- 3 minutes ago
This is an in-depth Met Office UK Weather forecast for the next week and beyond.
Something unusual is happening high above the Arctic. The stratospheric polar vortex has weakened and become dramatically stretched, with powerful planetary waves travelling upwards from the lower atmosphere and disturbing the vortex.
In this Deep Dive, we explain what the stratospheric polar vortex is, what happens during a sudden stratospheric warming (SSW), and the difference between Wave 1 and Wave 2 disturbances. We look at why the current Wave 2 pattern has deformed the vortex, whether forecasts suggest the winds could reverse and produce a major SSW, and why that still wouldn't guarantee cold weather for the UK.
Something unusual is happening high above the Arctic. The stratospheric polar vortex has weakened and become dramatically stretched, with powerful planetary waves travelling upwards from the lower atmosphere and disturbing the vortex.
In this Deep Dive, we explain what the stratospheric polar vortex is, what happens during a sudden stratospheric warming (SSW), and the difference between Wave 1 and Wave 2 disturbances. We look at why the current Wave 2 pattern has deformed the vortex, whether forecasts suggest the winds could reverse and produce a major SSW, and why that still wouldn't guarantee cold weather for the UK.
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NewsTranscript
00:00The stratospheric polar vortex above the North Pole is currently being disturbed and this could lead
00:05to a major sudden stratospheric warming, which could lead to relatively cold and
00:12relatively dry weather for the UK in a few weeks. And all of this could be caused by the current
00:22record-breaking El Nino. Welcome to the Met Office Deep Dive. Thank you for joining me. We do these
00:27regular in-depth discussions of the weather across the UK and around the world, as well as the reasons
00:33behind that weather every Tuesday on our YouTube channel and elsewhere, for example, Spotify. If
00:40you like these in-depth analyses, please don't forget to hit subscribe. Tell your friends about
00:46this kind of thing if you think they'll enjoy it. Send us a like, send us a question. We try
00:51and
00:51answer your questions in the Weather Studio Live on a Friday. Now, in my introduction, I mentioned
00:57could a few times. And if you're the kind of person who hears probabilistic terms such as could or may
01:03in a forecast like this and then is compelled to comment something like, so they don't have a clue,
01:10then this might not be the forecast for you. We do plenty of other forecasts on our YouTube channel
01:15covering the weather over the next couple of days. Probabilistic terms aren't used as frequently
01:21because we have a greater idea, greater confidence about what's going on. But when we're talking about
01:25the weather beyond a week or two, we inevitably have to use terms such as could or may or there's
01:32a certain percentage chance of this or that because that's how weather forecasting in the modern world
01:39works. Don't be fooled by people online or headlines that indicate that we know for certain what the
01:48weather is going to bring in a month or two months or at the end of winter or whatever. That
01:53simply isn't
01:54the case. We have to use terms of probability. So like I say, if you find probability difficult or
02:00don't enjoy watching forecasts where terms of probability are used, this may not be the forecast
02:06for you. In fact, this isn't going to be much of a forecast. There's not much I'm going to say
02:11about
02:11the forecast. All I'm interested in or what I'm mainly interested in exploring this week is why
02:19there's a connection between El Nino, sudden stratospheric warmings and potentially colder
02:26weather reaching the UK. The chain of events that starts off in the tropical Pacific and ends up
02:32with northerly or easterly winds for the UK or blocking high over the UK or different weather
02:40patterns compared with what we typically expect in the autumn and the winter. So I'm going to be
02:46focusing on that chain of events this week because if you're anything like me, when you hear forecasts
02:53or meteorologists say that because of El Nino there's a greater chance of cold weather at the end of
02:59winter, you might immediately think, why? Why is that? So hopefully in the next 20-30 minutes or so
03:07I'm going to answer those questions. I'm going to talk about the connection between El Nino and the UK's
03:13weather. But first of all, let's start off with sudden stratospheric warmings. We've covered them
03:20plenty on our YouTube channel. There are longer explainers than the one I'm going to do here.
03:25This is just a recap, a quick summary for those who are less familiar with what a sudden stratospheric
03:31warming is and how it affects the UK's weather. Let's start off with the North Pole. There it is.
03:37There's Greenland. UK over there. And there's North America. Here's Russia and so on.
