- 2 years ago
This is an in-depth Met Office UK Weather forecast for the next week and beyond.
What caused the exceptional rain during the past week? And how much further rain will this week bring? 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.
What caused the exceptional rain during the past week? And how much further rain will this week bring? 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 Last week was a powerful reminder of just how destructive the weather can be, from the
00:05 homes and businesses that were destroyed to the lives that were tragically lost.
00:12 What caused Storm Barbet?
00:15 Why did we see such exceptionally high amounts of rainfall in some parts of the UK?
00:21 And are we expecting a change in the weather this week, or will we see further rain in
00:27 those areas worst hit by Storm Barbet?
00:30 I'm going to be trying to answer all of those questions in this week's deep dive, but before
00:34 I do so, let's just take a look back at the rainfall radar over the last five days and
00:39 you'll just see how relentless that rain was.
00:41 It set in early Thursday.
00:43 This rainfall radar sequence starts at 2pm on Thursday, but let's play it forward.
00:48 It set in across eastern Scotland there.
00:49 Those bright colours across Angus and Aberdeenshire in particular, parts of Caithness, really
00:53 you can see how they persisted overnight.
00:55 The heaviest of the rain occurred on Thursday night into the start of Friday, but it was
00:59 still wet through Friday.
01:00 The rain eventually easing off.
01:01 However, elsewhere across the UK we saw this pulse of very heavy rain into East Anglia,
01:06 the Midlands, parts of Northern England, North Wales in particular, and flooding in these
01:09 areas as well.
01:11 But then the rain returned across eastern Scotland, northern Scotland on Saturday, exacerbating
01:18 the impacts and not helping the recovery effort.
01:22 Finally, through Sunday it turned drier across many parts of the UK, still some showers feeding
01:27 into the west, but it has been a drier interlude over the last couple of days.
01:32 A little breather, but we can just about show you here how much rainfall added up during
01:40 Wednesday to Saturday last week.
01:44 And you can see some really exceptional amounts of rain there on the map, everywhere from
01:48 Northern Ireland to eastern Scotland, eastern and central parts of England.
01:53 And the highest totals really across some of these eastern hills, so east-facing parts
01:59 of the Peak District and the Pennines, 149mm there, Redmire's reservoir, and 203mm for
02:06 Waterside Perth.
02:07 Now, it may be that some eastern hills of Angus and Aberdeenshire saw even higher totals
02:15 and weren't sampled by a rain gauge, but nevertheless, more than 200mm of rain in a matter of days,
02:23 that exceeds the average October rainfall in just a few days.
02:26 So little surprise that it led to such devastating impacts.
02:31 So what caused all of that rain last week and what's changed this week?
02:37 Well, the main thing that caused it was the fact that we had an area of high pressure
02:46 situated across northern parts of Scandinavia, a blocking area of high pressure, and then
02:53 we had this powerful jet stream that was running along the Atlantic there, real power in that
03:01 jet stream, which helped to form areas of low pressure.
03:07 And one in particular, Storm Barbet, moved up from the southwest and then became parked
03:18 just about here, with the wind circulating anti-clockwise around areas of low pressure.
03:29 And as that low pressure moved up against the blocking area of high pressure, the isobars
03:33 squeezed together and we had this strong wind, this gale force wind from the east-southeast.
03:40 In fact, gusts of 60, 70 and I think the peak gust was 77mph affected eastern parts of Scotland.
03:48 And this low, Storm Barbet, picked up an awful lot of moisture on its journey from the southwest,
03:54 from the Bay of Biscay up towards the UK.
03:57 So it had a lot of moisture and we had this strong, persistent east-southeasterly for
04:03 days on end.
04:06 And as a result, that's an unusual direction for the UK.
04:09 We normally get our weather from the west.
04:11 Normally it's western parts of the UK that see the highest rainfall totals, but in this
04:16 instance, it was the easterly winds that brought very high rainfall totals to eastern parts
04:20 of Scotland.
04:21 And so in a region that, yeah, gets a fair amount of rain in October, we got an exceptional
04:26 amount of rain in just a few days.
04:30 And it was that high pressure over Scandinavia that led to the low squeezing up against it
04:35 and this persistent east-southeasterly wind.
04:40 So what's changed this week?
