- 5 weeks ago
This is an in-depth Met Office UK Weather forecast for the next week and beyond.
After an extraordinarily dry and hot summer widely across the UK - especially England and Wales - how much rain do we need to get back to normal? And how much rain will we get in the next few weeks?
Bringing you this deep dive is Met Office meteorologist Aidan McGivern.
After an extraordinarily dry and hot summer widely across the UK - especially England and Wales - how much rain do we need to get back to normal? And how much rain will we get in the next few weeks?
Bringing you this deep dive is Met Office meteorologist Aidan McGivern.
Category
🗞
NewsTranscript
00:00The serious consequences of this extraordinary summer can be seen and felt across much of the UK, especially England and
00:07Wales.
00:08We certainly need a lot of rain to relieve the situation. How much rain do we need? And are we
00:13likely to get it any time soon?
00:15Welcome to the Met Office Deep Dive.
00:18Thank you for joining me this week. We do these regularly every Tuesday.
00:21They are in-depth looks at the weather across the UK and if you enjoy 20 to 30 minute weather
00:30forecasts that look at the more technical aspects of meteorology sometimes and try to explain the weather that has just
00:36been and the weather that is to come, please do give us a follow if you're not already.
00:41Spread the word. If you know other people who might like these, ask us a question.
00:45We like to answer them in the Weather Studio Live, which is another video that we do regularly on a
00:50Friday lunchtime.
00:52But enough on that. Let's get stuck in.
00:55And before I talk about the rain, let's talk about the heat because we've just gone through yet another remarkable
01:01heat wave.
01:02And in fact, I see this summer as being bookended by two reasonably extreme heat waves, both of which saw
01:1038 Celsius recorded or exceeded.
01:14And that's marked for the June heat wave, the earliest 38 Celsius on record by three weeks.
01:22And for the August heat wave just last week, the latest 38 Celsius recorded by a matter of three days.
01:31So 38 Celsius, we might have gotten used to in this summer temperatures into the mid 30s and beyond.
01:39But it's worth emphasising how unusual these kinds of temperatures are.
01:43Of course, in the 1980s, 35 Celsius wasn't recorded once.
01:47We've recorded it lots of times this summer.
01:5038 Celsius, these two extreme heat waves that bookended the summer with several heat waves in between, of course,
01:57of a slightly less severe and less widespread nature.
02:01But I thought it might be interesting to compare the two heat waves because in many ways they were very
02:06similar,
02:07both in terms of their maximum temperatures and the main mechanism behind the heating.
02:11But also they were quite different in when it comes to humidity, especially in terms of the impacts and and
02:21the forecasting challenges as well.
02:23Let's start off by looking at the heat wave that peaked on the 26th of June, 2026.
02:30Here's the synoptic map.
02:32And I know whenever we show these black and white synoptic charts, people say they can't see them very clearly.
02:38But I don't draw them. It's the best I can do right now, I'm afraid.
02:42I'll try and make it easy by pointing out where the UK is.
02:45Here we are in the middle.
02:46And then the solid black lines here with the spiky things on them.
02:50Those are weather fronts and so on.
02:52There's a big H here over Denmark.
02:54So high pressure was to the east of the UK, as you'd often expect when you get a extreme heat
03:01wave in the UK.
03:03You typically have high pressure at the surface close by, especially to the east.
03:08And then an upper high as well, which, well, you can just about imagine extends right the way up into
03:14Scandinavia as this high pressure builds northwards.
03:17And the high pressure was drifting eastwards with these troughs coming into parts of the southwestern Wales.
03:23So the 26th of June, although that's the day that's 38.0 Celsius, was recorded in Lingwood, Norfolk.
03:30It was cooler than the day of the preceding days across western parts of the country.
03:35A change was on the way.
03:36But on this particular June heat wave, the primary mechanism for heating the air and for those extraordinary high temperatures
03:47was sinking air,
03:49as is normally the case for heat waves in the UK.
03:53Under high pressure at the surface and high pressure higher above, the air was becoming compressed,
03:57just like when you pump up your bicycles, that compression led to higher temperatures wherever that air was sourced from.
04:05More on that in a moment.
04:06Very similar pressure chart for 13th of August, which is the peak of last week's heat wave.
04:11High pressure again to the east.
04:13A big upper high also sitting just to the east of the UK.
04:18So we've again got that main heating mechanism.
