10 Day Trend 20/11/2024 – Further snow and ice - video Dailymotion

Met Office

This is the Met Office UK Weather forecast for the next 10 days 20/11/2024.   The cold spell will be ending but it won’t be a simple change and before the milder air arrives there’ll be more snow and ice.  Bringing you this 10 day weather outlook is Alex Deakin.

Transcript

00:00We start this 10-day trend in the midst of a wintry week. Much of next week looks more

00:06typically autumnal. The transition, though, could be quite interesting and we have weather

00:11warnings in place. Snow and ice warnings for the next few days, but that's then accompanied

00:16by rain warnings as we go into the weekend. This is the 10-day trend. I'm not going to

00:20go into the full detail of all of those weather warnings. Check out our website or our app

00:25for more details. Here's the bigger picture then with the jet stream, that fast-moving

00:30ribbon of air high up in the atmosphere diving to the south of the UK, meaning that we are

00:34on the cold side of the jet, which is why it has been so chilly. As we go through the

00:39next couple of days, we see a few ripples and wiggles on the jet stream, which are quite

00:44important. And by the time we get to Sunday, we've seen a switch from here to here, a 90-degree

00:51flip in the jet stream, and that has allowed much milder air to spread across the UK. So,

00:56yes, it is going to turn milder by the time we get to Saturday and Sunday. But before

01:02then, as I said, these ripples in the jet stream are going to generate areas of low

01:05pressure, one just scooting to the south on Wednesday night and Thursday. And then we're

01:10out in the Atlantic. It's a bit of a mess with one arm of the jet stream driving south

01:15and trying to develop this area of low pressure. Behind me, another arm of the jet coming out

01:20from North America and picking up these areas of low pressure. But it's actually this one

01:25that looks fairly innocuous, going to kind of merge with the one to the north. And this

01:29part of the jet stream is going to intensify this low. It's developing what we call a right

01:35entrance area to the jet. And look at it suddenly become quite a vicious area of low pressure

01:40by the time we get to Sunday. Now, the jet's going to push it up to the north of the UK.

01:44But these weather fronts swinging across the country from this low will bring wet weather

01:48and with the isobars that closely packed, it's also going to bring some windy weather.

01:54More on that low in a moment. But first of all, let's deal with this one just scooting

01:58to the southwest through Wednesday night and Thursday, pushed along by the jet stream again.

02:03Just how intense it is will determine the exact flavour of the weather that we see across

02:09the southwestern quarter of the UK as it moves to the south. The winds coming up from the

02:13south will introduce some milder air. Much of the UK will start with a frost on Thursday

02:20morning towns and cities down below freezing. But that milder air coming into the southwest

02:24means temperatures here a little bit above. But it's going to be a miss, a messy mixture

02:30of rain, sleet and snow that we see from that low pressure because we're on the cusp of

02:34those temperatures. A subtle change, bringing slightly cooler conditions or slightly milder

02:39air from the sea will have big impact. So, yes, giving us a few headaches, this area

02:44of wet weather, we are likely to see some snow Wednesday night into Thursday, particularly

02:49over the moors, several centimetres. But there is the possibility, depending on local conditions

02:54and the exact temperature, that we could see some snow even getting down to lower levels

02:59for a time. Then there's this other zone of wintry weather coming south during Thursday

03:05night and into Friday for Northern Ireland, Northern England, parts of the Midlands and

03:09Wales. Again, that could have some snow mixed in. Again, most of it likely over the hills,

03:12but we could even see a covering at low levels and certainly likely to generate some icy

03:17conditions. And for the next 48 hours, with the winds coming in from the north, that's

03:22just going to pepper Northern Scotland with more snow showers likely here. They may start

03:27to fade a little bit on Friday and by then slightly milder air is coming into many western

03:32areas. So, the showers that we see on Friday, although initially could have some sleet and

03:36snow, by the afternoon will chiefly be of rain. And for much of southern Scotland, eastern

03:41England, southern England, a good chunk of south Wales, actually a fine sunny day on

03:46Friday. Still pretty cold in the east, four or five degrees, but temperatures are starting

03:50to rise down across the southwest. Further southwest still, if I just shift out of the

03:55way, that zone of wet weather there, that is tied into that low pressure we saw at the

04:00start. There it is, pushing its way up between the UK and Iceland, but really intensifying

04:06the ice about jumping out of it as we go through the weekend, generating some pretty

04:11gusty winds, particularly so for the Republic of Ireland, it looks like later on Sunday.

04:15So, that's something we need to watch. But as well as generating some wet and windy weather,

04:21it is coming in from the Atlantic. So, it's also bringing in some milder air, the cold

04:26air in place until Friday night. And here comes that weather system just shunting away

04:31the colder air. But it's also bringing in the moisture. And as the moisture from these

04:36weather fronts hits the cold air, well, yes, we are likely to see at least some snowfall.