04:42 Not much, but some subtle changes have occurred in the atmosphere which will help the situation
04:48 this week.
04:50 We've still got a powerful jet stream running across the Atlantic, as you can see.
04:55 We've still got high pressure over Scandinavia, but if we skip it forward, there's the high,
05:00 if we skip it forward, say, 24 hours, what you can see is that high pressure is just
05:05 a bit further east.
05:06 So last week it was around about here, just a bit further east.
05:10 We've still got low pressure forming along this powerful jet stream, as is typical in
05:15 October, but these lows are not squeezing so much against the high pressure.
05:21 They're not leading to such strong winds coming in from the east-southeast, but there are
05:26 still weather fronts coming up against parts of eastern Scotland and north-east England
05:30 this week.
05:31 There's still a bit of an easterly airflow and there's still further rain to come through
05:36 the week.
05:37 However, these lows aren't picking up quite as much moisture and the winds aren't quite
05:41 as strong.
05:42 So that helped limit rainfall totals, and I'm going to show the rainfall totals through
05:46 the next six days or so across the UK in just a moment, but those factors will help to limit
05:53 the rainfall totals during the rest of this week.
05:56 It'll be a notch down compared with last week, both in terms of wind speed and rainfall totals.
06:01 So let's just play this forward.
06:02 This is the start of Wednesday, and what you can see, it's a whistle-stop tour for the
06:10 UK's weather this week.
06:11 We've got areas of low pressure moving in on this jet stream, but on the whole, low
06:18 pressure is sitting out towards the west of the UK.
06:20 That's the main theme this week.
06:22 Low pressure sitting to the west of the UK.
06:24 Some lows will form across eastern parts of England into the North Sea, but all in all,
06:31 the main low is just sitting there to the west of the UK.
06:34 And what that leads to for many parts of the country is what we call a returning polar
06:39 maritime air mass.
06:41 There's a number of air masses that affect the UK, and they're called names depending
06:48 on whether they come from a continental or a maritime direction, or whether they come
06:53 from a polar direction or a tropical direction, and so on.
06:58 Now a returning polar maritime air mass, that, if we just take polar maritime, that would
07:04 be a polar direction from the northwest, typically, so coming out of Canada or Greenland and coming
07:10 over the sea.
07:11 That's the Atlantic.
07:12 They're typically air masses that are cool or cold and unstable, so lots of showers.
07:19 Now a returning polar maritime is slightly different.
07:24 It does originate from the poles, but it comes south, overshoots the UK, and then comes north
07:31 again.
07:32 So typically, when you've got a low pressure sitting to the west of the UK, it comes in,
07:36 it dips south, and then returns north.
07:38 So they tend to pick up a bit more moisture and a bit more instability as they move over
07:43 the warmer seas to the southwest of the UK.
07:46 So what you can expect with a returning polar maritime air mass, which is what we're going
07:50 to see Wednesday through to Saturday or Sunday, is lots of showers across the UK, particularly
07:57 towards southwestern areas.
07:59 The areas that are mostly affected by these showers.
08:03 And relatively mild, although not exceptionally mild.
08:07 Now that's the main theme this week, this returning polar maritime airflow.
08:13 But for eastern Scotland and northeast England, what you can see is weather fronts lingering
08:19 and still a bit of an easterly feed from Thursday to Friday and into the weekend.
08:25 We've got this easterly feed feeding moisture in from the North Sea.
08:28 Not as much moisture as we saw last week, but still some moisture nevertheless.
08:33 And I'm just going to show you some rainfall totals in a moment, but there's a common theme
08:38 here for most of the UK.
08:40 It's returning polar maritime, it's heavy showers, some thunderstorms as well coming
08:44 up from the southwest.
08:45 And then later on, so into Saturday night and Sunday, another low replaces that initial
08:51 low to the west and develops and comes up from the southwest.
08:56 So these lows are coming in from the west and southwest, often bringing showers or sometimes
09:01 longer spells of rain and blustery winds to the south and southwest.
09:05 But this other common theme, eastern Scotland, northeast England, seeing a feed of more persistent
09:11 rain at times through the week.
09:14 So let's just play that forward and you'll see again a little whistle stop tour of the
09:19 UK weather for this week.
09:21 For the rest of Tuesday, we've got some persistent bands of rain across northern England into
09:25 southern Scotland, showers feeding in across southwestern areas, but skipping forward to
09:30 the start of Wednesday.
