- 15/08/2023
This is an in-depth Met Office UK Weather forecast for the next week and beyond.
Three fine days and a thunderstorm. That’s how George II described the British weather. And that’s how things are looking this week. It’s certainly an improvement on July when we didn’t even get three find days… bringing you this deep dive is Met Office meteorologist Aidan McGivern.
You may also enjoy:
– 10 Day trend forecast https://www.youtube.com/playlist?list=PLGVVqeJodR_ZDSHKqsgszMnk9d5IEF5UH
– Podcasts exploring weather and climate https://www.youtube.com/playlist?list=PLGVVqeJodR_brL5mcfsqI4cu42ueHttv0
– Daily weather forecasts https://www.youtube.com/playlist?list=PLGVVqeJodR_Zew9xGAqYVtGjYHau-E2yL
Subscribe to make sure you never miss the latest UK weather forecast or important weather warning - https://www.youtube.com/c/metoffice?sub_confirmation=1
We are the Met Office, the UK’s national weather service, and every day of the week we bring you a morning weather forecast and an afternoon weather forecast so that wherever you are in the UK we have you covered.
Forecast and any weather warnings are accurate at time of recording. To ensure you have the most up to date weather information, check the hourly forecast and live warnings on the Met Office website or app.
Three fine days and a thunderstorm. That’s how George II described the British weather. And that’s how things are looking this week. It’s certainly an improvement on July when we didn’t even get three find days… bringing you this deep dive is Met Office meteorologist Aidan McGivern.
You may also enjoy:
– 10 Day trend forecast https://www.youtube.com/playlist?list=PLGVVqeJodR_ZDSHKqsgszMnk9d5IEF5UH
– Podcasts exploring weather and climate https://www.youtube.com/playlist?list=PLGVVqeJodR_brL5mcfsqI4cu42ueHttv0
– Daily weather forecasts https://www.youtube.com/playlist?list=PLGVVqeJodR_Zew9xGAqYVtGjYHau-E2yL
Subscribe to make sure you never miss the latest UK weather forecast or important weather warning - https://www.youtube.com/c/metoffice?sub_confirmation=1
We are the Met Office, the UK’s national weather service, and every day of the week we bring you a morning weather forecast and an afternoon weather forecast so that wherever you are in the UK we have you covered.
Forecast and any weather warnings are accurate at time of recording. To ensure you have the most up to date weather information, check the hourly forecast and live warnings on the Met Office website or app.
Category
🗞
NewsTranscript
00:00 Three fine days and a thunderstorm. That's how George II apparently described the British summer.
00:05 And that's what we're seeing this week. A few fine days, temperatures rising, a brief warm spell,
00:11 and then the thundery breakdown later Friday and into the start of the weekend
00:16 before the weather patterns reorientate themselves once again to bring a return to showery conditions.
00:21 But there is the potential for another hot spell at the start of next week in some places.
00:29 However, there is a lot of uncertainty about that aspect of the forecast.
00:32 And I'll delve into the nitty gritty during this week's deep dive.
00:36 Welcome along. It's Tuesday. It's just after 1 o'clock at the time of recording.
00:42 I've had my lunch. I've had my haircut. We're ready to go in depth about the current weather situation across the UK.
00:48 And I'm going to look at this weekend mainly and the start of next week.
00:53 And I'll give a hint as to what we can expect a bit further ahead into the start of September.
00:58 But the weather patterns have certainly changed compared to how we were a week or so ago
01:04 and how we were stuck in the same pattern for a long time.
01:08 Now, throughout July and the start of August, we had a certain weather pattern that involved the jet stream diving to the south of the UK
01:16 and bringing low pressure after low pressure after low pressure.
01:20 We had in some places, Northern Ireland, Manchester, for example, the wettest July on record,
01:25 slightly below average temperatures for the month, a stark contrast to June, which was, of course, the warmest June on record.
01:32 Now we're into the final act of summer and the weather patterns have shifted once again.
01:37 Now, we're not seeing a return to June's constant dry and warm weather.
01:43 And we're not seeing a return to July's constant low pressure, unsettled wet weather.
01:49 What we're seeing now over the next few weeks, I think, is something a bit more changeable.
01:55 What I'd like to describe as fairly typical August weather.
01:58 So neither a prolonged hot and dry spell nor necessarily prolonged rain like we saw throughout much of July.