04:21Air sourced from elsewhere was sinking and being compressed under high pressure.
04:28That's the primary cause for the higher temperatures.
04:30It was not the only cause because what also helped under sinking air was that there was very little cloud
04:36development.
04:37So we had strong sunshine both in June and in August.
04:42And that's, if you like, was the icing on top of the cake because that added additional heat, the solar
04:50insulation.
04:51But of course, in that situation, June had the edge because the sun was so much stronger in June, close
04:57to mid-summer, about as strong as it gets.
05:00Less strong mid-August.
05:03But a few other differences important to take into account for these two heat waves.
05:07And one is where the air was being sourced from.
05:10And this is really quite stark, the differences between the two situations.
05:14And again, I'm sorry for the quality of these charts.
05:17It's the best I could find in a reasonably short space of time earlier in the day.
05:23But the UK is here.
05:26And this chart on the left shows where the air came from for the peak of the heat in June.
05:31And the air on that day at lower levels is shaded in darker blue.
05:39And you can trace the lines back to discover that the air on that hottest day back in June came
05:46from Iberia, sort of just across Portugal, perhaps parts of the Atlantic or the Bay of Biscay.
05:54So the air was sourced from lower latitudes and as a result, it had pretty high potential.
06:02It already started off warm and then it was drawn into the high pressure, compressed.
06:07That added a lot of the heating and ended up being heated by the sun over the UK.
06:13So not necessarily heated by the sun directly.
06:17I'll talk more about that in a second.
06:18So lots of potential where the air came from in June.
06:22The air in August last week came from a very different location.
06:26The darker blues, you can see, the day or two before it came from northern France and the low countries.
06:32But before that, it came all the way back from Iceland.
06:35And in fact, some of these lines go all the way to the Arctic Circle.
06:39So the air was sourced from cooler and less humid locations.
06:44It had lower potential compared with June.
06:47So if you're just taking the starting potential of the air, June, much higher potential.
06:55However, also higher humidities.
06:58And the difference in humidities was very large.
07:02You might have noticed that experiencing both heat waves yourselves.
07:07And another thing that caused the June heat wave to be more humid, of course, was that the first half
07:12of June was especially wet.
07:14We had above average rainfall.
07:16It's easy to forget now.
07:17But the first two weeks of June were wet across large parts of the UK.
07:20We had lots of weather systems going through some heavy rain at times.
07:24Then, at the start of the week in question, the heat peaked on Friday, remember, at the start of that
07:30week, there was this large area of thunderstorms, thundery rain that crossed the south of the UK.
07:35So actually, the ground was moist.
07:38And that added to the humidity, but also took away from the resultant temperatures.
07:46So I mentioned just a minute ago, incorrectly, of course, that the sun heated the air.
07:51It doesn't heat the air.
07:52It heats the ground.
07:53And the ground then heats the air.
07:54That's what happens.
07:55Strong sunshine heats the ground.
07:57The ground then heats the air.
07:58Now, if the ground is wet, a lot of that solar energy is going to evaporate the moisture in the
08:03soils before it then goes on to warm up the ground.
08:06And then that heats the air.
08:08So if you've got this high potential air coming from the south, getting compressed under high pressure, strong sun, but
08:15then a lot of the energy is going to evaporate the water on the ground that's just fallen in recent
08:20days and weeks, then the potential is not quite reached.
08:23And the computer models, this is interesting, the computer models that week, you may remember this, were forecasting temperatures of
08:3040, 41, 42 Celsius as the maximum temperatures that week.
08:35Now, our experts in the operations centre here at the Met Office didn't expect temperatures to reach those kinds of
08:43values because these computer models have been known to overestimate how dry the soils are.
08:50And so they were assuming that the soil was relatively dry.
08:53They weren't factoring in those earlier thunderstorms.
08:56And as a result, with that potential air mass and the strong sun and so on, the models were thinking
09:04temperatures are going to go up to 40, 41, 42 Celsius.
09:07And the air temperature potentially would have done if so much of that heat from the sun wasn't lost through
09:13evaporating the moisture.
09:15So the chiefs upstairs fully expected the models to be overestimating things, and the most likely maximum temperature that week
09:23in our forecast was 39 Celsius.
09:26Not in the apps, of course, that's automated data.
09:29A lot of people saw 40, 41 Celsius in various weather apps.
09:32But the official forecast that we were giving in our presented videos and other locations was 39 Celsius as most
09:39likely high.