03:44Got my crayon ready. I'm going to draw some lines on the map and show you what typically happens with
03:49the stratospheric polar vortex through the autumn and into the winter. Now, during the autumn, the
03:56northern hemisphere starts tilting away from the sun. So we get cold air increasingly above the
04:03North Pole or increasingly cold air, very cold air in the stratosphere above the North Pole because it's
04:10in the stratosphere that we get heating directly from the sun. You don't actually get that in the
04:16troposphere. The troposphere is heated by the ground, the troposphere being the lowest layer of the
04:20atmosphere where we live, where our weather occurs. The troposphere is heated from the ground. The ground is
04:26heated by the sun. But funny enough, the stratosphere is heated directly by the sun during the summer when
04:32the North Pole points towards the sun. The stratosphere above the North Pole is warmed up by the sun
04:38because of the ozone in the stratosphere. So you get warmer air in the stratosphere relative to winter
04:44above the North Pole in the summer. Now, in the winter, the North Pole points away. So the stratosphere
04:50no longer gets that sunlight, no longer gets that warming. You get colder air forming. Meanwhile, it's very warm
04:56still in the stratosphere above the equator. So the temperature difference between the equator and the
05:02North Pole in the stratosphere is enhanced. And when you get a greater temperature gradient, you get an enhancement
05:08of the westerly winds. Now, without the Coriolis effect, without the Earth spinning, it would be more of a direct
05:14wind
05:14from the equator to the pole to even out that temperature difference. But because the Earth's spinning, it's a westerly
05:20wind,
05:20similar to the cause of our own westerlies in the troposphere, the jet stream, and so on. So what you
05:26get, here it is,
05:28this ring of very strong winds surrounding the North Pole in the stratosphere in a westerly direction,
05:37forming and strengthening through the autumn and continuing to strengthen, reaching a peak around January
05:45every winter, every winter, on average. Now, there's that ring, and what you'll notice is it's relatively
05:52circular, compared with what we get in the troposphere, or towards the top of the troposphere, near the
05:59tropopause, with our very own jet stream, which similarly tends to go in a westerly direction, but it's much
06:11more wriggly, so it's something like that. It's less circular, and those wriggles vary day-to-day, week-to-week,
06:21season-to-season. These are called waves, for obvious reasons. Oh, there it is. Let's come back again.
06:29These are called waves, and again, going in a westerly direction, but it's much more wriggly, sometimes more than others.
06:36The reason you get these waves forming, they're called Rossby waves, by the way, the reason you get these waves
06:42forming is because the jet stream in the troposphere is much closer to the ground. It's 10 kilometers above sea
06:50level, rather than 30 kilometers above sea level, where the stratospheric polar vortex may be spinning,
06:57so it's closer to the ground, and more affected by topography. It kind of meanders around mountain regions.
07:04It's affected by the temperature contrast between oceans and land areas. Those temperature contrasts,
07:11the higher ground, all of that sort of thing can lead to its meandering around the planet a lot more.
07:19So the jet stream more wriggly, stratospheric polar vortex more circular on average. But these Rossby waves
07:27are important. And actually, let's draw, let's focus in on this area. On average, you get low pressure
07:36in this region and a dip in the jet stream. Here we go, coming around here. And then it comes
07:44back in
07:44and get a ridge. This is during the winter. You get a ridge over parts of North America, more towards
07:51western parts, for example, or eastern parts, I should say. So that's an average. That's a typical
07:58meander of the jet stream. This is called the Aleutian low, by the way. And when you get these wriggles,
08:05if they become more amplified, it's worth imagining them in three dimensions as well. It's not just wriggling
08:13east to west, north to south on the map, but it's wriggling upwards as well. And you get the air
08:20moving in three dimensions up and then down and so on. So it's a bit like waves in the sea,
08:28up and down,
08:29up and down. And when those waves in the troposphere extend enough, they can break into the stratosphere.