04:43Again, elevation, how high up you are, will really count. But we could see some heavy

04:49snow as it moves its way northwards over the hills of northern England and into Scotland.

04:53But even at lower levels, it could be a short blast of snow and it could dump quite a bit,

04:57say, with the Vale of York, even at lower levels across parts of Scotland. So, that's

05:01another thing we need to watch. We also need to watch the rainfall totals building up.

05:06In the south of the milder air, it will be rain that we see. But just highlighting here,

05:10these are the 24-hour rainfall accumulations, particularly the hills of South Wales and

05:15southwest England, seeing some quite heavy bursts of rain. And that could cause some

05:20problems as the rainfall builds up over the course of Saturday in particular.

05:25These are the main three computer model projections, all showing the same thing, really, all just

05:29highlighting that zone across South Wales. Met Office model behind me, ECMWF, the European

05:34model here, and GFS, the American model. The more coarser models, not really picking out

05:40too much detail, but just highlights there over 100mm across parts of South Wales. That

05:45is pretty significant, that rainfall building up. And the even higher resolution UK Met

05:50Office model, really picking out the hills of South Wales there, maybe as much as 150mm.

05:56And quite widely in this zone over South Wales, southwest England, we could see 50-75mm

06:01of rain. Now, it has been quite a dry start to November, but October was pretty wet. And

06:06these kind of rainfall totals falling in 24 hours could cause some further disruptions.

06:12So there are warnings in place for the rainfall. Here comes that snow in slightly more detail.

06:17You see the colder air in place again for much of the country on Saturday morning. And

06:21then that tracks its way slowly northward so that by Saturday afternoon, it's mostly

06:25rain that we're seeing across the country. But as that wet weather moves north on Saturday

06:29morning, parts of the Trans-Pennine routes in particular and then into parts of Scotland

06:34could see a spell of snowy weather and accompanied by gusty winds as well, snowfall and strong

06:41winds. That means blizzards. So some pretty unpleasant travelling conditions on Saturday.

06:45So if you have got plans travelling-wise on the roads on Saturday, just bear that in mind

06:50and do keep up to date with the forecast. Low pressure generating that wintry weather

06:57then through the course of the weekend sits around up to the northwest of the UK for Sunday

07:01and Monday, generating more showers. But also as it starts to cross, the cooler air just

07:08pulls back in down to the south of it. So yes, it turns quite a bit milder for Saturday.

07:13But then through Sunday and Monday, it starts to turn cooler once more with plenty more

07:18showers. Most of those showers will be of rain. What about after that? Well, actually

07:23quite a strong signal here that low pressure dominates through the rest of this week into

07:27the weekend. But then we see a switch around into next week with the reds here indicating

07:31high pressure. That's the dates going forward. This is the multi-model most likely pressure

07:37regime. Previous computer model runs down the side. Blue is low pressure. Red is high

07:42pressure and quite a strong signal there that we will flip over. But of course, not all

07:46high pressures are the same. This just indicating pressure higher than average doesn't mean

07:51we're going to have a high pressure sitting right over us. And when you break it down

07:54a little bit more and look at some of the regimes, the different types of flavour of

08:00high pressure that we could see, the most likely one, this mid-reddy orange colour here

08:05is actually for Scandinavian high pressure to dominate. That's where high pressure is

08:08actually sitting over Scandinavia. Now, that can still bring the UK some dry weather, but

08:14it can, in some instances, also generate easterly winds. Actually, what's more likely

08:20is that the high is a little further south. The European model suggesting this is the

08:26most likely weather flavour for the second half of next week, with the high pressure

08:30sitting just to the south, low pressure systems sitting down to the west of the southwest.

08:35Some of these lows in some of the models do whiz across parts of the south. So that's

08:39something we need to keep an eye on. But in this kind of setup, with the winds going clockwise

08:44around high pressure and anti-clockwise around low pressure, that would generate more southerly

08:48winds. And that would actually generate something a little bit milder. So, plenty going on in

08:53the short term. What do we know about next week? Well, we are likely to see things calming

08:58down at least somewhat. A colder start after things turn milder through the weekend, then

09:04turning milder again through the second half of the week, remaining changeable. So, yes,

09:09with the potential for low pressures to move in across the south, that could bring further

09:12spells of wet weather. But generally, higher pressure nearby, and that would indicate less

09:19lively, less turbulent weather than we are seeing this week. Do please keep up to date

09:25with all of the Met Office weather warnings through our app, through our website. And

09:29if you haven't done already, subscribe to our YouTube channel.

10 Day Trend 20/11/2024 – Further snow and ice

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