UK Weather - Summer 2024

[Simon Culling]

Summer has started with high pressure resident to our west (1036mb at 12Z today - 2nd June - well to the west of Eire - see chart below) and a slack N-NW flow that is warming as daily sunshine radiation is now above night-time radiational cooling. It has been nice and warm over much of central and western parts of the UK, but a breeze just off the North Sea is still keeping eastern parts cooler - this is normal in Spring and into early Summer. The temperature reached 23-24°C over much of England + Wales (away from the coast) today (Sun 2nd June) and here in Tiverton we had a sunny and warm day with a light wind and a high of 22°C - best day of the year so far as the humidity was quite low so it felt very comfortable.

However, the high will retreat a little further west this coming week allowing low pressures to move SE across Scandinavia and we will see a renewal of the NW flow with rain and/or showers and much cooler conditions. But here in the SW rainfall totals should be small.

The post contains public sector information licensed under the Open Government Licence v1.0

[Simon Culling]

Whilst it has remained mostly dry here in the south, there have been plenty of showers in the last few days in the northern half of the UK where it has been on the chilly side. As the high pressure retreated a little to the west (into mid-Atlantic), lows have been able to move SE from Iceland and we are stuck in a cool NW flow. Down here in the SW it has been dry with variable amounts of cloud and some sunshine at times - just a few fleeting very light showers today. The nights have been chilly with the temperature falling to 5°C on a couple of nights here in Tiverton town, but out in the country there has been a nip of ground frost in more sheltered locations. Not unusual for early June, but rather a contrast to the very warm start we have seen to the year so far.

A small waterspout was observed this morning off the west Wales coast (near to Borth) and it appears to have come ashore and inconvenienced some campers. Thankfully, only minor damage. Picture copied from this linked tweet.

https://x.com/CambrianNews/status/1799091801715847337

The CET for June was 12.9°C (-1.2°C) up to the 6th and the EWR was 3mm up to the 5th which is just 4% of the monthly average of 71mm.

[Simon Culling]

The rather chilly theme to the weather this June has continued as we still have winds from a northerly quarter. There has not been much in the way of rain with showers rather than continuous precipitation - and this looks like continuing through the coming weekend and into early next week. After that the models indicate a considerable warm up, but with the unsettled theme continuing with winds more from the S-SW.

This morning (Thursday 13th June) there was an air frost in places in Scotland and the low of -1.6°C at Kinbrace Hatchery in the far north (County of Sutherland) was a new date record minimum for the 13th - beating the old record of -1.4°C set at Dalwhinne (Highlands) in 1978. It is not often nowadays that we see any minimum records being set.

[Simon Culling]

The last few days have been showery, but the temperatures have begun to creep up - daytime maximums are now getting to around 20°C for England + Wales which is near to average. The showers have been heavy and thundery and there were 8 reported funnel clouds on Saturday (15th June) and a couple more yesterday (Tues 18th) - this is quite normal on showery days in late Spring and into the Summer, especially when local convergence zones become established. Picture below is from a video of a long funnel near to Burnley in Lancashire yesterday.

The forecasts for the next 10 days are rather promising with high pressure becoming dominant with plenty of dry and warm weather on the cards - not sure on the sunshine front as we can be plagued by cumulus development in the UK which spreads out in the afternoon to a Sc sheet to hide the sun.

The CET for June was 12.1°C (-2.0°C) up to the 14th and the EWR was 21mm also up to the 14th, which is 30% of the monthly average. The temperature average may return to a small surplus by the end of the month if the current long range forecast proves correct.

[Simon Culling]

The warmer (and drier) weather has duly arrived and the mercury hit 28°C yesterday (Monday 24th June) and as high as 30.0°C today at Chertsey Abbey Meads in Surrey. We will see a couple more very warm days in the southern half of the UK, but a weak cold front will see a virtually rainless transition to much cooler conditions by Friday. Not living up to the old adage that a British summer consists of "three fine days and a thunderstorm" which I believe was first articulated by King George II way back in the early part of the 18th Century.

Down in the SW we had a foggy start in Tiverton and a reasonable amount of sunshine today and a high of 25°C. That's hot enough for me!!