02:05 Something a bit more typical for the UK summer.
02:08 Sunshine, showers, some warmth and some cooler weather at times as well.
02:13 And that's summed up by the current situation.
02:17 We're still at the jet stream to the south of the UK at the time of recording.
02:20 That jet stream is less powerful compared with what we've seen recently.
02:24 It's still brought an area of low pressure our way.
02:27 We started Monday with some very wet weather in places, particularly Wales and Northern England.
02:32 That low is now moving away. And now if we just fast forward it 12 hours or so.
02:37 And you can see high pressure now moving in.
02:40 And this is what I mean. We've got now a situation where neither one nor the other is dominating.
02:46 You can expect a bit of high pressure, a bit of low pressure over the next few days and potentially the next couple of weeks or so.
02:53 With neither one dominating, fairly typical summer weather for the UK.
02:58 Might be good news for many of you.
03:00 But this is how things are looking on Wednesday.
03:02 This ridge of high pressure building across the UK.
03:05 Hence the three fine days followed by the thundery breakdown.
03:09 And the high pressure won't entirely diminish the shower risk.
03:14 There will still be some showers on Wednesday and into Thursday.
03:18 We've still got some instability in the atmosphere, but mostly showers will be very well scattered.
03:23 They'll mostly be affecting northern parts of the UK.
03:26 And for many places, particularly on Thursday, it's straightforward.
03:30 Settled conditions, partly cloudy, sunny spells, one or two showers here and there.
03:36 But otherwise nowhere near as wet as it has been.
03:39 Temperatures rising with that high pressure.
03:41 Now, initially, temperatures are going to rise because the weather is settling down, because we've got that extra solar insulation.
03:49 But as you can see, things are starting to reshape themselves as we go into Thursday.
03:54 We've got the high pressure establishing itself to the east of the UK.
03:59 And we've got an area of low pressure emerging to the west.
04:03 Now, this is being carried along by an increasingly active jet stream.
04:08 And what you'll notice just to the south of the main low is another low that's starting to develop.
04:14 And that's quite significant. I'll talk a bit more about that in just a moment.
04:18 But let's talk about what happens when we have low pressure to the west, high pressure to the east.
04:24 Of course, the winds go anti-clockwise around low pressure in the northern hemisphere, clockwise around high pressure.
04:30 As a result, we're going to see this southerly airflow bringing increased warmth to the UK.
04:36 So let's take a look at some of the temperatures we might expect going into Thursday and Friday.
04:44 Skipping forward to Thursday. Now, these won't show exactly the kinds of valleys that we're going to be talking about,
04:52 because these are straight from the model. And what meteorologists do is they look at lots of different models.
04:57 And they think about also other factors that might lead to higher temperatures than what you're seeing on the computer model.
05:04 So these are fairly typical, I think, for Thursday. Low to mid 20s fairly widely, England and Wales.
05:11 Low 20s for Scotland and Northern Ireland. Into Friday.
05:16 And this is where we use our meteorological expertise to, say, think about other factors that might lead to higher temperatures than what the model is suggesting here.
05:27 One of them being that the graphic here is showing only a selection of sites and not necessarily the warmest spots.
05:34 But, yeah, fairly widely, I think, mid 20s across much of central and south-east England.
05:40 Low to mid 20s for Wales and for Scotland and Northern Ireland. We're talking about high teens and low 20s.
05:46 But in one or two spots for Scotland, there are some areas that benefit from a sort of fern effect and some extra warmth on days like this.
05:54 And so we could see mid 20s for parts of Scotland as well.
05:57 But in some of the warmer spots for parts of the south-east and east of England, then there is the potential for high 20s.
06:06 Talking about 27, 28 Celsius, for example. And if, and this is an if, if we get a lot of sunshine and winds in just the right kind of direction,
06:17 there's a chance of 30 Celsius in one or two spots. At the moment, it's assessed as a 20, 30 percent probability of 30 Celsius.
06:26 Most likely high will be the high 20s rather than 30 Celsius. But there's always that chance.
06:32 These aren't exceptional temperatures. They're not going to break any records, but certainly warmer than we've experienced during the past six weeks or so.
06:40 In more recent summers, these wouldn't necessarily be the kinds of temperatures that would be standing out particularly.
