UK Weather - Summer 2020

[Simon Culling]

Summer began with two more sunny and warm days over much of the UK with a high of 28°C on Monday and 27°C on the south coast yesterday (Tues 2nd June) at Gosport. However, a rather complex set of fronts has moved south over the UK today (Weds 3rd June) and given us a very different day - plenty of cloud and outbreaks of rain, although nothing significant, and much lower temperatures. This will be the theme going forward for at least the next week, so just as the lockdown begins to end so does the good weather.

Quite a deep low looks set to develop Fri/Sat in the North Sea with a central pressure down to around 978mb and depending on how far west it comes, we could see some very windy, wet and cold weather over much of the UK over the weekend which is quite a change from the last couple of months. The detail is not set in stone yet, but the eastern side of the UK will likely see the worst of the weather. After such a long dry spell, at least there will be some rain for most of us.

[Simon Culling]

It has turned much colder in the last few days as the low in the North Sea has delivered winds from a northerly quadrant. Yesterday (Sat 6th June) in Tiverton was cold and cheerless with constant drizzly rain accompanied by a keen NW breeze and a maximum of just 11°C. Further east, quite a few thunderstorms formed on a couple of troughs moving south east and my old stamping ground of Milton Keynes had a couple of storms in the afternoon with a carpet of hail from the first one. The video on the link below shows the convection building from lunchtime over eastern England and the London area all in the circulation of the low just on the east coast.

https://twitter.com/liamdutton/status/1 ... 0996107266

Looking ahead, the models are struggling with a trough disruption next week, but it looks to remain on the cool side with the potential for quite a bit of rain for more southern parts of the UK where the rain is most needed.

[Simon Culling]

The weather has turned much wetter in the UK with plenty of rain and showers, although some areas have had a lot more rain than others. A low pressure system has become established in the Bay of Biscay and will sit there for a few days and push rain northwards to the UK - as well as much warmer and more humid air, so thunderstorms may well feature over the coming weekend.

It was wet here in Tiverton over Weds/Thurs with local sites recording between 30-40mm of rain and we had some hail mixed in the showers yesterday, although the thunderstorms missed this part of Devon. Brighter today (Friday) but further rain is pushing up from the south for later today and overnight. It also feels much more humid today. Further to my west, some sites have seen 60-70mm of rain, so the 'drought' is well and truly over for this part of the UK.

The CET for June was 13.2°C (-0.4°C) up to the 11th and the EWR was 29mm up to the 10th, which is 44% of the monthly average of 65mm.

[Simon Culling]

The unsettled and warm theme has continued over the weekend with plenty of showers and thunderstorms across the UK, although not everywhere has seen the rain - such is the case with showers! We have missed the thunder here in Tiverton, but Saturday was a wet one with frequent and heavy showers. We managed a dry day on Sunday with plenty of warm sunshine, but the five calendar days up to then have produced 63mm at a close by PWS to me and that seems about right for the town - it has certainly been a volte face from the couple of months of dry weather previously. It has also been quite warm in more south eastern parts of the UK with 25°C reached on both days of the weekend.

Looking ahead, the warm theme will continue and with a flabby area of low pressure persisting to the south of the UK, it will remain showery for the next few days with an on-going risk of home grown thunderstorms almost anywhere. We should see something a bit drier by the end of the week.

The CET for June was 14.0°C (+0.2°C) up to the 14th and the EWR was 41mm up to the 13th, which is 63% of the monthly average.

[Simon Culling]

The very showery theme has continued, with widespread thunderstorms on Sun/Mon and at least 12 funnel clouds reported on these two days. Most of the storms have occurred on local convergence lines with Wales and NW England catching the worst of the storms. Up to 50mm has fallen in places in a short period of times (1-2 hours), so there has been some local flooding, but many observers have commented on the frequency of the lightning and the strength of the thunder.

Here in Tiverton we have missed most of the action with a dry day on Sunday and only a few rumbles in the distance yesterday - a large are of storms developed to the north of me on a convergence zone over the Exmoor hills and got rather stuck - the EA gauge at Haddon Hill recorded 48mm of rain in the afternoon.

Further showers have broken out today to my west and north (and over other parts of the UK) as we approach noon on Tuesday and if we can clear the low stratus clag we have at the moment and get a bit of sunshine, we could see a lively storm or two in my area this afternoon.

[Simon Culling]

The unsettled and thundery weather continued through the rest of last week and into the weekend here in the UK, although the last of the thunder was on Friday - it has been replaced by frontal rain and then showers today, Sunday 21st June. Some places in NW England had 5 consecutive days with thunder last week and the storms were particularly strong in this region - the link below gives a map derived from lightning reports to show the distribution of the thunder which does not quite follow what might be described as normal - the SE is usually the most thundery area of the UK.

