- 5 hours ago
This is an in-depth Met Office UK Weather forecast for the next week and beyond.
The hot and dry weather in parts of the UK and Europe has led to wildfires which have in turn caused thunder clouds.
Bringing you this deep dive is Met Office meteorologist Alex Burkill, looking at the meteorology behind these rare clouds and whether any rain is on the way for southern UK.
The hot and dry weather in parts of the UK and Europe has led to wildfires which have in turn caused thunder clouds.
Bringing you this deep dive is Met Office meteorologist Alex Burkill, looking at the meteorology behind these rare clouds and whether any rain is on the way for southern UK.
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NewsTranscript
00:00The hot, dry weather we've had recently, not only in parts of the UK, but also across parts of Europe,
00:07have led to some significant wildfires.
00:09I'm going to be talking about these as well as a few other things in this week's Deep Dive.
00:14Thank you so much for joining me. I'm Alex Burkill, presenter and meteorologist here at the Met Office, and I'm
00:19coming to you as we do every Tuesday from our headquarters here in Exeter.
00:23Make sure you hit that like button. Do leave any questions, any comments.
00:27I will be looking at them and we'll be going through some in the Weather Studio Live this coming Friday
00:31when Annie and I will be back.
00:33And also make sure you're subscribed and then you'll never miss one of these great Deep Dives or any of
00:39our other interesting videos.
00:41So wildfires. Yes, parts of the UK have had wildfires in recent days, recent weeks.
00:47The dry weather, the hot weather means that the wildfire risk is elevated and particularly across England and Wales where
00:54it's remaining dry.
00:55I'll talk about that in a second. But particularly in those areas, the wildfire risk does remain elevated.
01:01But I wanted to look at what's going on in parts of Europe where the wildfires have been severe.
01:07We have satellite imagery from yesterday and you can see a lot of smoke because of the wildfires.
01:14A load of smoke over western parts of Spain, also an area of smoke over eastern parts of Spain due
01:20to the wildfires.
01:21The wildfires to the west of Madrid are the country's largest on record.
01:27And there's also an area of wildfires over near Bordeaux, which is around four times the size of Paris.
01:35Hundreds of thousands of people have been evacuated due to these wildfires.
01:40And with the continuation of the dry, hot weather, I'll be looking at how the temperatures are rising through the
01:47next day or so in this part of Europe in a second.
01:50But with the continuation of the dry weather, it's likely that these wildfires could get worse.
01:56Now, one thing that has been talked about in association with these wildfires, because it's not a particularly common occurrence,
02:03but with sometimes when you get wildfires, you can also get storm clouds developing, thunderstorms triggered by the heat from
02:13the wildfires.
02:14There's pyrocumulonimbus clouds, like I have here.
02:17This picture is actually from California a few years ago, not from parts of Europe.
02:21But nonetheless, it shows this storm cloud that can develop as a result of wildfires or volcanoes.
02:27And yes, pyrocumulus, then pyrocumulonimbus, also known as cumulonimbus flammagenetus.
02:33And how does this develop?
02:35Well, when you get large wildfires, you get intense heat, and that leads to the air rising, as we get
02:42often when just the air is heated by the sun, that leads to it rising.
02:46But in this case, it's not the atmosphere leading to the cloud forming.
02:50It's the large, intense heat from the fires, the wildfires.
02:54That then causes the air to rise up.
02:57And as it does so, the smoke plume, that rises as well.
03:00And in the same way that clouds form generally, the water vapour within the air rises up, and as it
03:07does so, it cools down.
03:09Once it cools down, it can then condense.
03:11But for us to get our clouds, we need the water vapour to have something to condense on, a condensation
03:18nuclei.
03:19With the smoke plume caused by the wildfires, there is plenty, or there are plenty of particles for the water
03:26vapour to condense on.
03:27And so that's when you get your clouds.
03:29Initially, your pyrocumulus clouds.
03:31But if there's enough instability in the atmosphere, if there's enough momentum, enough updraft, then you get very large cumulonimbus
03:39clouds.
03:40And when I say large, these can rise to around 10, 15 kilometers in height.
03:45They can blast through the tropopause and into the stratosphere, and then they can spread out, spreading the smoke particles.
03:51And if that happens, well, the smoke particles in association with them, well, they can linger for quite a while,
03:57several weeks, in fact.
03:58But that's not the greatest cause for concern when it comes to these pyrocumulonimbus clouds, because they can cause further
04:07issues with regards to wildfires.
04:09You can get these downdrafts, downbursts, and that can lead to a bit of damage, yes, perhaps, but also can
04:15help fan the wildfires, causing them to spread quicker and further than they otherwise would have done.
