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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September 2019

September - The month began on a bright and breezy note. Pressure 1018 mb was rising with a low 984 mb E Norwegian Sea and a high 1028 mb W FitzRoy influencing our weather. We had a cooler W/NW flow of air and at 0900 GMT a moderate W'ly breeze. The temperature was 13.1C rising to 17.6C in the early afternoon (Frittenden 21.8C Topcliffe 5.3C Resallach 31.2 mm St Athan 12.0h) [Max 17.6C Min 8.6C Grass 5.4C Rain 0.2 mm]. A similarly bright morning on the 2nd with a moderate SW'ly breeze. Six oktas of cumulus cloud cover that was increasing. Pressure was steady on 1022 mb with an Atlantic- high 1029 mb off Cap Finisterre. A frontal-wave low 1005 mb was W of Scotland with warm fronts lying to the N of Anglesey; a rather wet day and little in the way of sunshine. Slow-moving hurricane Dorian category 5 hit the Bahamas in the Caribbean reported to be the strongest recorded there causing much devastation and loss of more than a thousand lives. Picking up again it was tracking towards Florida. In the event it headed N towards Canada and Nova Scotia where it caused more damage (Heathrow 23.6 Lerwick 12.3C, Aboyne 0.0C, Achnagart 42.2 mm, East Malling 10.4 h) [Max 17.2 Min 10.1 Grass 6.4C Rain 3.4 mm]. The 3rd dawned dull with over cast skies and there was early drizzle and light rain. Then dry, but keeping dull and sunless, the evening was wet from 1930 GMT with heavy rain just before 21 GMT (falling at a rate up to 23 mm/h) (Cavendish 24.2C Hawarden 21.1C Kinbrace 3.5C Eskdale Muir 22.8 mm Capel Curig 17.2 mm Wittering 8.9h ) [Max 16.1C Min 13.1C Rain 11.4 mm].

4th: (Shoeburyness 21.3C Cardiff 18.3C Aboyne 4.4C Harris Quidnish 33.8 mm Gogerddan 10.8 mm Camborne 9.2h Aberdaron 7.4h) [Max 17.2C Min 9.7C Rain 0.2 mm]. 5th: (St. James Park 19.4C Warcop 2.1C Harris Quidnish 13.0 mm Shoeburyness 11.9h Aberdaron 10.3h) [Max 17.3C Min 8.5C Rain 0.4 mm]. 6th: (Pershore 21.2C Frittenden 4.0C Achnagart 32.8 mm Sennybridge 9.8 mm Charterhall 7.1h Lake Vyrnwy 4.6h) [Max 18.0C Min 12.1C Rain nil]. 7th: (Usk 20.1C Tulloch Bridge 3.7C Aviemore 2.4 mm Prestwick 12.2h Aberdaron 7.6h) [Max 17.6C Min 10.7 Rain nil]. 8th: (Plymouth 19.6C Cardiff 19.2C Aboyne -1.6C Tiree 4.8 mm Odiham 11.5h St Athan 10.6h) [Max 16.8C Min 7.4C Grass 4.8C Rain 17.8 mm]. 9th: A burst of rain between 1530 - 1700 GMT fell at a rate up to 18 mm/h. (Murlough 18.0C Milford Haven 17.3C Santon Downham 1.6C Chivenor 35.6 mm Sennybridge 28.0 mm Lerwick 10.8h) [Max 15.9C Min 11.6C Rain 2.4 mm].

10th: Dull and cool at first with air minimum of 9.1C at 0614 GMT. Pressure 1021 mb rising slowly the temperature rising to 12.2C at 0900 GMT. High 1029 mb was near the Azores with a ridge to SW Ireland and the Irish Sea. Low 1023 mb was near Bordeaux; in the Charente Maritime also clear early with a temperature of 7.4C it soon turned cloudier, but cleared up again in the afternoon when sunny the temperature rising to 16.5C. Bright and sunny on Anglesey with fair-weather cumuli in the afternoon. The SW'ly strengthened through the day. A warm front associated with low 983 mb S of Iceland lay over the Irish Sea at 18 GMT; the temperature 12.5C rising with light to moderate rain from 2300 GMT (Heathrow 21.9C Cardiff 19.5C Min Katesbridge 0.3C Tiree 21.2 mm Mona 8.2 mm Camborne 8.5h Aberdaron 7.5h Valley 6.2h) [Max 16.5C Min 9.1C Grass 6.6C Rain 5.8 mm] .