09:40Of course, it ended up being 38.0 Celsius, so even lower than the models were suggesting.
09:47Then we got to last week, and the models weren't overestimating how dry the soils were because, of course, they're
09:54about as dry as they can get.
09:56So we had more confidence that the models were correct when they were suggesting maximum temperatures last week of a
10:03smidge under 38 Celsius.
10:05In fact, in the days preceding the 13th of August, the chiefs, deputy chiefs, realised that the models were actually
10:13underdoing temperatures each day by about half a degree.
10:16So they upped them and said the most likely temperature on Thursday the 13th would be 38 Celsius.
10:21And that temperature was realised at 38.1 Celsius at Kew Gardens, for example, at 38.0 for Pershaw in
10:30the Midlands.
10:30So, yeah, two similar situations, high pressure, sinking air, compression, strong sun.
10:38But the potential in June was far greater because of the source of the air.
10:43And at the same time, the humidities were greater in June.
10:47There was more moisture at the surface and in the air, of course, as well, which we all felt.
10:53That meant that we ended up with very similar maximum temperatures in both situations.
10:57But we also ended up with very different impacts.
11:00Now, with higher humidities in June, it was much more oppressive, much more difficult for we humans to deal with,
11:07for us to cool down, for our homes to cool down and for our bodies to get some relief.
11:12It wasn't just very humid by day.
11:16It was hotter by night compared with the August heat wave.
11:19The temperatures weren't dropping away so much.
11:22And as a result, we ended up with a red extreme heat warning and really significant health impacts, which are
11:28estimated to have caused in excess of 2,000 excess deaths in that June heat wave.
11:33So, tragically, health impacts were serious back in June because of that humidity, because of the overnight temperatures and the
11:43very high daytime temperatures.
11:45Conversely, it was a little more challenging for meteorologists to assess the kinds of impacts they were expecting last week
11:54because of such lower humidities.
11:56Now, to compare the two, in June, the humidities or the dew points were typically in the low 20s in
12:04places.
12:04That's really quite high for a dew point temperature.
12:08Last week, during the peak of the heat, dew points were 8 to 10 Celsius, which is more similar to
12:14the July 2022 heat wave when 40 Celsius was recorded.
12:19So, a dry heat.
12:21Less impactful on health compared with the June heat wave.
12:25So, less certain how widespread health impacts were going to be last week and less long-lived with a bit
12:32more relief by night.
12:34So, those are the positive things.
12:35However, we saw the serious consequences of wildfires developing because, of course, the state of the ground across many parts
12:43of England and Wales and this dry heat, this surge in temperatures,
12:47which led to devastating scenes in many parts of the UK, especially through the Midlands.
12:5219 homes, sadly, destroyed.
12:54And, of course, that then led to a ban on disposable wildfires.
12:59So, two extreme heat waves differing primarily in the source of the air, the soil conditions and the resultant humidities
13:09and impacts.
13:12Not just that, but they differed in terms of how widespread the heat was.
13:17This graphic, you might be able to see it, but I'll guide you through it.
13:21It shows the percentage of the observing network reaching 36 Celsius or higher since 1931.
13:28And, basically, it shows how widespread those temperatures have been for various heat waves.
13:34Number one, unsurprisingly, in the 19th of June 2022, when almost a third of the observing network across the UK
13:42recorded 36 Celsius or higher.
13:46Number two, significantly lower than that extraordinary day back four years ago.
13:51Number two, close to 18% the day before we hit 40 Celsius, 18th of June 2022.
13:59But number three was last week, 13th of August 2026.
14:05The third highest percentage of the observing network reached 36 Celsius or higher.
14:10And that was just a smidge over 15% of the observing network reached 36 Celsius or higher.
14:18And then, in fourth place, you've got 25th of July 2019.
14:22That's when the UK temperature record was beaten before we got to 40 Celsius.
14:26And then, in fifth place, you've got 26th of June 2026.
14:33And we've talked a lot about the occurrences this year of different temperature thresholds.
14:39We've covered it in detail, so I'm not going to go through it again.
14:42But it's safe to say that for virtually every temperature threshold from 28 Celsius up to and including 37 Celsius,
14:512026 is number one.
14:53Joint first for 38 Celsius or above.
14:57Joint first with 2022, of course, two days.
15:00And only the second year that 38 Celsius had been recorded twice.