A change in the weather is now underway as the stubborn low to our south has moved away to be (briefly) replaced by a low off the Atlantic. As this low moves away to the NE and a ridge of high pressure builds from the SW, we will see increasingly warm air be advected north over the UK from southern Europe with some rather hot weather to come from mid-week onwards. We will see the first 30°C+ temperature of the year by Wednesday.

https://twitter.com/convectivewx/status ... 5150326787

[Simon Culling]

The weather is warming up in the UK and today (Tuesday 23rd June) saw the highest temperature of the year (so far) recorded - 28.6°C at both Kew Gardens and London Heathrow. That figure will be eclipsed tomorrow and possibly again on Thursday, with the Met Office predicting a high of 33°C on both these days in and around London. Tomorrow will be sunny, but some showers or thunderstorms are possible on both Thurs + Fri, so this may have an effect on the temperature if a large residue of cloud results from the showers.

Here in Tiverton, today was a sunny day with just a few bits of cumulus and cirrus after mist and low stratus cleared away soon after 7am. We reached a high of 25°C and it is still very warm late into the evening - I have all the windows open to try and cool the house down as all the sunshine that was soaked up by the bricks during the day is now being re-radiated.

The CET for June was 14.6°C (+0.6°C) up to the 22nd and the EWR was 80mm up to the 21st, which is 123% of the monthly average. This will be yet another warmer than average month.

[Simon Culling]

The mercury reached 32.6°C yesterday (Weds 24th June) at London Heathrow and 30°C was reached or exceeded across much of the southern half of England and into parts of Wales as we 'enjoyed' yet another day of wall to wall sunshine. Here in Tiverton it was sunny all day with just a gentle SE breeze and a maximum of 30°C. Thursday has been a repeat so far, but a few thunderstorms have developed in the far west and more surprisingly, the NW of Scotland this morning, and this is a sign of a change in the weather in the next 36 hours to a much cooler Atlantic regime. Could be some strong thunderstorms later today and into Friday as we make that transition.

The UV level over the UK is very high at the moment and we may see a record level of 9 in some parts today. The coronavirus has meant reduced levels of pollution, little or no air travel (less contrails) and this combined with the solar maximum as we are right on the summer solstice and a notable reduction in the Ozone level over NW Europe and we have the perfect recipe for very strong sunshine in the UK.

Link below to a rather waffly article from the BBC on UV and the UK:

https://www.bbc.co.uk/news/explainers-53178988

[Simon Culling]

The UV story on the BBC was a bit misleading and a 'record' UV level was not set during the recent hot spell. The synoptics were not right - and I should have known this. We had a relatively moist SE flow over the UK with plenty of attendant pollution from our European friends and this would restrict the UV levels enough despite the lack of homegrown pollutants and the proximity to the solstice. To get record levels, a more westerly or north westerly flow (off the Atlantic) would provide much clearer air. The reality is that the sun is powerful around the June solstice even in the UK and we should all be mindful of that when outside - it is not just a matter of how hot it is.

Thursday (25th June) was a little warmer with a maximum of 33.4°C at London Heathrow and a third day of 30°C+ temperatures was recorded on the Friday - before much cooler air arrived from the west. This cooler air helped some decent storms develop on Friday with the north of the UK particularly affected - some knobbly hailstones up to about 50mm in size fell in Sheffield and the western isle of Lewis also saw some very heavy rain and unusually large hailstones (on Thursday) for this part of the UK. See the linked tweet.

https://twitter.com/IslesWeather/status ... 2751677441

It is much cooler now as we start the new week and here in Tiverton it is cool and windy with a few showers on Monday (29th June) and the temperature is struggling at just 17°C. The rest of the coming week looks very cool and showery.

[Simon Culling]

The weather has been much cooler and more unsettled since the hot spell ended last weekend and the seven day forecast has much the same in store, although it should be drier and a little warmer for more southern parts of the UK. Quite a vigorous system will cross the UK tomorrow (Sunday 5th July) with some strong winds for the time of the year - up to 60mph has been predicted for the Pennines and N York Moors.

It has been rather wet over the high ground in Wales, NW England and western Scotland in the last couple of days and particularly so in NW Wales. Over 100mm had fallen at a number of the hill rainfall sites in the last 36 hours and there has been some flooding. Just to the east of the mountains, only a few millimetres has been recorded. Those of you in the South Island will be familiar with this effect.

June was warmer and wetter than normal and especially wet in SW England. The Met Office have produced a good summary and posted it on their blog:

https://blog.metoffice.gov.uk/2020/07/0 ... tatistics/

The final CET for June was 15.3°C (+1.2°C) and the final EWR was 97mm, which is 149% of the monthly average.