09:32 And clear skies overnight will lead to some fog patches in places, northern Ireland into
09:35 parts of Wales, north England, East Anglia, for example.
09:40 But there are two areas rain at first on Wednesday.
09:43 There's this area that is a little frontal feature that runs along the south of England
09:47 and south Wales overnight.
09:49 And that does clear through the morning.
09:52 So that does wet morning, yeah, but that does push away to the southeast.
09:57 Then we've got this other persistent easterly flow setting in across eastern Scotland, parts
10:02 of northeast England.
10:03 So cloudy, damp, but nothing particularly large in terms of rainfall accumulations through
10:11 Wednesday.
10:12 Elsewhere, after the early mist and fog cliffs, actually Wales, the Midlands, northern Ireland,
10:17 southwest England seeing plenty of fine and bright weather.
10:20 But at this stage, a weather front starting to feed into the southwest of England.
10:27 By 4pm or so, you've got the wind picking up and Cornwall turning a little wet.
10:33 Again, we've got that rain continuing in eastern Scotland, but the showery rain towards the
10:37 southeast by the end of the afternoon is pushing away.
10:40 So a drier interlude, a six to nine hour period of mainly dry conditions.
10:45 Western Scotland, sunny spells, mostly dry here because of the easterly airflow.
10:50 And then skipping forward to Thursday, again a few mist and fog patches possible where
10:55 we've got clear spells overnight.
10:57 But the rain that moves into the southwest, that's tracking across the country so that
11:03 by early Thursday it's into the southeast as well as the east Midlands, east Anglia
11:08 and pushing out towards northwest England and northern Ireland.
11:12 Now playing that forward, I'm just going to pause it there.
11:17 And what you can see is some heavier pulses developing on that rain in the east of England
11:23 as a small area of low pressure potentially forms along that.
11:27 And that's one watch point over the next few days.
11:29 I'm going to talk a bit more about the uncertainties involved with that area of rainfall in just
11:34 a moment.
11:35 But elsewhere, we've got continued rain or showers across eastern and southern Scotland.
11:40 Northern Ireland seeing a few showers by the afternoon.
11:42 Wales and the southwest seeing some heavy showers.
11:44 This is that returning polar maritime airflow setting in.
11:46 So we've got a southwesterly feed and we've got some heavy downpours interspersed by sunny
11:51 spells and fairly mild.
11:54 But yeah, plenty of showers and quite lively showers at that with gusty winds.
12:00 Now into, when's this, Thursday night, we've got the rain or showers continuing across
12:06 eastern Scotland, northeast England.
12:08 Further showers feeding into the south and southwest parts of northern Ireland and Wales.
12:15 And really this is how it looks on Friday.
12:20 Rain or showers across eastern Scotland.
12:23 Plenty of showers for northern Ireland and Wales, the south and southwest of England.
12:26 That's that returning polar maritime air mass that we've got through the next few days.
12:30 In between, a lot of fine weather.
12:32 Western Scotland again, the place to be for dry and bright weather.
12:36 Northwest England also faring well as well as east Anglia, a gap there after a potentially
12:42 wet day on Thursday.
12:45 Further showers feeding around the whole of the UK on Friday night.
12:50 And the showers increasingly blustery, quite strong winds coming in to the southwest as
12:55 that next low starts to appear.
12:57 And that really makes an appearance on Saturday night.
13:00 So this is going into Saturday afternoon.
13:02 And what you'll see is this increase in rainfall coming along into the south and southwest.
13:06 Obviously this is five or six days ahead.
13:09 So some uncertainty about the track of this low, but it could be that on Saturday night
13:13 it turns increasingly wet and windy in the south.
13:16 Again, we've got this persistent feed of rain into the east of Scotland.
13:20 So essentially there are a number of features that are persisting through the next few days
13:26 until the end of the weekend.
13:27 We've got those heavy downpours, the lively showers across many parts of the south and
13:32 the west.
13:33 That's the returning polar maritime air mass.
13:36 And then eastern Scotland, northeast England often seeing outbreaks of rain waxing and
13:40 waning through the rest of the week and into the weekend, but some rain building up.