15:04So, all these temperature thresholds have been exceeded this year.
15:09And it's been such an extraordinary summer for the amount of days of 30 Celsius, 32 and so on.
15:16This graphic shows how it compares with previous years.
15:20There are some standout years and I appreciate it again.
15:23It's a graphic that might take some getting used to and you might need to squint a bit.
15:29But I'll get you through it.
15:30This is the number of days different temperature thresholds have been reached each year since 1931.
15:37The year's going from 1931 on the left all the way up to 2026 on the right.
15:42That's 2026.
15:43And there are three colours involved here.
15:44The white is the 30 Celsius.
15:47This colour, whatever it is, I'm colour blinded on what it is.
15:50Red, orange, brownie kind of colour.
15:52I don't know.
15:52The middle colour is 32 Celsius or above.
15:55And then this blue kind of colour.
15:57Or maybe it's purple.
15:58I don't know.
15:59But you tell me.
16:01It's on the bottom.
16:02That's 35 Celsius.
16:04And for those three temperature thresholds, they exceed every other year since 1931.
16:10And then combined, they exceed every other year.
16:12A couple of standout years.
16:13Obviously, 1976, 1975 as well, here in the middle.
16:181995 is the big one.
16:19A lot of those temperature thresholds were previously reached in terms of how frequent they were in their records in
16:261995.
16:28But we've had this upward trend, albeit sporadic, in the last few years.
16:33So quite a chunk of recent years have been reasonably high for all these temperature thresholds.
16:37Another notable one there, 2018.
16:39You may remember that one.
16:41Long, hot summer.
16:45So those records have already been broken a number of times certain thresholds have been exceeded for this summer.
16:53But what we don't know yet is whether it's going to be the warmest summer on record.
16:58We can have a good guess and we can talk about how likely it is.
17:01And that's what this table of numbers shows us.
17:05And there's a lot of numbers to get your head around here.
17:06So I'll just pick out key ones.
17:08We've got the area down the left-hand side, UK, England, Wales, Scotland, etc.
17:13And then we've got the actual mean temperature.
17:16That's the first column of numbers.
17:19Now, mean temperature, that means the average of the overnight minimum and the daytime maximum.
17:26And it's currently showing for the UK 16.65.
17:30That's up to and including yesterday, 17th August.
17:33How does that compare with the warmest summer on record?
17:37Well, that currently stands as last year, which was 16.12.
17:41So currently running above that, quite significantly above.
17:44So if we stopped here, obviously it would be number one warmest summer on record for mean temperature.
17:49But we're not going to stop here.
17:50It is going to get cooler over the next few days.
17:53Will that prevent it from being the warmest summer on record?
17:57Well, this number in the far right corner tells you how much warmer or cooler the rest of August would
18:07need to be compared with summer overall to be the warmest summer on record.
18:11And it's saying the anomaly to equal the record is minus 1.95.
18:15In other words, if the anomaly for the rest of August compared with summer is minus 1.95, it will
18:22equal last year's warmest summer on record.
18:25If it's slightly warmer than that, if it's an anomaly of minus 1.9, minus 1, you know, a degree
18:330.9 below average for the next couple of weeks, it will be the warmest summer on record.
18:40So it's, we mentioned this last week, it's likely to be the warmest summer on record for mean temperature in
18:49the UK, unless it ends up being 2 degrees below average for the next couple of weeks.
18:55That's the UK.
18:57A couple of other things to point out.
18:59All of these regions across the UK are number one, except Northern Ireland, which is currently running at second warmest
19:06on record, despite it being quite wet at times this summer.
19:09And Scotland, you might be surprised to hear, nowhere near as exceptional as England and Wales, but still running at
19:16seventh warmest summer on record.
19:19Again, could change significantly in the next couple of weeks.
19:23It's just showing where things currently stand.
19:26Now, maximum temperatures.
19:28So I talked about mean temperature there, and that's interesting because it's maximum combined with minimum.
19:35But if you just take maximum temperatures, again, the same sort of table here.
19:39UK at the top, top row, and it's showing the current actual maximum temperature averaged across the UK is 21
19:47.54 Celsius.
19:50The record stands at 1976.
19:54This is a longstanding record maximum temperature for summer in the UK.
20:00And even though 1976 is sixth in the list of warmest summers when you take into account nighttime temperatures as
20:10well as daytime temperatures,
20:11because we've had a lot of summers in recent years that have had warm nights as well as warm days,
20:16the maximum temperature hasn't been broken yet.