[Simon Culling]

The rather cool and unsettled weather has continued in the UK for the last few days, although rainfall totals have not generally been large. Here in Tiverton it has been predominantly cloudy with plenty of drizzle and mist and the temperature has been no higher than 19°C. That said, it has felt rather muggy and the house temperature is still 21°C.

There was a brief incursion of quite chilly air (for the time of year) into the far north of the UK on Tues/Weds this week and a couple of sites in the northern Highlands reported an air frost. Kinbrace recorded -0.6°C and Altnaharra -0.5°C. Both of these sites are not far from sea-level. The record low for July for the UK is -2.5°C which was recorded at Lagganlia (in Inverness-shire) on 15th July 1977.

Looking ahead, high pressure is set to build across more southern parts of the UK from the SW so we will see a change in the weather by the weekend to dry and settled conditions - and a little warmer.

The CET for July was 15.3°C (-0.4°C) up to the 8th and the EWR was 21mm up to the 7th, which is 34% of the monthly average of 62mm.

[Simon Culling]

It has warmed up a bit in the last couple of days with plenty of sunshine to cheer us up in these trying times. The mercury hit 25°C in the London area on Sunday and has done so again today. We do have some patchy rain moving across from the west today (it is currently raining here in Tiverton at 3pm on Monday afternoon), but it looks like a temporary blip in the settled conditions, and after a couple of cooler days with the odd shower, it will warm up again from mid-week with increasing sunshine, particularly to England + Wales. We could see a temperature of near 30°C again in the SE over next weekend.

Sunday morning was another cool one, especially over Wales and the SW of England with a local ground frost. The lowest air temperatures were 0.3°C at St Harmon and 1.3°C at Sennybridge - both in Powys in central Wales. That is not far short of the July record for Wales which is -1.5°C at the old site at St Harmon (it moved in 2018) which was recorded on 3/7/1984.

[Simon Culling]

The weather has warmed up gradually in the last few days and particularly for more southern parts. Yesterday, Friday 17th, the temperature hit 28.5°C at London Heathrow Airport and we could see similar temperatures again today. After that it looks to cool down, although any worthwhile rain is likely to be further north. The Test Match at Old Trafford (Manchester) will probably be a washout today (Saturday) as the front dividing the warm and cool air gets stuck over north Wales and northern England. This front will weaken as it heads south tonight and tomorrow, but will introduce cooler weather to the south by early next week. The rest of the month weatherwise looks much of a muchness.

The CET for July was 15.4°C (-0.5°C) up to the 17th and the EWR was 39mm up to the 16th, which is 63% of the monthly average. This could be the first colder than average month this year, and indeed, since Oct + Nov 2019.

[Simon Culling]

This is the time of the year here in the UK that we can witness large clouds of flying ants - and as was the case last year, the Met Office radar seems to be able to pick up some of the swarms. As they occur when it is dry and sunny, there will be no rain on the radar image to get in the way.

The Met Office posted a tweet on this subject on Friday 17th July - which may prove to have been the warmest day in July with a maximum of 28.5°C at London Heathrow (as reported above):

https://twitter.com/metoffice/status/12 ... 3331038208

[Simon Culling]

Apart from the flying ants, not much is happening on the weather front here in the UK. It has been mostly dry and bright with temperatures around normal, but we have moved into a slightly more mobile pattern in the last day or so - we have even had a few millimetres of rain here in Tiverton. The forecast has a showery day on Saturday with a few thunderstorms in more eastern parts, and then back to the rather nondescript stuff. Interestingly, the longer range output is indicating a short plume event for the first weekend of August, but this is 8 days away at the moment.

The CET for July was 15.4°C (-0.5°C) up to the 23rd and the EWR was 46mm up to the 22nd which is 74% of the monthly average. Still on target for the first colder than average month in 2020.

[Simon Culling]

We had two tremendous downpours here in Tiverton yesterday, Saturday 25th July, with over 25mm of rain from the two showers/thunderstorms that lasted about one and a half hours in total. Most of the rain fell in two burst of torrential rain + hail totalling about 15 minutes around noon and half past four in the afternoon. Best storms since I moved to Tiverton about a year ago - the second one produced about 30 peels of thunder with a few c-g strikes as well and some local flooding.

Later in the day, a tornado was filmed by many people in Northampton and was particularly photogenic as far as UK ones go. A couple of Twitter videos attached - you can see debris being scattered on the second video.

https://twitter.com/HeartNewsEast/statu ... 7860023296

https://twitter.com/Wx_NickJ/status/1287115225511145473

[Awhituobs]

https://abcn.ws/300TEqd

[Simon Culling]

Thanks for the video link, Brian. It was certainly one of the most filmed and photographed tornadoes in the UK for some time.