04:21Now, there may be some rain in association with them, but not a huge amount.
04:25It's often quite light, so not really enough to help alleviate the issues as a result of the wildfires.
04:32Especially with a bit of wind shear, often the rain is a bit further away than the initial wildfires that
04:38triggered the thunderstorms.
04:40And there's also the potential for some dry lightning to occur, several kilometres, perhaps, away from the original wildfires, and
04:48that can then lead to more wildfires being triggered.
04:53NASA has labelled these as the fire-breathing dragon of clouds, because they can cause more issues, more wildfires in
05:02areas which are already susceptible, that are already suffering as a result of wildfires.
05:07Now, these are fairly uncommon. They were thought to be more unusual before the days when we had satellite imagery,
05:15because they weren't observed as much.
05:17But now, with satellite imagery, we can track them and see that they're slightly more common than we used to
05:22think across parts of North America and Australia in particular.
05:25They're not that usual in parts of Europe. But yes, in France, over recent days, these have been observed, and
05:31they have made the wildfire issue worse.
05:35Now, the ongoing problems are likely to continue, because there is more dry weather to come in that area, and
05:42we're going to see temperatures rising as well.
05:44I'll come on to that in a second.
05:46But first of all, I just wanted to go back to the UK and look at how dry it's been
05:50recently, because the answer is very dry indeed.
05:54This table here shows the stations which have had a large number of consecutive days without any rain being recorded.
06:03This is data up to and including yesterday, so the 27th of July.
06:06And if we look in that far right column, you can see a number of these stations.
06:11They still haven't had any rain, so their number is still increasing.
06:16It's been dry there today. There's more dry weather to come. I'll show you that in a minute.
06:19But yes, so those stations, a number of them, are going to continue to see that number of consecutive dry
06:25days rising through the rest of this week.
06:28Felsham, it's worth highlighting, actually, we haven't had any data from that site since the 18th of July.
06:33So in reality, that station could have had more days without any rainfall.
06:38But a large number of places haven't had any rainfall for such a long period of time.
06:44Is there any rain to come? Well, yes and no. It really depends on where you are in the country.
06:51Across northern parts of the UK, it is quite wet. There's more rain at the moment and there's more rain
06:57to come this week.
06:58But further south, it's a very different story. Really, really dry here.
07:02Let's zoom in just a little bit so we can get a bit more detail.
07:05But if I run this through, you see burns of rain coming in across parts of Northern Ireland.
07:10Scotland could see maybe 30, 40 millimetres of rain in some places, building up through the rest of today into
07:15tomorrow, maybe a bit more in some places.
07:17But if I just pause it there, all the time towards the south, it's dry, it's hot.
07:22I'll go through temperatures in a moment. But it is dry and it's hot.
07:26And we're not really seeing the rain that other parts towards the north are seeing.
07:31Then there is a front coming through and it brings a few spots of rain, but not a huge amount
07:34to southern areas.
07:36It's in northern parts where we're continuing to see some wet weather and further south, it stays dry.
07:41Into the weekend, it's a similar story.
07:44More rain across northern parts of the UK could be a bit heavy at times, but in the south, staying
07:50dry.
07:51Now, there is a weather system here which is coming closer towards us.
07:54This time yesterday, that had a greater chance of pushing its way across the UK in time for Sunday.
07:59But now the latest model runs keep it pegged back further to the west.
08:03So it looks like those southern areas really are going to stay largely dry, barely any rain as we go
08:10through the rest of this week and at least into the weekend as well.
08:14Let's look at the rainfall totals that we could get across parts of the north of the UK, because, yes,
08:21some places will have a bit of rain.
08:24Let's just make that the right view.
08:25And if we go through, let's pick our six hourly rainfall totals and let's just run through the next couple
08:30of days.
08:30Because, yes, with those bands of rain that I highlighted, some heavier amounts of rain across parts of Northern Ireland
08:35and western parts of Scotland, just north of the Central Belt, looks like it will be a bit wet through
08:40the end of today and into Wednesday.
08:42And then there's more rain in association with those bands through Wednesday as well.
08:46A pulse of heavier rain arrives through Wednesday afternoon across Northern Ireland, and that feeds further north and eastwards across
08:53parts of Scotland as well.
08:54Well, through Thursday, some more wet weather, and it's particularly as we go through Thursday afternoon into the evening.
09:01So I think I'm going to lose it.
09:02I have to go to my other chart here.
09:04But, yes, as we go through Thursday afternoon and into the evening, that's when we have the potential for some
09:08heavier rain across particularly northern, perhaps northeastern parts of Scotland to develop.