20:20As things stand this summer's on course to beat that, it would need an anomaly of minus 1.29 Celsius.
20:29In other words, if it's a degree or a little bit above below normal, if it makes sense of it,
20:37if it's just a bit more than a degree below normal for the rest of summer, it will beat 1976.
20:43Again, no guarantees, this is just where things currently stand.
20:46We've still got a couple of weeks left to go.
20:50But what's even more remarkable is when you look at some of these bigger numbers,
20:55the anomalies you need to beat the record,
20:57you go down to the south of England and the actual maximum temperature averaged so far this summer is 25
21:05degrees.
21:05That's an anomaly of four degrees.
21:08In other words, across the southern half of England,
21:11maximum temperatures on average up to the 17th of August have been four degrees above average.
21:19And around a degree and a half above the previous record, 1976,
21:25you'd need a temperature of less than, or you'd need a temperature of more than six degrees below average for
21:35the rest of summer
21:35for the south of England, not to beat the record set in 1976.
21:41So really remarkable numbers coming through there for southern parts of the UK
21:47and how anomalous the maximum temperatures have been.
21:51I looked at a few sites in particular and the average maximum temperature for London, for example,
21:58so far this summer has been 27 degrees.
22:00That's more than four degrees above average for London.
22:05That would be similar to an average summer somewhere much further south across Europe,
22:10somewhere like Nice or Lisbon.
22:12So extraordinary maximum temperatures, especially for the south of the UK.
22:17It has been a warm summer for Scotland,
22:19but it's also occasionally been a wet summer, not the whole time.
22:24This shows the total rain, how it compares with average
22:29and how it's accumulated through the season up to the 17th of August.
22:33And you can see the line up and down against the average, which runs through the middle.
22:38And actually, it's pretty much bang on average for the whole of Scotland.
22:42Some wetter periods, some drier periods.
22:43So at the moment, for Scotland as a whole, running at average, but that masks significant regional differences.
22:51Northern Scotland currently running at well above average by around 70 to 80 millimetres.
22:57Eastern Scotland running at well below average.
23:00So big regional differences.
23:01I'll have a map in a moment showing this.
23:03Big regional differences across Scotland.
23:05Northern Ireland only just dipped below average for summer so far.
23:10You can see that line.
23:11It's flatlined for a bit after some wetter weather through April into May and into June.
23:19Actually, I'm talking about summer.
23:20What these graphs are showing is perhaps more useful than talking about summer.
23:25It's the period from the 1st of April up until the end of September.
23:30So it's this period in which you predominantly get a deficit in rainfall anyway.
23:37In other words, you get less rainfall, you get more evaporation, you get more transpiration by plants and so on.
23:42So this is the period of the year when you typically get a deficit in soil moisture and things like
23:49that.
23:50And it just shows you whether that's been on track or whether it's been more extreme compared with what you'd
23:56expect.
23:57So Northern Ireland currently running at a deficit in rainfall since the 1st of April.
24:02Nowhere near as much of a deficit compared with England and Wales.
24:06And you can see one or two wet periods since the 1st of April, an awful lot of dry periods.
24:14Just point out one wet period.
24:16Again, you might have forgotten this.
24:18Last few days of May into the first 10 days of June.
24:22And you can see how that line, which shows the accumulated rain since the 1st of April, it goes quite
24:29steep upwards.
24:31So quite significant rain as summer began.
24:34And since that time, 10th or 11th of June, it's basically a flat line across England and Wales.
24:40Barely a drop of rain in many places.
24:43In fact, remarkably, 61 dry days at the last count for Wisley, I think.
24:54Wisley.
24:56If it's not, I'll write a correction in the comments.
24:58It's just off the top of my head.
24:59I think Wisley.
25:01Check the comments and see if I'm right.
25:02I'll post a correction if not.
25:05So basically flat line since the 10th or 11th of June.
25:09And now we've got this disparity.
25:11And I make that around 150 millimetres of rain deficit since the 1st of April.
25:20About that much.
25:22And it does vary, obviously, from place to place.
25:24I've looked at a few individual counties.
25:26For example, Berkshire, it's closer to 190 millimetres deficit since the 1st of April.
25:32Other places, it's more like 100, 100, 10, 120 millimetres.
25:37But as a rule of thumb, let's just call it 150 millimetres deficit in rainfall across England and Wales since
25:44the 1st of April.