06:47 But I think they do stand out this week because, of course, the school holidays so far have been so much cooler and so much wetter than what we're going to see over the next few days.
06:57 Then an even bigger question mark into Saturday. Now, what looks most likely, and I'll talk about the thundery breakdown in a moment,
07:05 is that we're going to see a weather front sweep across the UK, bringing some thundery rain, some heavy rainfall in places and some showers,
07:11 and introduce less warm air and bringing temperatures back down towards average across, say, western parts.
07:18 You can see that 21 Celsius for Manchester, Dublin, Cardiff, Plymouth and so on.
07:23 But there's a chance that the warmth will cling on to the southeast.
07:28 So there's another day where there's a possibility of the mid to high 20s in places.
07:33 And Sunday again, actually, there's the possibility of 27, 28 Celsius, even when the technically cooler air has gone through.
07:43 It's not going to feel as humid on Sunday, but with a bit of sunshine and it will be a reasonable day in places with some sunny spells,
07:51 there's the potential for still above average temperatures, especially towards the southeast, closer to average towards the northwest.
07:58 What you'll notice here, Paris, Berlin, 30, 31 Celsius. We've got some hot air over the continent.
08:05 That's not going to be pushed away. That stays close by. And again, I'll talk a bit more about that in just a moment.
08:11 But let's take a look at the thundery breakdown. And there are still some uncertainties about this.
08:17 And it does hinge a little on the low pressure I mentioned, the secondary low.
08:22 There's the main low. That is a fairly developed feature. When these old lows or mature depressions, we call them, form,
08:30 there's less uncertainty attached to them because they've undergone their deepening and they just meander around or mosey about like an old dog.
08:39 That's going to be sitting to the west. But on the southern flank of that, there's this warm, cold gradient across the Atlantic that gets picked up.
08:49 You can see it marked out by a series of weather fronts picked up by the jet stream.
08:53 And really, it's as it comes out of Newfoundland that differences, very subtle differences, actually,
08:59 in different computer models start to emerge to do with how much it deepens.
09:04 Now, the Met Office model chunts it around the Atlantic just to the north of the Azores there.
09:11 And then watch what happens here. This is Thursday evening. It suddenly goes on to the cold side of the jet stream.
09:18 And that's the deepening side of the jet stream that allows it to spin up quite quickly.
09:23 And what we end up with late Friday. Let's pause it. Friday evening. Boom.
09:30 There we go. A really deep feature, actually. There are the weather fronts that are going to bring the change,
09:36 the outbreaks of rain, the thundery showers later Friday and into Saturday.
09:41 And there's the low attached to those weather fronts. A deep feature with tightly packed isobars and the potential for really quite strong winds.
09:51 But when we look at all these other computer models, the European model, the American model, for example,
09:58 none of them are showing a feature anything like that.
10:01 They basically put most of the energy into the mature low out to the west.
10:06 And this ends up as quite a weak feature that doesn't do much at all.
10:10 Still, some weather fronts bringing a thundery breakdown.
10:13 But the feature itself isn't going to be anywhere near as deep in these models.
10:18 And it's similar when you look at all the different runs of the Met Office model.
10:22 I'm just going to show you a snapshot of these. This is these are called postage stamps.
10:30 Because, well, they look like the kinds of things that could be on a letter.
10:34 And what each of these stamps show is a snapshot of the pressure at midnight on Friday going into Saturday.
10:43 So this is the same time for each of these, but from different computer model runs.
10:48 I appreciate it looks tiny on the screen. So you have to take my word for it if you can't really see it.
10:54 But one or two of these are showing a deep feature to the south of Ireland, bringing some very strong winds.
11:00 For example, the control member there.
11:04 That's the run that has the same characteristics as the high res model run, but with a lower resolution.
11:13 All the others have a lower resolution likewise, but they're slightly tweaked at the start.
11:17 So they have slightly different starting conditions compared with the operational, the high res computer model run.
11:23 And as a result, we can see how those tiny differences at the start manifest themselves as you go to three, four, five days ahead and so on.
11:32 And there are certainly some big differences that emerge.
11:35 We're all all of them as showing low pressure to the west of Ireland.
11:39 That's that mature depression. Some of them have this deep feature, but most of them don't.
11:45 So that's why we can say that higher resolution run that I just went through with a deep low to the south of Ireland is looking like an outlier.
