UK Weather - Summer 2020

[Simon Culling]

The heat has continued in the last couple of days, but it has been mostly concentrated in the SE of England, with many parts of the country wondering what all the fuss is about. Temperatures have not quite rivalled those of Friday, but have been close. Weekend highs were:

Saturday - 34.5°C at Frittenden (Kent), Herstmonceux (E Sussex) + Wiggonholt (W Sussex)

Sunday - 34.0°C at Herstmonceux

The overnight low on Saturday morning was as high as 22°C in places in SE England whilst a slight ground frost was recorded in the far north of Scotland, which was in a different air mass.

Here in Tiverton, we had a lovely sunny day today (Sunday 9th Aug) after the early morning clearance of mist and low cloud, but we only reached a high of 24°C and this was tempered by a pleasant northerly breeze.

The heat will continue well into the coming week and is likely to spread a bit further west and north, and there will be an increasing risk of thunderstorms from tomorrow, Monday 10th August. A few elevated storms have developed in the English Channel this evening and tomorrow looks to be an active day with some homegrown storms from midday onwards especially in the Midlands.

[Simon Culling]

The heatwave in the UK has continued, although it is finally beginning to cool off. Highest temperatures for the last few days were:

Monday 10th August - 35.5°C at London Heathrow
Tuesday 11th August - 35.7°C at London Heathrow
Wednesday 12th August - 35.4°C at London Heathrow
Thursday 13th August - 29.8°C at Porthmadog (NW Wales)

Not all the returns from the climate sites have been received by the Met Office, so Heathrow's monopoly on the daily highs may go when all the data is in. It is probably not since the summer of 1976 that we have had such a sustained period of temperatures this high. Night time temperatures have been holding up above 20°C at quite a few sites and some have seen three or four such nights. Not easy to sleep when it is this hot.

A thundery breakdown commenced on Tuesday evening and there have been widespread thunderstorms over much of the UK with plenty of hail and flooding and this will continue for a few more days as it continues to cool down. This BBC page has a few lightning pictures from the last couple of days:

https://www.bbc.co.uk/news/uk-england-53764430

The last picture shows the Clifton Suspension Bridge in Bristol (one of the creations of Isambard Kingdom Brunel) and I passed this on Wednesday night when it was lit up by the lightning. It was a majestic site.

The CET for August was 19.5°C (+3.4°C) up to the 13th and the EWR was 13mm up to the 12th, which is 17% of the monthly average.

[Simon Culling]

The temperatures have continued to fall in the last few days, but it has remained warm and muggy. It has also been very wet in places, but as is usual in what are showery synoptics, some places have had huge totals and others not much at all. Heavy showers and plenty of thunderstorms have been the order of the day (and night) since last Wednesday with sunshine much more at a premium than during the very hot weather. Radar estimates for the UK suggest around 150mm fell in parts of East Anglia on Sunday, with most of it falling in the afternoon.

https://twitter.com/danholley_/status/1 ... 4411140096

Quite a few local PWS's have recorded 50mm+ in a single day, but as can often be the case, the official stations were not in the right place at the right time. Here in Tiverton we have missed most of the rain, apart from a downpour on Saturday afternoon. At least it is not as hot!

[Simon Culling]

I have been working away from home for a few days and only followed the weather via the TV - and it has certainly become much more unsettled and generally cooler over the last few days. A significant depression (named Ellen) tracked north just to the west of Eire on Weds/Thurs and it deepened to around 968mb which is very low for August. It gave a swath of very strong winds to the SE coast of the island with some coastal flooding, felled trees and damage to power lines.

Roche Point (near the city of Cork) recorded a new record 10-minute wind speed average for August for Eire of 60kts (111km/hr) at 22:00Z on Wednesday 19th August and the 2nd highest gust ever recorded in the month of 77kts (143km/hr).

https://www.met.ie/storm-ellen-brings-u ... -weather-2

The Kinsale Energy (Gas) Platform off the south eastern coast of Eire recorded a gust of 98kts (113mph or 181km/hr).

The low has dumbelled around itself and is still to the NW of the UK this morning (Saturday 22nd) and has given the UK a blustery few days with plenty of rain, showers, thunderstorms and a few FC's. The outlook remains very unsettled and cool for the time of year.