25:45So a very dry spring followed by a very dry summer with one or two wetter spells.
25:53It's a little bit too simplistic, I would suggest, to just say, now we need 150 millimetres of rain to
26:00make up for the deficit.
26:02A couple of reasons for that.
26:03One is that, obviously, there's this big place to place variation.
26:08Western Scotland, again, this is April to July, this map shows, how rain compares with what you'd expect for April
26:14to July, that four-month period.
26:16It's been wet for Western and Northern Scotland, dry for Eastern Scotland, and very dry in some parts of the
26:23Midlands.
26:23Eastern England, Central Southern England, less than 30% of its rainfall in that four-month period.
26:30You're probably not surprised to hear that.
26:32So big regional variation.
26:34And it's not just about the deficit of rain, either.
26:38It's about what happens to the moisture when it's on the ground.
26:41So if it's sunnier and hotter than normal, then so much more evaporation takes place.
26:48You need even more rain than you'd normally need to replenish the dry ground.
26:52And it has certainly been a sunny and hot period.
26:56This shows, same period, April to July 2026, sunshine.
27:00How it compares with average for the same period, virtually everywhere, away from the northwest of Scotland, average or significantly
27:07above average sunshine during that period.
27:10More sunshine, more evaporation, drier soils, and more heat, of course, as well.
27:15Well, large part of England and Wales, two degrees or more above average.
27:20And as I mentioned, this is maximum temperature.
27:22As I mentioned, some parts of the south through the summer, not from April to July, which the map shows,
27:29but through the summer have been four degrees or more above average for maximum temperatures.
27:33So, yeah, we've had 150 millimetres less rain than you'd expect since April across much of England and Wales, more
27:42in some places.
27:43But that combined with the fact that it's been sunny and hot means that so much more of it has
27:48evaporated, leading to even more of a sorry state in terms of dry ground across a large part of England
27:57or Wales at least.
27:59So, we need a lot of rain, in other words, to make up for this deficit.
28:05Big question is, will we get it?
28:07Another thing to bear in mind when we talk about the lack of rain since April is how wet it
28:14was from October to March last year.
28:17This shows the amount of rain and how it compared with the middle black line there, the average, through October
28:24to March.
28:25And you can see how it accumulated and accumulated.
28:28And this big chunk of blue above the average line in the middle appeared by the end of it, which
28:34isn't far off 150 millimetres on top of what we'd normally expect.
28:40So, we've swung from one extreme, of course, with rain day after rain day, and we're talking about two months
28:46of consecutive rain days, to another extreme, where we've seen dry day after dry day, and now talking about two
28:53months of consecutive dry days.
28:55There's an excess of 100 to 150 millimetres of rain during the wetter part of autumn and winter, and then
29:04a deficit of a similar amount of rain during the hotter, drier part of the year.
29:10So, we've gone from one extreme to the other.
29:12The question is, will we go back to this next extreme, when autumn begins?
29:20Well, there are a couple of things to bear in mind, and the most important is that autumn and winter
29:27weather in the UK is highly variable from year to year, from place to place.
29:31A lot of random variability very much depends on the track of lows, the shape, and the track of the
29:37jet stream, and so on.
29:39A couple of things, though, very warm seas at the moment, that would, you'd think, encourage a bit more evaporation,
29:47a bit more moisture in the air, a bit more energy.
29:51Another thing, El Nino, of course, which increases the chances, loads the dice towards wetter and windier weather in the
30:00autumn and early winter, doesn't guarantee it at all.
30:04It's not like every time there's an El Nino, we get that weather, it just increases the chances of it,
30:10loads the dice towards it.
30:13So, yeah, there's a point at which we could make up.
30:18If we had that rainfall that we had last autumn and into the winter, there's a point at which that
30:24deficit could be made up.
30:25But it's not going to happen overnight. It's certainly not going to happen this week.
30:31Because, yeah, although you might have heard there's some rain expected over the next few days,
30:36and I suspect a lot of you will enjoy going out and standing and feeling the rain again across many
30:41parts of England and Wales where it's been seriously lacking,
30:44it's not going to be the most useful rain.
30:46First of all, it's not going to be a huge amount.
30:48And secondly, it's mostly going to be quite showery, so highly variable amounts across the country.
30:51What's going on? Here's the UK at the time of recording.