11:53 It's looking less likely. You wouldn't entirely rule it out, but it is looking less likely.
11:57 So there's the chance of some very unsettled weather and some very windy weather associated with that.
12:02 But it's a low chance. What looks most likely is that the main concern will be the rainfall.
12:08 And let's just fast forward to Friday. This is the start of Friday.
12:12 We start off the day with a lot of low cloud. That's what this is showing here and some mist and so on.
12:18 And already the signs here of some showers breaking out across parts of Wales and southern England ahead of the main frontal system,
12:26 which at this stage is across southwestern parts of Ireland. But moving through.
12:32 Well, those showers are likely to disappear. We've got the heat building with the sun coming out a very warm day in places.
12:39 Then the main event appears late afternoon into the evening. Some heavy rain, some intense thunderstorms ahead of it.
12:48 They're likely to move up in the plume of warmth that's ahead of the front.
12:51 But either way, according to this model run, it all moves through quite quickly.
12:57 It moves through overnight Friday and by the start of Saturday, it's across northern Scotland.
13:02 And so we've got some heavy rains and persistent wet weather, a strong wind as well across northern Scotland.
13:06 Elsewhere across the UK, we're waking up on Saturday, having seen that rainfall overnight or the thunderstorms,
13:11 but brighter skies and a fresher feel. Now, timings at the moment are still uncertain.
13:17 So I wouldn't pin everything on that sequence of events happening at those times.
13:23 But the sequence of events is fairly likely. Outbreaks, rain moving in, some thunderstorms ahead of it,
13:29 some intense wet weather in places, some very high rainfall accumulations as well.
13:34 Exactly where and when still open to a little bit of uncertainty.
13:37 But we'll refine those details over the next few days. So that's the thundery breakdown.
13:42 Then after that, well, let's just play it to the end of the sequence here.
13:48 We've got the thundery breakdown moving through. Then we're back into a few showers,
13:53 but also plenty of sunny spells across much of the UK and actually a lot of fine weather into the weekend.
14:01 It's not going to be a particularly unsettled weekend like we've seen recently.
14:05 Once the main frontal system's out of the way, it clears the humidity through.
14:09 It's a fresher spell this weekend. There'll be a mixture of sunny spells and showers.
14:13 Most of the showers will be towards the northwest, driest weather towards the southeast.
14:17 Temperatures back towards average, but still the potential for high 20s towards the southeast
14:22 or at least 27 or so on Sunday. Fresher conditions, though less humid.
14:27 Now, in terms of beyond that, things are starting to take shape for next week in terms of the forecast.
14:36 But there is still some uncertainty about one particular aspect of the forecast.
14:40 I'm just going to show you that by highlighting London.
14:44 These are all forecasts for London, but they're forecast from a different time.
14:50 So the one on the right here, that's the most recent forecast.
14:53 The one in the middle, that's from 12 hours earlier.
14:56 And the one on the left, that's from 12 hours before that.
15:00 So what you can see is how the story for London has taken shape,
15:04 or at least how the forecast has changed slightly with the different computer models.
15:07 These effectively show the temperature at 5,000 feet, and that's important to look at
15:12 because that basically highlights the characteristics of the air without worrying about topography
15:17 or the shape of the land or the sea or the day/night differences and so on.
15:21 So you get a flavour for the temperature of the air mass rather than anything else.
15:26 And the temperature at 5,000 feet, basically it goes up there on the y-axis up to 24 or so Celsius at the top there.
15:36 And the forecast is out to next Thursday.
15:38 So what I'm showing here is the forecast from 52 different computer model runs of the European model.
15:45 And all of these different computer model runs are plotted on this graph.
15:50 But the bold line, that's the higher resolution operational run,
15:54 all the dotted lines that end up in this kind of smudge here that gets bigger with time because of the increased uncertainty.
16:01 Now, 36 hours ago, the operational model run had this big spike in temperature for next Tuesday.
16:10 Really quite an extraordinary heat wave. It showed really quite high temperatures at 5,000 feet,
16:16 but that would correspond to high temperatures, mid 30s or so at lower altitudes.
16:22 Now that showed up for Tuesday in this, but all the ensemble model runs were much lower.
16:30 The operational run was much higher than later this week's temperatures.
16:34 It was up there, but all the other runs were lower.