13:45 So if we run that through as a animation, building up the rain over time and represent
13:53 it as 3D bars, what you can see is that initially through Wednesday and into Thursday, these
13:58 bars starting to rise out of the map across the south and southwest and elsewhere across
14:04 the UK, quite a bit of rainfall.
14:07 But western Scotland, western parts of Northern Ireland, northwest England actually avoiding
14:12 much of this.
14:14 And then later in the week, a pulse of heavier rain increasing the size of those bars and
14:21 the colours indicating that we could see 100mm plus across parts of Aberdeenshire in particular.
14:26 And actually as the map zooms out there, you can see the focus there just to the west of
14:31 Aberdeenshire.
14:32 Not in exactly the same place as we saw the highest rainfall totals last week, although
14:36 there's some uncertainties about this.
14:39 And also another area, just a slice along the coast there of south-east England seeing
14:46 some significant rainfall totals as well, because there's a couple of bands expected
14:51 to go through over the next few days.
14:53 So largest rainfall totals through the rest of the weekend and the weekend, the south
14:57 and the southwest of the UK, but also eastern parts of Scotland.
15:01 And playing that through once again, you can see how it's Thursday night into Friday, those
15:05 totals really start to add up.
15:07 And then into the weekend as well, another pulse of rain with 100mm or more over some
15:12 of the higher parts, the east-facing hills of Aberdeenshire, perhaps Angus as well.
15:17 Hopefully not exacerbating things too much, but any additional rainfall obviously over
15:23 the next few days is not going to be at all welcome.
15:26 But this is around half the amount of rain that we saw last week and spread over a slightly
15:33 longer period of time.
15:36 So that's one way of visualising the rainfall totals over the next few days.
15:41 Another interesting way I thought you might like are these confetti plots.
15:45 Now this is the UK here, and this shows midday tomorrow, midday Wednesday at the time of
15:52 recording, it's tomorrow.
15:53 And if you imagine you take each of these colours, say a red colour or a blue colour,
16:00 that represents one model run from the Met Office Ensemble Suite, and there are 34 runs,
16:08 OK?
16:09 And each colour represents the rain position at midday on Wednesday.
16:15 So what we've got here are 34 different colours showing 34 different representations of the
16:21 rain position.
16:22 And this is really handy, these are called confetti plots for obvious reasons, it's really
16:28 handy for looking at the location of where we're going to get the showers and also where
16:32 we're likely to see dry weather.
16:34 So where you've got no confetti, it's most likely to be dry because none of the computer
16:39 model runs, none of these 34 runs are showing rain across say most of Wales, Northern England,
16:46 Western Scotland, Northern Ireland at this time on Wednesday.
16:50 There's lots of different colours here to the southwest, that's that band of rain that's
16:53 moving in later Wednesday, but some uncertainty about how far into the southwest that appears,
17:00 hence the different colours.
17:01 Likewise, the showers that are clearing East Anglia and the southeast as well as eastern
17:05 Scotland are represented by different colours, but actually most of the UK, as this shows,
17:12 dry at midday Wednesday.
17:14 So we've got the showers clearing from the east, we've got the rain appearing in the
17:16 southwest, in between none of these confetti colours across the map.
17:22 Conversely, skipping ahead to Friday, a very showery day for most of us, and this shows
17:28 you might not be able to see the UK very clearly under all of the confetti, but here's Scotland
17:32 in the north here, there's East Anglia, there's southwest England, and as you can see, lots
17:37 of confetti across Northern Ireland, southwest Scotland, Wales and the southwest.
17:41 That just indicates, as well as the south, the far southeast, that just indicates that
17:46 there's likely to be some showers.
17:48 The different colours represent different model runs.
17:52 They disagree about exactly where and when we'll see the showers on Friday, but certainly
17:57 there's that chance across the south and the west.
18:00 Conversely, East Anglia, we've got no colours.
18:03 Western Scotland, mostly clear of it.
18:06 So that just indicates there that by Friday, after the spell of rain potentially goes through
18:12 on Thursday, East Anglia and the west of Scotland mostly dry.
18:17 Western Scotland, meanwhile, seeing quite a few of these colours, so that persistent
18:21 rain.
18:22 Now, I also mentioned that there's the potential for low pressure to pep up the rain on Thursday
18:29 in the east of England.
18:31 One way of showing that is this.