09:14Oh, apologies, that was our three-hour rainfall, so that was a little bit misleading.
09:17Let's go through to our six-hour rainfall just so it's the same scale.
09:21And you can see some high rainfall totals, maybe 40, perhaps up to 50 millimetres, building up in just six
09:29to 12 hours across some parts of the northeast.
09:31So it could be quite wet.
09:33All the while, if you've been paying attention looking further south, barely a drop of rain arriving here.
09:38And that's the picture that we also take into the weekend, not a huge amount of rain to come away
09:45from the north of the UK where it will be relatively wet at times.
09:51In terms of how wet, well, I've already alluded to it with those rainfall totals, but I just wanted to
09:56highlight Thursday afternoon evening time because that's when we have the potential for some heavier rainfall across parts of eastern,
10:03northeastern Scotland in particular.
10:04This chart is showing the chance of greater than 10 millimetres in six hours, but I think it's a very
10:12high chance, really, in this neck of the woods.
10:14And the lightning risk is quite high as well.
10:17We can see that if we look at a tephagram for that area for this coming Thursday, you can see
10:22the atmosphere, well, it's unstable.
10:24The lean in the tephagram showing that we have this potential energy that can zoom up, can boom up through
10:30the atmosphere, leading to those thunderclouds.
10:32Not due to wildfires or anything, but just your unstable atmosphere, allowing for the severe convection for the thunderstorms to
10:41kick off.
10:42So across eastern, northeastern parts of Scotland through Thursday afternoon, yes, there's a significant thunder risk, and we could see
10:48some high rainfall totals building up.
10:51Otherwise, rainfall-wise, and Sunday.
10:55I highlighted this earlier when I was going through the pressure chart, but as I mentioned, yesterday's model runs hinted
11:02that we could see this weather system coming in from the southwest and pushing its way across the UK.
11:07But that now looks like it's, well, less likely, more likely to be delayed at least until early next week
11:13if it does come across.
11:15Here I have the Met Office model on the left-hand side, and it keeps it way to the west
11:19-southwest of us.
11:20This is for midnight on Sunday morning, Merrick.
11:23Meanwhile, the EC, European Centre for Medium-Range Weather Forecasting, and the American, the GFS model, they do bring it
11:29still a little bit further east, closer towards the UK.
11:32But they're all in fairly good agreement that the dry weather looks set to last across those southern parts, at
11:37least through the weekend.
11:38Because even though they're a bit further east, they still keep that rain to the west of us.
11:42So if you are hoping for some significant rain in those southern areas, if you're a gardener, a farmer, or
11:47whatnot, I'm afraid it's not good news for the time being.
11:53Then, as well as it being so very dry recently, a big talking point has been how warm it's been,
12:00how hot it's been.
12:01Temperatures are rising again.
12:03Now, let's look back at what we've had so far.
12:07And this chart, which is from a website, roostweather.com, worth checking out if you want to delve into some
12:13statistics and some figures and some observations that we've had across the UK.
12:18It's a really good website.
12:19And what this chart is showing is how widespread the coverage of places exceeding their heatwave threshold since the beginning
12:29of May.
12:30So this top chart looks at, day by day, whether or not each place has exceeded their threshold temperature.
12:36Remember, around the London area, the threshold is 28 Celsius.
12:40And towards the north and west, it's only 25.
12:43So depending on where you are, it varies that value.
12:45But this takes that into account.
12:46And you can see that heatwave that we had towards the end of May, where we had our highest ever
12:50May temperature.
12:51Then the exceptional heatwave during the end of June, where we had our highest ever June temperature.
12:57And then the very long heatwave that we've had through a large chunk of July.
13:03Now, this top table is looking for individual days.
13:06The middle table is, or middle chart, is showing the, how widespread the coverage of stations which had at least
13:14three days where they exceeded their heatwave threshold.
13:17Remember, for it technically to be a heatwave, our current Met Office definition is three consecutive days exceeding your heatwave
13:23threshold.
13:24So these are places where it has been exceeded.
13:26Now, technically, the May one only lasted around five days.
13:31The June one, similar, was five or six days just by the skin of its teeth.
13:36Interestingly, this July one has gone on for such a long period of time.
13:40But there's been peaks and troughs in terms of how widespread it's been and also exactly where it's been.
13:46So some places, the southeast, they were hot initially and then they dropped down a bit and then they've risen
13:52up again.
13:53And you can actually see that, to be honest, since I think it's around the, I can't remember what date,
14:00but it was a long time ago.
