unidentified ice precipitation was recorded with snow pellets and there was a fresh fall of snow on the Snowdonia Mountains above 2500 ft. Pressure 1000 mb with a low 949 mb SE Iceland traversing the N of Scotland to the Norwegian Sea. There were cumulus clouds in the vicinity these developing during the morning into towering versions later with the odd cumulonimbus in the eastern mainland. Fine, cooler some slight showers with sunny spells in the afternoon (St Catherine's Point 9.7C Mumbles Head 7.9C Alice Holt Lodge -0.7C Aviemore 30.0 mm Weybourne 5.8h Aberdaron 2.2h ) [Max 6.9C Min 4.3C Pptn 4.8 mm]

More in prep...

The first 15-days of the month had 83.2 mm of rainfall (52%) & [69%] of averages. The highest maximum 12.0C was 0.5 degrees below normal. There were 6 days with ice precipitation of various sorts, but no snow.

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Dates of first flowering snowdrop  in the garden in Llansadwrn winters 1996-2020. The first snowdrop of the winter/ spring 2019 makes an appearance in the garden.> The last day of the year the 31st began brightly with a light NNE'ly breeze and a little sunshine. Cloud was spilling over the tops of the Snowdonia Mountains where there were a few snow patches just about surviving the mild weather. The sky was clearing a little and there was some sunshine later. The first appearance of an open snowdrop flower was recorded in the garden on the 31st December (graphic left). The date is recorded when a flower is fully developed (right), low green shoots with white tips have been seen for a while. Flowering 7 days later than last winter (1918/19), 6 days before the median date on 5 January, it was the fifth earliest appearance on record (Bude 12.6C Rhyl 11.9C Santon Downham -2.3C Resallach 17.8 mm Mona 0.6 mm Shoeburyness 7.1h Hawarden 6.2h Valley 2.7h) [Max10.4C Min 4.8C Grass 1.0C Rain trace].

 

The month ended with a rainfall total of 100.9 mm (63%) & [84%] of averages, lowest since 2018 ranking 33rd lowest in Llansadwrn records since 1928. The mean temperature was 6.7C (+0.5) & (+1.4) of averages, highest since 2014. Provisional sunshine at RAF Valley was (48.9h) lowest since 2017, ranking 27th dullest on the Anglesey record since 1931.

The year ended with a total rainfall of 1223.8 mm (107%) & [113%] of averages, largest since 2017. The wettest month was March with 174.1 mm and the driest May with 39.1 mm. The annual mean temperature was 10.7C (+0.2) & [+0.4] of averages highest since 2014. The warmest month was was July with a mean 16.7C [(+1.0)] of averages and the coldest January with a mean 5.3C [(+0.2)] of averages. The highet daily temperature was 30.6C on the 28th of June and the coldest -2.4C on the 31st January. There were 6 days with air frost and 64 days with ground frost..

 

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