The wind continued to strengthen after midnight on the 11th until 03 GMT with the temperature rising to 15.7C. A cold front passed over the Irish Sea with heavy rain falling at up to 30 mm/h at 0349 GMT and 5.6 mm was recorded by the gauge at 0900 GMT. The wind had moderated and pressure 1016 mb was rising after reaching a low of 1013 mb at 0334 GMT. The sky was clearing and there was a rough sea running around the coast. Dry with sunny spells in the afternoon (Bedford 24.6C Usk 21.3C Min Houghton Hall 8.5C Achnagart 22.8 mm Sennybridge 15.6 mm Aberdaron 8.5h) [Max 18.7C Min 12.1C Rain 0.4 mm]. At 06 GMT on the 12th a frontal-wave low 1015 mb over Shannon, Ireland, was tracking towards N England. Pressure here at 0900 GMT 1023 mb was rising slowly. With a warm front over the Irish Sea it was cloudy and breezy morning with slight misty rain, a little brighter at 11 GMT before thickening again giving a sunless day. Showery rain at the end of the afternoon as a cold front passed over at 1700 GMT producing a cyclonic wind (Cavendish 26.8C Santon Downham 6.1C Fair Isle 13.6 mm Capel Curig 12.2 mm Shoeburyness 9.4h) [Max 16.8C Min 13.4C Rain 2.6 mm].

A bright start on the 13th with the high-pressure 1037.5 mb at 0900 GMT within high 1038 mb S Ireland and and Wales. Convective clouds developed in the afternoon with convergence SW-NE breezes at the weather station with short sunny spells; the maximum temperature was 17.6C at 1448 GMT. A dry day. Storms developed over the Balearic Islands and Spain where a tornado was reported (Gosport Fleetlands 23.1C Katesbridge 0.2C Cassley 9.4 mm Lyneham 12.3h) [Max 17.6 Min 8.0C Rain nil]. Pressure remained high 1033 mb on the 14th, but was falling as the elongated high 1036 mb, over Belgium extended to Wales and southern Britain, weakened. At 0900 GMT the temperature was 15.2C rising to 18.6C. Wet in Scotland, warm in the south of England (Heathrow 24.0C South Newington 0.8C Kinlochewe 50.6 mm Lyneham 12.2h Aberporth 12.0h) [Max 18.6C Min 8.2C Rain 0.2 mm]. A dull and damp morning on Anglesey on the 15th with rain falling in the north of the island. Pressure was on 1026 mb, but a slow-moving cold front over N Wales and NE England made for a miserable day. Overcast with drizzle at times through the morning, thinner cloud around noon, thickening in the afternoon with a spell of light to moderate rain from 17 GMT as a band of rain, with a cold front associated with low 982 mb over the Baltic, over N Wales. The temperature at 1720 GMT was 11.7C, but this was to rise to 14.1C at midnight. South of the frontal cloud the day was sunny and warm (St James Park 26.9C Usk 23.3C South Newington 3.4C Mona 8.2 mm Manston 11.8h St Athan 2.9h Valley 0.0h) [Max 13.9C Min 12.9C Rain 17.4 mm].

The first 15-days of August had 62.2 mm of rainfall (63%) & [66%] of averages. Temperatures were a little below average the mean 13.7C [-0.1] of the 1981-2010 average. The highest maximum 18.7C was 3 degrees below the decadal avarage.