30:56Quite a powerful jet stream crossing the country. Not something we've seen for a while.
30:59Low pressure, close to the northwest of Scotland. Weather fronts swinging south.
31:04And if we put on a summary of these various charts, we can see what happens and the general setup
31:13at the same time.
31:15First front to keep an eye on, this front, bringing a spell of rain into Northern Ireland, much of England
31:21and Wales.
31:21Overnight. So, yeah, this is the first chance of reasonably widespread rain for those areas that desperately need it.
31:28But it's not going to be much rain. It's mostly light to moderate.
31:31It moves through. It's drier then by Wednesday.
31:34At this point on Wednesday, we've got low pressure over the northern half of the UK and a lot of
31:39showers pushing into Western Scotland,
31:41Northern Ireland in particular.
31:43That's where the most frequent downpours will be. Heavy with thunder and hail.
31:47They'll be rattling through one after the other.
31:49Plenty of rain in Western Scotland and Northern Ireland.
31:53Showers elsewhere, but fewer and further between.
31:55Even across parts of England and Wales, there'll be showers moving through.
31:58Some heavy downpours, but not a great deal.
32:01Sunshine in between.
32:02It's been certainly feeling cooler on Wednesday afternoon compared with recent days.
32:06Now, skipping ahead to Thursday, and the good news if you're after rain in the south is that there'll be
32:12some more substantial showers moving through on Thursday as low pressure tumbles southwards.
32:18Jet stream dips, that brings, again, cooler air, not just at the surface, but higher up.
32:23That causes more instability in the atmosphere, causes some of these heavy downpours.
32:27Quite slow moving to affect parts of northern England, north Wales at first in the day, and then the liveliest
32:33showers push south.
32:34Many places getting a downpour on Thursday.
32:36If you just want to stand out in the rain and try and remember what it feels like, Thursday, good
32:41chance of getting hit by a sharp shower.
32:45Now, all the while, very variable rain accumulations, and even more so is going to Friday.
32:51Still some instability in the atmosphere.
32:53At this stage, we've got weather fronts moving through the south of the UK.
32:56Quite a picture further north.
32:57High pressure trying to build in, but it's going to take some time.
33:00We've still got a dip in the jet stream over us, so we've still got this cooler air higher up
33:04in the sky, causing instability.
33:07Plenty of showers then, especially in the east and western coastal areas, and for the southwest.
33:11Yes, some slow moving lively downpours.
33:15Saturday, let's show the bigger picture of this, because I think it's quite interesting.
33:19We've got this dip in the jet stream.
33:21Look at that.
33:21You can just about make it out.
33:23So that indicates we've got an upper low, where the jet stream is, out towards the southwest of the UK.
33:29At the same time, we've got surface high pressure moving in.
33:32So that's going to settle things down gradually this weekend from the north.
33:36But with that dip in the jet stream across the south, well, that's why we're going to see quite a
33:42few showers across the southwest, western parts of the world.
33:45Elsewhere, plenty of fine weather.
33:46Into Sunday, many of those showers get killed off.
33:49As the high builds in, things turn drier and sunnier.
33:54Not that warm, though.
33:55We've got this legacy of cool air.
33:58And let me show you the temperatures and how they'll compare over the next few days.
34:02These are maximum temperatures, which have been so extraordinary this summer so far.
34:07Still well above average across the south on Tuesday.
34:10Back to average on Wednesday.
34:11Below average on Thursday.
34:13And into Friday, we're talking about mid to high teens in the north.
34:15High teens, low 20s in the south.
34:17High teens, similar on Friday, if not a little bit lower.
34:19You can see how that compares to the average by this summer here.
34:22Tuesday, Wednesday, Thursday, Friday.
34:24Much of the UK below average by Thursday and Friday.
34:28Blues widespread.
34:30Very few days this summer have had below average daytime temperatures.
34:34So that's certainly going to be noticeable.
34:37And perhaps welcome for many people.
34:41But the rain, although welcome, not going to immediate.
34:48Fixed the situation overnight.
34:50You wouldn't expect it to, given the serious deficit we've built up over the last few days.
34:55A few days?
34:56Two months.
34:57And this shows the amount of rainfall, the total amount of rainfall out to the next five days.
35:02Let's skip ahead to Saturday.
35:04The map turns bluer.
35:06All areas seeing at least some rain.
35:09Where are the wetter spots?
35:11Northern England.
35:13Northwest England there.