16:37 Now, what happened 12 hours later?
16:40 Same computer model runs showed for London again, that operational model run still showing this spike,
16:48 but more of the ensemble members edging up towards it.
16:51 That shows a bit more confidence that it is a plausible scenario rather than being an outright outlier.
16:59 Then we've got something in between. 12 hours later, we've got again this spike in the operational higher resolution model run
17:06 that's higher than the temperatures later this week, but not quite as high as 36 hours ago or 24 hours ago.
17:14 So it's still a spike in temperatures for London around Tuesday.
17:19 More of the ensemble members are heading that way as well, but it's not quite as high as the previous two computer model runs.
17:26 What does that tell us? Well, you'd have to look also at Glasgow, which doesn't show that at all.
17:33 It shows the main spike. Glasgow is on the bottom, by the way. London's on the top for comparison.
17:39 Main spike is Friday and then it just goes down.
17:42 All these different computer model runs aside from one or two lower resolution ensemble members.
17:46 So Glasgow doesn't show that signal for higher temperatures on Tuesday.
17:51 That's one key difference. And really, it's mainly just the South and Southeast that is showing the possibility of some heat
18:01 from the continent pushing back towards the South and Southeast of the UK.
18:06 The rest of the UK likely to avoid that. So this sums up. There's the UK there.
18:12 And all these different lines, the red lines here, show the position of a warm front for next Monday.
18:20 And as you can see, these are called spaghetti plots for obvious reasons.
18:24 As you can see, loads of different positions for the warm front, but around 30, 40 percent of them show the warm front over the southeast of the UK.
18:34 And that warm front is bringing, if it did arrive into the southeast of the UK, is bringing hotter air, but also the chance of some thunderstorms.
18:41 So that's how we can say that for the start of next week, Monday, Tuesday, there's around a 40 percent chance that hotter weather will return to the south and southeast of the UK.
18:53 Not much of a chance for the rest of the UK. So there's that possibility for the start of next week.
18:58 And just to show you how that might look on these maps, which show the likely weather patterns, this is the most likely weather pattern for next Monday.
19:07 And this is the most likely weather pattern for next Thursday. Looking at next Monday, we've got low pressure just to the south of Iceland.
19:13 A changeable weather pattern for Scotland, Northern Ireland, sunshine and showers, average temperatures.
19:19 For the southeast, we've got an area of rain, which with temperatures of 26 Celsius, therefore the southeast, which could be quite humid, could be thundery rain coming from the continent, could be quite elevated temperatures in the southeast.
19:33 Excuse me. Talking too quickly. But whether or not that happens, we then move on to the most likely regime or weather pattern for the end of next week, which shows higher pressure across much of the UK.
19:51 Still some showers there for the northwest, but back to around average temperatures, the heat from Europe gone away and back to fairly benign conditions.
20:01 And just to finish on this, this shows the probability of pressure or pressure anomaly above zero.
20:11 Essentially, the reds are where you're likely to have higher than normal pressure. The blues are where you're likely to have lower than normal pressure.
20:16 And this is through next week. We've got reds across the UK more likely to have higher than normal pressure through next week.
20:23 So what I'm saying is next week looks mostly fine. There'll be some showers for the northwest of the UK, a bit blustery here at times.
20:31 Towards the southeast, Monday, Tuesday, there's the potential for that plume of heat from the continent and some thunderstorms.
20:38 But after that, it looks like things will settle down for a few days. And after that, into the start of September, this is the most likely or at least the pressure anomaly.
20:49 And it shows no signal really at all for the UK. And by that stage, it's 50/50 whether we get higher pressure or lower pressure.
20:56 Very low confidence by the start of September, which, of course, is also the peak of the hurricane season.
21:02 And that can often throw up a few wobblers. So, yeah, a lot to keep us interested over the next few days.
21:09 Of course, we'll refine the details of this weekend's weather closer to the event and into the start of next week, whether or not we get that thundery and hot plume into the southeast.
21:20 But a lot of fine weather signalled either way for later this month before we get into meteorological autumn.
21:28 Thank you for joining me for the deep dive. Hope you enjoyed it. Hope you found it useful.
21:32 If you did, don't forget to hit like, send us a comment, send us a suggestion and hit subscribe if you want to follow more of these in the future.
21:41 Bye bye.
Recommended
2:53
0:56