18:33 Again, it takes all the different computer model runs from the Met Office model and it
18:40 plots the low pressure centre from each of these model runs as a colour.
18:45 The colour represents the depth of the low.
18:47 So the main low is going to be sitting out to the west of the UK, and this is Thursday,
18:52 by the way, at midday.
18:54 And we've got the main low sitting to the west and typically these colours represent
18:59 975, 980 millibars, hectopascals.
19:04 Then there's a few of the computer model runs that are picking up another low just off the
19:10 East Anglia coast there.
19:12 And it's a less deep low, but showing generally 990, 995 hectopascals, but not all of the
19:20 models are picking up that low.
19:23 And this just shows you a sample.
19:25 This is from one model that isn't picking up the low.
19:29 We've got the main low there to the west, no low there to the east, and then another
19:34 one that does pick out the low.
19:37 Main low there to the west, one low there.
19:41 And if that happens, if we get this circulation forming on Thursday as the rain clears the
19:47 east of England, then it will just pep up the rain.
19:49 It will make it last a bit longer in the east of England.
19:52 And it looks fairly likely, given a number of computer model runs that are suggesting
19:59 a low now, that a little shallow low will form off East Anglia, enough to pep up the
20:05 rain for a time before that clears and then on Friday, as you saw, it's mostly dry across
20:10 East Anglia and the East Midlands.
20:14 But yeah, that's just another interesting aspect of the forecast I thought I'd bring
20:18 out.
20:19 Oh, by the way, while we're on this, this is the total rainfall so far this October
20:26 up till yesterday, up till the 23rd.
20:30 And the blues show where the rainfall so far this month has exceeded the October average.
20:35 You can see quite a large swathe across the Midlands into the east of England, northeast
20:39 England there and eastern Scotland.
20:41 And some of these darker blues indicate more than twice the October rainfall so far this
20:46 month.
20:47 But there's some browns as well.
20:48 So rainfall has been highly variable.
20:50 The brown areas indicating where we've seen less than the October rainfall.
20:54 At this point in the month, you'd typically expect around 68, which is this shade of brown.
20:58 Some areas have had a drier than average October so far, mainly southwest Scotland, Cornwall.
21:04 That's quite interesting as well.
21:06 Where are we?
21:07 Have we covered everything?
21:08 Thursday's low, a bit of fog tonight.
21:10 I think I mentioned that in some central parts.
21:14 And finally, how long will the unsettled weather last?
21:18 I know that's what a lot of people have been crying out for.
21:22 A bit of a change in things after last week's terrible weather.
21:27 And this shows the most likely weather pattern for the last day of October, so for Halloween.
21:34 And the main indications are that through the weekend, we've got that next low coming
21:38 up to bring some wet and windy weather potentially to the south of the UK for a time before that
21:42 clears away.
21:43 And as that clears away, the start of next week, it pushes into Scandinavia.
21:48 There are some indications that we'll get a colder, but generally drier, air feed from
21:54 the north.
21:56 And that that might just be a temporary thing because then there are signs that low pressure
22:02 will return.
22:04 Looking further ahead into November, things at the moment are fairly finely balanced between
22:11 the blocking high returning to Scandinavia and having an influence on the UK and further
22:17 lows coming in from the west.
22:19 And as explained in previous deep dives and 10-day trend and so on, we've got El Niño
22:24 at the moment in the Pacific.
22:26 And that tends to help unsettled weather affect the UK in October and November.
22:35 So on balance, if the computer models are finely balanced between high pressure and
22:40 low pressure, but we've got this El Niño happening, you would slightly favour the low
22:45 pressure, the unsettled weather continuing.
22:48 So further spells of rain and wind and mild for the time of year.
22:53 But a lot of uncertainty at the moment when you look into November.
22:57 So I'm sure we'll cover that more in the next few days and weeks.
23:01 Alex Burka will be covering the 10-day trend tomorrow.
23:03 Make sure you don't miss that.
23:04 And he'll have more on the longer range.
23:07 But for now, thank you for joining me.
23:09 If you enjoy these deep dives, please don't forget to hit subscribe so you don't miss
23:13 one in the future.
23:15 And it'll help us justify doing more of these in the future as well.
23:19 Bye bye.
Recommended
1:17:45
2:38
6:45
Be the first to comment