35:14Yeah, that's because of the very lively showers that we start off Thursday.
35:17Could cause some issues, actually.
35:19Yeah, it has been very dry this summer.
35:21But that doesn't mitigate against issues caused by some heavy rain in a short space of time.
35:26Thursday morning, northern England, north Wales.
35:28That's where the brighter colours are there.
35:30100 millimetres, perhaps.
35:31But further south, some darker blues, indicating 50 millimetres or so over the next few days.
35:40We're very speckled in nature.
35:41So really variable rainfall totals.
35:44Not the most useful form of rain during coming days.
35:49You'd expect, as we go deeper into, say, September and October, the rain will become increasingly, in terms of fronts,
35:58big bands of rain, rather than showers.
36:02But at this time of year, a lot of the rain comes in showers, of course, so it's very hit
36:06and miss.
36:07Speaking of going into late August, September, October, autumn is approaching.
36:15And the big question is, are we going to see a more permanent change in fortunes?
36:20Because you might have spotted this weekend high pressure moving back in.
36:26And you might have seen newspaper headlines that talk about another heatwave on the way for the start of September.
36:32Well, let's just say, the reports of a heatwave are overblown at the moment.
36:36And this high pressure isn't expected to last more than a few days.
36:41It's going to bring a lot of dry weather early next week, which is what this graphic shows.
36:45This shows the most likely weather patterns for the next couple of weeks.
36:48And it shows blues for the time being.
36:51Blues are where you have low pressure close to the UK.
36:55Reds and oranges are where you have higher pressure close to the UK.
36:57So, we've got the blues next couple of days because, of course, we've got low pressure toppling across the country.
37:03Then, Sunday, Monday, Tuesday, Wednesday, more of these reds, which indicates high pressure close to the UK.
37:11In terms of high pressure and where it's likely to be, it's going to be toppling southeastwards across the country
37:18early next week
37:18and ending up to the east of the UK with low pressure slowly approaching from the west.
37:24But here's what has caught my eye.
37:26These darker blues are starting to flirt with the bottom right corner of the map.
37:33Those darker blues are westerly dominated weather patterns.
37:37These lighter blues are where you've got low pressure bringing northwesterly winds.
37:43And a lot more of these blues in general starting to appear for the last few days of August.
37:48What does that look like?
37:50Well, if we skip forward to, for example, Monday the 31st of August, last day of meteorological summer,
38:00most likely weather pattern has low pressure over Scotland, a westerly breeze for all areas and below average temperatures.
38:08That's what that shows with, this is what this shows, blues above average rainfall, most likely.
38:16Second and third most likely weather patterns.
38:19Again, low pressure close to the UK.
38:21In this one, it's to the northeast.
38:23In this one, it's directly over the UK.
38:24I'm starting to see more and more very unsettled weather patterns from the middle of next week for the last
38:32few days of August and for the start of September.
38:36That's what seems to be coming through.
38:38That's what's summarised when you look at these charts.
38:41These charts basically look at all the model output, hundreds of model runs, and suggest the most likely weather patterns.
38:48And this is the kind of flavour that is starting to come through.
38:53Last few days of August starts as September.
38:55We're not talking about showers.
38:57We're talking about low pressure, very close to the UK.
38:59We're talking about an increase in the breeze.
39:01We're talking about below average temperatures, perhaps.
39:03We're talking about active weather fronts moving through.
39:06And if you desperately need the rain, and we obviously need an awful lot of the wet stuff, then that
39:14would be welcome news.
39:15But, of course, we're talking about the middle of next week onwards, so it's not in what we call the
39:21reliable time frame for weather forecasting just yet.
39:24I'll look at it a bit more in the 10-day trend tomorrow.
39:28There are promising signs there, not of another heat wave, which is what some of the headlines are suggesting,
39:34and not of that high pressure this weekend lasting for more than a few days,
39:38but of something turning up that is a lot more autumnal, as, of course, we move from meteorological summer into
39:46meteorological autumn.
39:48It's going to take a lot of rain to make up for the current situation,
39:51but what we've got at the moment, and what may occur next week, will be a good start.
39:57We'll keep our data right here in the Met Office, of course.
39:59And, yeah, don't forget to follow us, and subscribe, and hit like, and comment, and all that jazz.
40:06And stay tuned for the 10-day trend tomorrow on our YouTube channel.
40:09Bye-bye.
Comments