Rain continued after midnight on the 16th petering out by 01 GMT, but remained drizzly to daybreak. Yesterday's band of cloud over Wales and central Britain was still hanging around in the morning and was slow moving S or to disperse. The temperature had risen to 16.1C at 1445 GMT then, as the cold front began to move off, to fall to 8.6C just before midnight (Cardiff 21.7C Kielder Castle -0.1C Sutton Bonington 12.0 mm Trawsgoed 9.8 mm Morecambe 10.3h) [Max 16.1C Min 11.7C Rain nil]. It was a dry and bright morning on the 17th with pressure 1028 mb rising within an Ireland/ Britain high 1030 mb. There was a little cloud over the mountains with very good visibility. Sunny at times continuing on into the evening which was fine and clear on Anglesey with a little cloud remaining over the Carneddau (Gosport Fleetlands 20.9C Katesbridge 0.5C Baltasound 2.8 mm Lyneham 11.8h St Athan 10h Gosport Fleetlands 20.9 C Lowest maximum temperature Loch Glascarnoch 10.6 C Lowest minimum temperature Katesbridge 0.5 C Highest rainfall Baltasound 2.8 mm Sunniest Lyneham 11.8 hoursalley 9.7h) [Max 17.3C Min 8.4C Rain nil]. Another dry and sunny day on Anglesey on the 18th with the jetstream well to the N pressure 1032 mb here was still rising within an Anglesey/ Wales/ UK high 1032 mb. Cool overnight the air minimum down to 7.3C, lowest of the month and lowest since the 6.6C on 10 June. Very good visibility with a light N/ NE'ly breeze through to evening that was clear with just a little haze. Cloud edged S over Scotland over N England and NE Wales by evening. Sunshine at Valley today 11.6h was the highest of the month (Killowen 21.7C Usk 20.8C Min South Newington 0.2C Sennybridge 2.4C Cassley 19.2 mm East Malling 12.2h Aberporth 12.0h Valley 11.6h) [Max 19.1C Min 7.3C Grass 5.0C Rain nil]. At midnight on the 19th the Meto synoptic chart gave the centre of the high as Anglesey. Early in the morning there were patches of fog around the coastline and in the Menai Strait. At 0900 GMT pressure was 1032.5 mb within the British high centred over the Welsh Borders, it's not often one can say that especially in September, dominating the weather in France as well. Low 995 mb S of the Denmark Strait was having no influence at all on the weather here Another fine sunny day (Coton-in-the-Elms 22.5C Santon Downham 1.5C Kirkwall 2.8 mm Bala 0.2 mm East Malling 12.2h Aberdaron 11.8 h Valley 11.6h) [Max 20.9C Min 8.3C Grass 5.3C Pptn 0.1 mm]. Well, much the same on the 20th although pressure 1025 mb had declined a little as our high moved SE over Europe. In the wings to the W were several low-pressure systems 992 mb with a thick band of cloud S of Iceland and W of Shannon, Ireland. It did not make any difference here today; very fine and sunny all day with the temperature rising from an overnight low of 11.1C to 23.6C (Kinlochewe 25.3C Lo max Fair Isle 14.4 C Min Tulloch Bridge -0.3C Wych Cross 0.2 mm East Malling 12.0h Aberporth 11.9h Valley 11.4h) [Max 23.6C Min 11.1C Rain nil]. Very fine again with mostly clear skies over Britain on the 21st the temperature 18.6C here at 0900 GMT rising to 26.2C in the afternoon, highest in September since 26.4C in 2011 and 28.0 in 2005. Relative humidity was down to 47% at 1210 GMT in the Föhn-like SSE'ly breeze. Valley reported a maximum temperature of 27.4C (53% RH) in a SE'ly breeze, provisionally highest maximum in the UK. Cooler in Llanfairfechan, Gorwel Heights 24.7C and Gorddinog AWS 26.1C (Valley 27.4C Mona 26.1C Braemar 0.5C Whitechurch, Pemps. 12.6 mm Kinloss 11.7h Hawarden 10.9h Valley 9.4h) [Max 26.2C Min 11.6C Rain nil].

By the 22nd the weather had changed. Pressure had fallen to 1009 mb as low 978 S of Iceland introduced a band of cloud associated with a frontal-waves triple-point NW of Ireland. A cold front lay from Pembrokeshire over the Charante Maritime, France. there were numerous shower troughs were developed over Britain while high 1023 mb was over the Pyrenees. Thunderstorms developed in N England and Manchester Airport early in the day. The day was mostly cloudy here, with showers around noon, a glimpse of sunshine around 13 GMT and further showers around 16 GMT; it was cooler than of late (Weybourne 27.7C Lo max Lerwick 11.1C Min Braemar 0.7C Derrylin Cornahoule 39.8 mm Lake Vyrnwy 11.8 mm Tibenham Airfield 7.3h Aberporth 4.3h Valley 1.8h) [Max 19.1C Min 16.9C Rain 1.2 mm]. As pressure 1007 mb continued to fall at 0900 GMT on the 23rd the sky was mostly clear over Anglesey at first, after a recent shower, although the Snowdonia Mountains were cloud covered. There was a band of rain over S Ireland and Cornwall on a warm front associated with low 975 mb S of Iceland. There was showery rain in the afternoon with little in the was of sunshine (Lossiemouth 21.5C Porthmadog 18.7C Exeter 7.4C Capel Curig 22.8 mm Waddington 6.5h Valley 2.6h) [Max 17.4C Min 11.1C Rain 6.2 mm]. On the 24th there were storms affecting S Wales and the English Channel on a cold front associated with the low 984 mb near Shannon, Ireland, Pressure here had bottomed out at 996.9 mb at 0828 GMT. There was light to moderate rain here the temperature 15.4C (dewpoint14.3C). In heavy rain there was a landslide in S Wales and flooding in Aberdare. Although pressure was still falling, and it was breezy, the afternoon cleared up and there was some sunshine. The temperature rose to 17.7C, before more showery rain fell after 17 GMT (Kinlochewe 22.3C Cardiff 19.3C Aboyne 5.4C Boscombe Down 55.8 mm Tredegar 40 mm Katesbridge 4.9h) [Max 17.7C Min 14.2C Rain 2.4 mm]. On the 25th pressure 999 mb was rising with the remnants of H Humberto now 995 mb central England. The sky was grey and overcast on Anglesey, but there was brightness E of the Carneddau Mountains and in the afternoon the cloud broke up and there were glimpses of sunshine. From 15 GMT pressure was falling again; there was a spell of moderate to heavy rain from 2100 GMT to midnight (Heathrow 22.2C Katesbridge 5.5C Okehampton 33.4 mm Trawsgoed 20.4 mm Stornoway 4.8h) [Max 16.9C Min 11.8C Rain 10.2 mm]. The wind freshened as pressure continued to fall after midnight on the 26th reaching a low of 995 mb at 03 GMT. Complex low 984 mb was S of Iceland and W of Scotland with a shower trough over the Irish Sea and a cold front over central England, the Channel and NW Brittany. A strong SW'ly wind persisted through the mostly cloudy day only moderating during the evening (Santon Downham 21.5C Lerwick 12.2C Altnahinch Filters 9.8C Lake Vyrnwy 37.0 mm Shobdon 7.0h) [Max 16.4C Min 12.2C Rain 6.6 mm] .