[Simon Culling]

The weather has quietened down since Storm Ellen but it has not been in any way settled - still plenty of showers and not a lot of sunshine on offer. Temperatures have been around average, but mostly due to mild nights rather than warm days.

Storm Francis has been named by both the Met Office + Met Eireann and is approaching the south west of the UK this evening (Mon 24th Aug) and is set to bring a very windy and wet spell of weather to all of the UK over the next few days. The low is forecast to be around 980mb when it crosses the UK and wind gusts could reach speeds of 70mph or so in the more exposed places, but with the trees in full leaf, we could see a few of them toppling almost anywhere. There will also be a lot of rain associated with this system, and over the next 2-3 days, this may be the bigger problem. Quite a change in the weather from the record heat of just 10 days ago.

The CET for August was 18.8°C (+2.9°C) up to the 23rd and the EWR was 68mm up to the 22nd which is 88% of the monthly average.

[Simon Culling]

'Storm Francis' gave most of the UK an unusually windy day for the time of the year, with a number of Met Office sites setting new record wind gusts for the month of August. It seemed to have bottomed out at around 978mb as it crossed the Irish Sea with the strongest winds on its southern flank as they turned more west of south in the afternoon + evening (of Tuesday 25th). The system was seen by the models some 5 days in advance and the forecasts for both wind and rain were very good, even at 3 days out. Highest gusts seen were:

81mph at Needles Old Battery (very exposed)
75mph at Lake Vyrnwy (Powys, Wales - on a hill above the village)
70mph at The Mumbles (exposed coastal)
71mph at Aberdaron (exposed coastal)
68mph at Pembrey Sands (exposed coastal)
63mph at RAF Wittering + Avonmouth
62mph at RAF Cranwell

Here in Tiverton we had a windy day overall, although we were outside the worst area of strong winds. That said, the local site in the town (which is quite well exposed) recorded a gust of 52mph in the late afternoon and that seems about right from my observations.

There was quite a bit of tree damage and probably more problems with flooding. These two BBC stories give a flavour as the clean up continues today (Weds 26th August):

https://www.bbc.co.uk/news/uk-wales-53889484

https://www.bbc.co.uk/news/uk-wales-53907943

[Simon Culling]

Whilst the wind has died down, it has remained cool and unsettled with plenty of showers across the UK - indeed, there were at least 3 waterspouts seen in the UK on Friday 28th August and another in Eire. There have been some big rainfall totals in the last week or so and the month on average will be seen as wet despite the hot and dry start.

The emphasis for the next few days will be for it to remain on the cool side but much drier. Today, Sunday 30th August, was just about dry over the UK and here in Tiverton we had a mostly sunny day with no more than a gentle northerly breeze - but it was cool with a maximum of just 17°C. Tonight will be chilly in more western parts and where the skies remain clear, a ground frost is possible.

Looking further forward, the general consensus is for a build of pressure as we progress into September (and Autumn), but it will not be totally dry next week, and the cooler air looks likely to return for next weekend. Beyond that there is a suggestion of something a bit warmer.

[Simon Culling]

The summer season ended on a cool note on Monday with a mostly dry day for the UK and temperatures in the 15-20°C range after a chilly start - there was a ground frost at the more prone sites. Here in Tiverton it was a very pleasant day with a sunny morning before cumulus development at lunchtime restricted the afternoon sunshine somewhat. We had a high of 19°C after a morning low of 7°C. Similar weather has persisted into early Autumn.

The final CET for August was 17.6°C (+1.8°C) which makes it the 10th joint warmest (with 1736 + 1899) in the series dating back to 1659. The final EWR was 124mm which is a whopping 161% of the monthly average. The first half of the month was hot and fairly dry, but the second half was definitely on the cool and wet side.

[Simon Culling]

The Met Office have produced a good summary of August and the summer as a whole. August had two contrasting halves - with a hot and generally dry first half followed by a much cooler + wetter second half.

https://blog.metoffice.gov.uk/2020/09/0 ... o-a-close/

Summer as a whole was a little warmer (and this biased to the SE) and wetter than average. All three of the summer months were wetter than average, but the excess only just made up for the deficit during the dry Spring. It was also a rather dull summer, but again this balances out the very sunny (record breaking) Spring.