[Simon Culling]

The temperature hit 30.5°C at the Royal Horticultural Society site at Wisley just to the south of London (a Met Office site) yesterday (26th June) and that looks like the top number for this warm spell as much cooler air is now crossing the UK today (Thurs 27th June). We had a dampening of rain around dawn here in Tiverton, but sunny intervals have returned and it is 18°C as we approach noon. Much more comfortable.

The forecast for the next seven days is essentially dry for us in the south, but there will be some showers in the north, and we should see temperatures close to average, although we may have the odd chilly night.

The CET for June was 13.6°C (-0.5°) up to the 25th and the EWR was 31mm also up to the 25th, which is 44% of the monthly average.

[Simon Culling]

We are back into a W-NW flow in the UK now, but it does not feel as cold as it ought to - global warming, with the Arctic warming much faster than the temperate latitudes has taken the edge off the cold from air with a northerly source. It has remained mostly dry here in the south with sunshine at times and this sort of pattern looks set to continue for the coming week with only very weak fronts crossing the country. I prefer the cooler days a NW breeze brings - here in Tiverton we should see daily figures of around 20°C which is very usable.

The Glastonbury Music Festival is well underway and they have seen dry weather with some sunshine, so no mudfest this year. It is only about 40 miles to my NE, but no traffic problems for mid-Devon. Yesterday, a small dust devil was filmed at the festival and the attached picture is a screen grab from the video on this tweet:

https://x.com/simon_culling/status/1807043537415880851

[NZ Thunderstorm Soc]

Went to Glastonbury in 1992. There was mud around then but it was fine for the event. Had a good time. Met Van morrison and Richard Thompson who some of the leading acts there.

[Simon Culling]

Thanks, John - glad you enjoyed your visit to the Glastonbury Festival all those years ago.

The cooler weather has persisted here in the UK and it is gradually becoming more unsettled with showery rain at times. This looks to continue over the coming weekend and well into next week with no signs of any settled and/or warmer weather. Is 2024 going to be a 'poor' summer here in the UK?

There was a fresh dusting of snow yesterday (4th July - general election day) on the ski slopes at the Glencoe resort in the Scottish Highlands. The attached picture was taken at 3600ft, but this is not a rare occurrence on the tops of the Sottish mountains even in July - it does happen from time to time. Let's hope it is not a portent for the new Labour Government.

The CET for July was 14.0°C (-2.0°C) up to the 4th and the EWR was 6mm up to the 3rd which is 8% of the monthly average of 72mm. The current temperature value is equal to the final values for both May + June. What odds might you get at the bookies for this to be the case at the end of July?

[JP.]

Hi Simon, I understand the CET (central England temperature) but would that be classed the same as a NZ city's mean temperature or a different reading altogether?

Thanks for the updates

[Simon Culling]

Hello JP, the CET is a measure of the temperature in what is known as Central England - this is a triangular area bounded roughly by London to Bristol to central Lancashire. It was originated by Gordon Manley back in the 1950's and uses a small number of stations within the defined area. The map below gives an idea of the area concerned - which is within the triangle. The series extends back to 1659.

The CET series is only representative of that area, so should not be seen as a UK temperature. The Met Office produces monthly figures for all four countries of the Union as well as a UK average figure from its gridded observation network which comprises 400+ weather stations. There are often small differences between the UK and CET figures, but this is to be expected in an area the size of the UK and with our very variable weather - very much like NZ.

link to a brief description by the Met Office:

https://www.metoffice.gov.uk/research/c ... cet-series

[Bradley]

Looking at that data it looks like 1963 and in particular January 1963 is the gold standard for low temps since the late 1800's!

[Simon Culling]

Indeed it was, Bradley. I was only two at the time so do not remember the very cold winter of 1962/63 which lasted uninterrupted from just before Christmas through to early March. It had the fifth coldest January (average was -2.1°C) and the 7th coldest February (average was -0.7°C) in the whole CET series.

Back in the present, we have seen a return of the cool and unsettled weather with rain and/or showers at time. Being on the north side of the jet stream means it remains cooler than average - the highest temperature in the UK so far this month at the halfway stage of July has been just 24°C at Heathrow on the 11th and also at Tyndrum (West Scotland) yesterday. We have a lot of rain over the UK today (Monday 15th July) with plenty more to come this evening and overnight for the SE half of England with a few thunderstorms in the SE. When this rain moves away to the N/NE we will be in more of a S or SW flow and this will bring warmer air northward and we should see temperatures near to 27°C in the SE later this week. Not so warm for the rest of us as it will be quite cloudy still with a few showers. No sign of any prolonged warm weather in the computer models.