A wet and windy morning on the 27th and it was raining at 0900 GMT pressure reaching a low of 994 mb. Low 989 mb SE Iceland had an associated shower trough over Wales. The temperature was 13.7C and varied through the day in showers reaching its highest 14.6C at 1513 GMT There was little in the way of sunshine the day was dull with blustery spells of moderate to heavy rain heaviest up to 75 mm/ h falling briefly at 1250 GMT (Santon Downham 19.1C Lo Max Salsburgh 12.2C Altnaharra 2.9C Lake Vyrnwy 51.2 mm Shoeburyness 5.1h) [Max 14.6C Min 12.2C Rain 15.4 mm]. A windy day on the 28th with gusts up to 45 mph at Aberdaron. Wet and windy on Anglesey, heavy over the Snowdonia Mountains. Llyn Tegid at Bala was overflowing flooding the car park at the visitor centre Complex low-pressure 996 mb charted over the British Isles, pressure here 1005 mb soon began to fall. A dull day with a spell of moderate to heavy rain overnight from 1830 GMT (Manston 20.9C Strathallan 3.3C Scolton Country Park 34.0 mm Charterhall 8.9h) [Max 15.6C Min 11.5C Rain 16.8 mm]. The wet and windy weather continued on the 29th with a depression over Anglesey, pressure was at its lowest 989 mb on an occluded front at 0616 GMT rising quickly 991 mb at 0900 GMT. The temperature at 0534 GMT was 15.6C the maximum of the 29th. The temperature at 0900 GMT was 12.6C rising to 14.7C in the afternoon. In a strong N'ly wind and high tide just before noon the sea was pounding the shore at Llanfairfechan damaging the sea defences. The lake at Bala was still overflowing with the visitor centre car park flooded. The day was dull with mist and slight rain or drizzle throughout (Weybourne 20.8C Tyndrum 4.1C Stonyhurst 51.8 mm Capel Curig 45.0 mm Aberdaron 4.2h) [Max 14.7C Min 11.2C Rain 1.4 mm]. The sky was almost clear before dawn, but cloud soon appeared so that at 0900 GMT there were 7 oktas cover. It was misty around the coast and low lying fog was in the Menai Strait. Water in Llyn Tegid was beginning to recede exposing more of the visitor centre car park. The day kept dull with a band of heavy rain in the afternoon ceasing before midnight. The rainfall for the 24h (09-09 GMT) was 24.2 mm, largest of the month Mona, Anglesey [22.4 mm] and Valley [22.6 mm]. Wet in Snowdonia with Capel Curig reporting [43.8 mm] and Lake Vyrnwy [35.4 mm] (Thorney Island 19.0C Katesbridge 2.7C Capel Curig 34.6 mm Lerwick 6.5h) [Max 14.2C Min 9.2 mm Rain 24.2 mm].

The month ended with a rainfall total of 146.7 mm (148%) & [153%] of averages, largest since 2012 ranking 17 in Llansadwrn records since 1928. The mean temperature was 14.2C (+0.5) & (+0.4) of averages. The provisional 140.7h sunshine at RAF Valley was most since 2015, ranking 22 most sunny September on the Anglesey record since 1931.


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 August 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. 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]...

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