14:02It was early in July, somewhere in the, I think it's around the 3rd of July, I think I looked
14:07up, somewhere in the UK has been in its heatwave threshold.
14:12Both in terms of it's exceeded its value and it's been on at least three consecutive days exceeding that value.
14:20So it's gone on for a really long period of time.
14:22But in recent days, Sunday was a cooler day.
14:24There haven't been that many places.
14:27But now, as we go through the beginning of this week, we're seeing more places picking up again.
14:33And again, we're going to see the heat becoming more widespread.
14:36No, that's not true.
14:37We're going to see the heat peaking in the southeast on Wednesday.
14:42And that's when we like to see temperatures back into the mid-30s.
14:45I'll show you that again in a second.
14:47So this heatwave has gone on for a really long period of time.
14:51But because we had this chunk, if you will, where there was a larger, more areas were in their heatwave
14:57threshold than the very small number of stations over the back end of last week and a little bit before
15:03that.
15:04We're kind of classing this as heatwave one, this is heatwave two, this is heatwave three.
15:08And now we're in a heatwave four at the moment because we're going to see temperatures again, like I say,
15:14getting back into the mid-30s Celsius.
15:17Looking at individual stations and taking Exeter Airport, for example, and this is the site across the UK which had
15:25the longest run of its heatwave threshold being exceeded.
15:29It had 21 days in a row.
15:32Sunday was the first day where it didn't.
15:34But yeah, 21 days in a row where it exceeded its heatwave threshold.
15:39And quite interesting, if you go back to just the few days before, so I think that's the, I'm trying
15:45to picture it,
15:46I think that's the third and the fourth.
15:47They were 24.7, 24.8 Celsius, so very close to the 25 Celsius threshold that Exeter has.
15:55But then it jumped up and temperatures were in their very high 20s, low 30s.
16:00I mean, yeah, low to mid 30s really for a large chunk of July.
16:05And then they've gradually dropped down a little bit.
16:07And then, as I mentioned, Sunday was a slightly fresher day.
16:10But then we jumped back up and got above 25 on Monday.
16:14So, yeah, another day with temperatures above the heatwave threshold.
16:18But yes, 21 days in a row for Exeter Airport where it had its heatwave threshold exceeded.
16:24So, yeah, a very long, three-week-long heatwave.
16:27It has been, I've almost forgotten what it's like to see rain and what it's like to not be hot,
16:35to be honest.
16:37But what's going to happen going forward?
16:39And I can show you that in a few different ways.
16:42Here I have our 1,850 hectopascal thickness.
16:46So we're looking at the warmth in the air by looking at how thick it is.
16:49The thicker the air, the more warmth there is because it spreads out more.
16:53And what we can see through today, we have some relatively high thickness, in excess of 140 over parts of
16:59East Anglia, Lincolnshire,
17:01and down into more, towards more central parts of southern England.
17:06But we have, we're dragging in some hotter air from the south through the end of today and into Wednesday.
17:13And that means we're getting even higher thicknesses, in excess of 142 across parts of the east-southeast of the
17:21UK on Wednesday.
17:22So that's when we're likely to see the peak of the heat.
17:24Worth noting, further north and west, there's a change.
17:27We're seeing fresher air coming in from the northwest by Wednesday.
17:30So more places will be slightly cooler on Wednesday than today.
17:34But in the southeast, it's going to be markedly hotter.
17:37And then the highest thicknesses, they clear away towards the southeast.
17:42So there is a bit of a change and things will turn a bit fresher, a bit more comfortable later
17:46on in the week.
17:47Let's show you that now, if I put on our air mass chart.
17:51And if I just run this through, and you can see the fronts that are bringing rain across parts of
17:56Scotland, Northern Ireland, Northern England at the moment.
17:58But we're ahead of this.
17:59Actually, one thing I wanted to show at the same time as I do this is the wind direction.
18:03You can see into Wednesday, we're getting our winds coming up from the south.
18:07There's a lot of hot air across parts of France, Spain at the moment with those wildfires as well.
18:14And we're tapping into some of that, which is why we're seeing those higher thicknesses in our air across parts
18:19of the southeast on Wednesday.
18:21Because of the slight shift in the wind direction as this high pressure to the east of us shifts away
18:26towards the east.
18:28But running through, yes, we have hot air across parts of the southeast.
18:32There is a front coming through on Wednesday.
18:34As I mentioned earlier, it doesn't bring a huge amount of rain, but it does bring slightly fresher, slightly more
18:39comfortable perhaps in from the northwest.
18:42And so temperatures by the end of the week will be a fair bit lower than they are on particularly
18:47on Wednesday.