The CET for July was 14.4°C (-1.6°C) up to the 14th and the EWR was 60mm up to the 13th which is 83% of the monthly average.

[Simon Culling]

The warm-up this week was quite a bit stronger than first thought and shows how quickly heat can develop in the UK nowadays when the wind shifts to the south and we draw up the warmth from Europe. The mercury hit 28°C in the SE on Thursday and 30-32°C quite widely yesterday (Fri 19th July) with a high of 31.9°C at St James Park in the centre of London. This is the current highest value for this year and on the second anniversary of the UK breaching the 40°C mark in 2022. It has proved short lived as a cold front is slowly progressing across the UK today (Sat 20th July) with rain for much of the western half of the country. This includes us in Tiverton where yesterday's sunshine and a high of 27°C has been replaced by muggy and cloudy weather with outbreaks of rain at times and a high of only 19°C.

The coming week looks predominantly dry here in the south with some sunshine and average temperatures, although there are tentative signs of a warm-up at the end of the month and into early August. Maybe we will get one decent summer month?

[Simon Culling]

The weather has not been too bad over the last few days - the warmth has not completely gone as we have temperatures a small amount above average. Not a great deal of sunshine, but it has been predominantly dry although rain + drizzle has moved east across the UK today (Weds 24th July). After more rain tomorrow, we should see a build of pressure from the Azores and the weather should be mostly dry through and beyond the coming weekend with some sunshine at times - we mostly get a build up of cloud during the days, even in summer.

SST's in UK waters are around average at the moment - a contrast to much of the Northern Atlantic which is rather on the warm side. Map below is for today.

The CET for July was 15.8°C (-0.2°C) up to the 23rd and the EWR was 84mm up to the 22nd which is 117% of the monthly average.

[Richard]

How has the storm day numbers been Simon.

[Simon Culling]

Hello Richard. The current year has not been very active thunderstorm wise here in the UK with totals some way below average. There has also been a shortage of severe storms despite the very unsettled weather. Most storms have been of the 'a few flashes and bangs' variety with no prolonged storms anywhere in the UK. There used to be an old saying, attributed to King George I from the beginning of the nineteenth century, that the UK summer consists of "three fine days and a thunderstorm". This is interpreted to mean that when we get the hot weather coming up from the south, it does not last long and the breakdown comes with thunderstorms. That has not been the pattern for the last twenty years or so, and the widespread outbreaks of storms, sometimes with an MCS or two, now seems to be more common on the near continent. Brexit cannot get our thunderstorms back!!!!!

The attached graphic is for the number of thunderstorm days at the very old site at Oxford (Ratcliffe) University with yearly totals of thunder heard for the last 200 years or so - it goes up to 2020, I think. There has been a downward trend since the middle of the twentieth century, although this measure will always depend of the vigilance (and hearing) of the observer.

[Richard]

Interesting how the chart matches other charts that shows the 1930's a was period of higher US wild fires, number and severity of land fall hurricanes and extreme heat waves.

[Simon Culling]

I do not have the knowledge to comment on any links to the US events mentioned by Richard, but the decline in thunderstorms in the UK may well be linked to recent warming trends. The Arctic is warming faster than the temperate zones in the northern hemisphere and this is affecting the depth of the cold air we receive from the north, and this in turn seems to be pushing the instability associated with summer plume breakdowns further east in the summer months. This is addressed in this recent article from a meteorologist at NetWeather.

https://www.netweather.tv/weather-forec ... son-for-it

Ironically, the current developing hot spell may well end with a thundery breakdown later in the week! Today (Monday 29th July) the temperature reached 30°C in the London area and will probably hit 32°C tomorrow - could be hottest day of the year so far. The thundery breakdown looks like starting on Wednesday night and the forecast has a lively low pressure system approaching the NW of the UK by the weekend!

EDIT: Replaced cooling with warming in second line! Makes a small difference!!