The weather has trundled along since the excitement of the weekend with a cool NW flow and some showers and sunny spells for the last couple of days. Thankfully the weather did not interfere for long enough to prevent the third and final test match against the West Indies from being completed on Tuesday. However, the wind has changed to a southerly today and we are drawing in much warmer air from a very warm continent. That said, this will be a very brief 'heatwave' for the UK as cooler air is expected to spread back in from the Atlantic over the weekend. Friday will be a sharp peak in the heat with possibly 33/34°C for the London area and up to 30°C even in northern England.

The CET for July was 15.7°C (-0.3°C) up to the 28th and the EWR was 67mm, also up to the 28th, which is 108% of the monthly average. The late surge of heat looks like it will probably prevent July from being a colder than average month after all.

[tornado]

https://abcn.ws/300TEqd

i see comments on youtube of people calling it a mini tornado lol.

[NZstorm]

I see Heathrow Airport 37C today.

[Simon Culling]

Indeed, NZstorm, it was a very warm day in much of England - in fact it was the third warmest day on record. The highest temperatures were recorded in and around London, but 35°C was reached as far north as Lincolnshire + Birmingham:

37.8°C at London Heathrow (exactly 100°F in old money)
37.3°C at Kew Gardens
36.8°C at RAF Northolt
36.7°C at St James Park + Teddington Bushy Park
36.6°C at Chertsey Abbey Mead + RAF Benson (Oxfordshire)

Here in Tiverton, in the west, it was hot and sunny by midday (up to 28°C), but cloud from a weak front then arrived with a few light showers and the temperature fell away.

[NZstorm]

The observed 850mb temperature at 12Z on Friday was 21C at Herstmonceux, East Sussex. Wouldn't see that too often over the UK. There was a lot of moisture in the mid levels which is why the storms developed over the Midlands.

[Simon Culling]

That is a high 850mb temperature, NZstorm. The total thickness level at Herstmonceux at the same time was 575.5mb.

The heat disappeared as quickly as it arrived over the weekend from most areas (although 28°C was reached in London on Saturday) and it has been much cooler since, although mostly dry here in the south. With the flow generally from the NW it has been showery over most of the UK with at least 5 funnel clouds seen on Sunday + Monday in more northern parts.

We will see another change in the weather this week, with a further plume of warm air coming up from the south as low pressure systems run past NW Scotland. Yet again it will be more southern and eastern parts of the UK that see the hottest weather and the Met Office are going for 37°C again in the SE on Friday. This time it looks like the hot weather (although not quite as hot as this coming Friday) will continue through the weekend and into next week

The final CET for July was 15.7°C (-0.3°C) making it the first colder than average month this year and indeed since Nov 2019. The final EWR was 69mm which is 111% of the monthly average.

[Simon Culling]

The Met Office has published a summary of July's weather and it shows that it was cooler, duller and wetter than average over the UK, but with the usual regional variations. The SE was the driest and warmest part of the UK.

https://blog.metoffice.gov.uk/2020/08/0 ... able-heat/

The weather has warmed up in the UK over the last couple of days and 30°C was reached in London on Thursday afternoon. Tomorrow is expected to be hot over the SE half of the UK and the Met Office is now going for 36°C in and around London. The heat is set to remain well into next week and the threat of a few thunderstorms increases as well with time.

[Simon Culling]

The Met Office were spot on with their prediction for today with a number of stations in London recording 36°C as a maximum, but this was a repeat of the very hot day in July where the SE of England was by far the hottest place. Highest numbers were (for Fri 7th Aug):

36.4°C at Kew Gardens + London Heathrow
36.2°C at Chertsey Abbey Mead
36.1°C at RAF Northolt, St James Park + RHS Wisley
35.9°C at Cippenham STW
35.8°C at Teddington Bushy Park

35°C was reported widely in the Home Counties and up into parts of East Anglia.

Here in Tiverton, it was sunny in the morning, but persistent bands of Ac Cast through the afternoon and a few light showers capped the temperatures to 28°C. We even managed a one clap thunderstorm mid-afternoon from a very elevated Cb - I estimate about 8000ft for the base.

The London area has another five days of 30°C+ days to look forward to with an increasing risk of thunderstorms. Could be some interesting weather in the next few days.

The CET for August was 16.7°C (+0.7°C) up to the 6th and the EWR was 5mm also up to the 6th, which is 7% of the monthly average of 77mm. The CET was negative for the first 5 days!