18:48Even today, I mean, temperatures are in excess of 30 Celsius today.
18:53And, you know, it's not it's been a few days since we've been above 30 Celsius, not super long.
18:58But it's hot. And then, yes, it's going to be even hotter still on on Wednesday.
19:06Then I did just want to whilst we're looking at this chart because I wanted to show it the temperatures
19:12across parts of Europe.
19:15And if I just remember how to do this or put a temperature already there, let's put a couple of
19:20temperatures just randomly on because, yes, temperatures across parts of Europe at the moment are exceptionally.
19:25Oh, I can't do that with that on are exceptionally high.
19:28And we're seeing if I just run this through through Wednesday, you know, high 30s, getting into the low 40s
19:37across parts of Spain.
19:38If I put a couple of temperatures there and also in France, we could be looking at temperatures getting into
19:43the low 40s as well, peaking on Wednesday.
19:45And then whilst the hot air continues across parts of Spain into Thursday, you know, temperatures could be looking at
19:5240 to 45 Celsius in some places here across France.
19:56We're actually going to see the extreme heat clearing away towards the east and pushing across more parts of Germany.
20:02And that's where we're going to be seeing temperatures into the mid to high 30s, perhaps.
20:07So France's hottest day is likely to be tomorrow when there's a reasonable chance some places will get above 40
20:14Celsius.
20:14Meanwhile, for Spain and then later, more eastern parts of Europe, it continues or pushes its way in slightly later
20:23in the week.
20:24And with the hot weather, well, as I mentioned, that's going to keep those wildfires a major cause for concern.
20:31One other thing that I can show you if I get this chart up and let's get rid of those.
20:38Cool. And I wanted to just highlight our maximum temperatures for the next few days.
20:44Let's start off by looking at today. I already mentioned it, but 30 Celsius quite like, well, we've seen 30
20:50Celsius today in the southeast, I believe.
20:52And it's the first time, as I mentioned, for a little while that we've been above 30 Celsius, but not
20:57super long.
20:57And then tomorrow we're likely to see temperatures peaking around 34 or 35.
21:02If we get above 35, it will be the seventh day this year where somewhere in the UK has had
21:09temperatures in excess of 35, so equal to or in excess of 35 Celsius.
21:14That's a record. We'd already beaten the record for the most number of days above 35 Celsius in a year.
21:19And so if we get above it again, that record is just going to get pushed even further.
21:23But as I mentioned, well, two things, fresher air starting to push its way in across northern and western parts
21:29by Wednesday.
21:30So whilst it's hotter in the southeast, it's fresher towards the northwest.
21:33Meanwhile, that fresher air will eventually make its way further south and east through the end of the week.
21:39But we're still looking at temperatures in the mid to high 20s, so it's not exactly cold by any means.
21:45And even as we go further ahead through the weekend and into next week, we're still looking at mid to
21:50high 20s and lots of dry weather, as I alluded to,
21:53lots of sunshine, especially towards the south through the weekend and even into the beginning of next week.
21:59So really, if you're after something cooler, it's, you know, tomorrow is going to be the hottest day for a
22:04little while,
22:05but it's not going to be a much cooler temperature still above average for many, especially across central and southern
22:11parts.
22:12And if you're after something drier, sorry, no, not many people are after something dry.
22:17If you're after something wetter, well, really, in the south, you do have to wait for quite a while longer.
22:26Right, I think that's everything that I wanted to cover today.
22:29Thank you for joining me for this week's deep dive.
22:31As I said at the start, hit that like button, get your comments, your questions coming in.
22:35We'll be looking at some of them this afternoon and also some of them in the Weather Studio Live on
22:40Friday with Annie and me.
22:42And make sure you're subscribed and make sure you're sharing this with anyone who you think might be interested in
22:47anything that I've talked about today.
22:49Then one last thing that I did just want to point out.
22:52On the 12th of August, so it's a little while away, but I wanted to give you an early heads
22:56up.
22:56There is an Eclipse, which will be visible across parts of the UK.
23:01And so you may want to think ahead.
23:03And if you're planning on viewing it, you may want to get yourself some Eclipse sunglasses.
23:07Got a little tip this morning that they're relatively cheap at the moment, but the price for them will go
23:12up as we get nearer the time.
23:14So you may want to plan ahead.
23:16Anyway, thank you so much.
23:18And I will see you again soon.
23:20Enjoy the rest of your day.
23:21Bye bye.
23:21Bye bye.
23:21Bye bye.
23:21Bye bye.
23:22Bye bye.
23:22Bye bye.
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