[Simon Culling]

We have had a very warm week here in the UK with the temperature peaking on Tuesday (30th July) when 32.0°C was recorded at both Kew Gardens + Heathrow Airport in London - this is the highest temperature of the year so far for the UK. The thundery breakdown did arrive on Thursday but only affected central and eastern England rather than all of the UK. There were some very heavy downpours (up to about 50mm in a hour) with some local flooding, but no reports have been received of any large hail or strong winds. It has become a little fresher since then, but it still feels rather muggy even today (Sunday 4th August). The Met Office reported that there were 7000 lightning strikes over England (and a few in east Wales) on Thursday, but an MCS passed close to the SE of England overnight Wednesday into Thursday morning will a very good lightning display seen on the SE English Channel coast.

Attached map (from Blitzortung) shows the lightning strikes in the 24 hours to 21Z on 1st August. As you can see NE France and parts of neighbouring Belgium got absolutely blitzed.

[NZ Thunderstorm Soc]

I notice that there are alot of storms in a line moving east over North Ireland/Scotland at the moment, also England.

[Simon Culling]

Indeed, John. These thunderstorms developed in Eire yesterday afternoon (Sunday 11th August) and became more organised as a cold front moved eastwards. The storms crossed into Scotland and did not exit the east coast until lunchtime today (Monday 12th August). They are still going off the east coast of Shetland at 5pm Monday afternoon. There were also a few elevated storms over southern England and the Midlands and the chart below has the cumulative lightning flashes for the UK and near continent for the 24 hour period to 5pm on Monday. The bulk of the 20,000 strikes were over Ireland + Scotland.

We had a lovely little elevated storm here in Tiverton this morning with 6 rumbles and a brief heavy shower (with large droplets) just after 8am. It came from glaciated Altocumulus Castellanus with a base around 8-10,000ft and marked the arrival of cooler air for us in the west.

[Simon Culling]

It has been warm and much more summerlike in the last week or so here in the UK. The highest temperature of the year occurred on Monday 12th August when 34.8°C was recorded at Cambridge NIAB site - 16 Met Office sites recorded a rounded up 33°C or higher on this date.

It has cooled off since Monday, but we have seen plenty of sunshine and daily temperatures in the range 22-25°C over much of England + Wales. There has been some rain further north, but very little here in the south. We can enjoy a mostly dry and warm weekend, but something more unsettled looks on the cards for next week.

The CET for August was 18.2°C (+2.4°C) up to the 15th and the EWR was 17mm up to the 14th which is 21% of the monthly average.

Attached is the Met Office summary for July 2024 which was cooler and duller than average over the UK, with the UK rainfall figure spot on average. This hides the fact that is was wetter in the south and drier in the north than average.

https://blog.metoffice.gov.uk/2024/08/0 ... dull-july/

[Simon Culling]

The weather in the UK has cooled in the last few days and become more unsettled with rain and/or showers and this looks like continuing for the rest of this week and into the coming weekend. It will also be rather windy - unseasonably windy in the north - but this will please the green energy suppliers, but no necessarily the customers, as despite further investment in wind + solar, prices for both gas and electricity are set to rise again substantially this autumn and winter - just as we start using a lot more of it!

Much of the rain will fall in the NW of the UK and particularly Western Scotland, with a Met Office warning now in place for up to 150mm on the higher ground for Weds/Thurs. Nowhere near that much here in the south, but there is some uncertainty on how much rain we will get from the weather system arriving for Friday (23rd Aug) which contains the remnants of Hurricane Ernesto. These can be very difficult to forecast as the residue of warm and moist air from the tropical system is not always well handled by the models.

SST's around the UK continue to be about average, although the 20°C in the east of the Channel + southern North Sea is not bad. Map is for last Saturday.

[Simon Culling]

I mentioned a couple of days ago that the models struggle with ex-hurricanes when their remnants make it across the Atlantic to NW Europe. Today (22nd Aug), the Met Office named a developing low pressure area as Storm Lilian and it is expected to deepen quickly tonight and into tomorrow as it moves ENE across southern Ireland and then northern England before exiting into the North Sea by midday Friday at around 980mb. It is unusual to have a named storm in August here in the UK, and the latest forecasts suggest gusts up to around 80mph in the Irish Sea and across northern England on Friday morning. The chart below is from the earlier Met Office forecast made around midday on Thursday (22nd Aug), but latest forecasts cover the same area for the strongest of the winds.