08:37And when you get a wave, one of these bumps in the atmosphere lower down, breaking further up
08:45into the stratosphere, that can put the brakes on the stratospheric polar vortex wind. So it can disturb
08:55it. And there's a couple of different types of disturbance that originate in the troposphere
09:00and extend in the stratosphere. So one type of disturbance is, for example, when you get this
09:06very strong area of high pressure coming up like that. And that's in the troposphere, by the way,
09:12let's say you've got high pressure there, big high coming in like that. And then imagine in this area,
09:20you've got the stratospheric polar vortex coming around in circular fashion. But this high, it's bumping in.
09:30So you get this stratospheric polar vortex being bumped off the pole. So one type of disturbance is known as
09:39a displacement of the stratospheric polar vortex. It's still spinning. It's just not spinning over the north pole anymore.
09:45It's moved away because of a wave, one wave, by the way, coming up from the troposphere. But what happens
09:54if you get two waves coming up from the troposphere in opposite directions, right? You start with your
10:02circular stratospheric polar vortex. You get one wave attacking from there, one planetary wave attacking from
10:10there, squeezing on both sides, so that it ends up, again, one planetary wave attacking there, one there,
10:18and it ends up being squeezed, known as a deformation. Again, that's the wave, one wave coming up from the
10:29troposphere there, one wave coming up from the opposite direction. It can't knock it off because they're both
10:35coming in from opposite sides, so it gets squeezed. This can lead to it splitting in two. So you get
10:40one
10:41there and one there. Or it can just be deformed and that deformation can move it off the pole as
10:47well.
10:47So there's a few ways in which the stratospheric polar vortex can be disturbed from these bumps and these
10:55waves and these undulations in the troposphere downstairs. And that's how the stratospheric polar vortex can
11:05go from a circle above the north pole with cold air here being contained to that cold air being
11:17displaced and suddenly a weakening of these westerly winds and a warming above the north pole in the
11:26stratosphere. Hence the sudden stratospheric warming because it happens quickly when it happens. These westerlies
11:33decrease, the warming happens quickly. Now a minor warning is where warming is where the stratospheric polar
11:40vortex winds decrease and you get a warming but they don't reverse. When the winds decrease so much
11:50that there's a reversal, so now they're going easterly like that, that's known as a major sudden
11:57stratospheric warming. And all of a sudden it's again you've got a ring of winds here. Wrong colour but
12:08we'll roll with it. And instead of low pressure and cold air above the north pole you've got high pressure
12:13and warm air. It's suddenly warmed because the stratospheric polar vortex is somewhere else.
12:19You've got high pressure winds going in an easterly direction. Now when that happens, high pressure,
12:28warm air above the north pole, reversal of the winds, those anomalous wind directions and pressure
12:36values can, don't always, but can propagate downwards so that two to six weeks later it takes some time,
12:44there's a lag effect. After this two to six weeks later there's a response in the troposphere. So the
12:49troposphere caused it in the first place with the wave motion of the the rosby waves and so on and
12:55the
12:55the low pressure and the high pressure in the troposphere. But then equally the stratospheric
13:01polar vortex and its weakening or its reversal can ultimately cause different things to happen in the
13:08troposphere. Notably a weakening of the jet stream and a greater chance of blocking areas of high pressure.
13:15If those blocking areas of high pressure end up over the UK, you can get clear, cold weather, frost,
13:22greater chance of frosty, foggy nights and so on. If high pressure ends up to the north of the UK,
13:27you can end up with a greater chance of the easterly winds. If high pressure ends up just to the
13:32west,
13:32it's northerly winds, that sort of thing. So it does depend on A, if this anomalous pattern
13:40propagates down to the troposphere and B, where any of these anomalous highs and lows end up, where
13:48these blocking highs end up, that then determines what kind of weather the UK gets two to six weeks
13:54after this happens. Which is why it's not guaranteed when this happens that the UK gets colder weather
14:00but it increases the chances as roughly 70% chance of colder weather when this happens two to six
14:09weeks later. Now we're talking about it now because it's already started to happen and it may end up
14:16being a major sudden stratospheric warming, more on that in a moment, by next week. If that happens,
14:23if there's a major sudden stratospheric warming, it will be the earliest on record that a sudden
14:28stratospheric warming, a major sudden stratospheric warming, has happened in the observational record.
14:35So that's remarkable, but also it makes the response for the UK's weather somewhat uncertain
14:40because we're more used to seeing this chain of events take place later in the season when there is
14:47more cold weather around the northern hemisphere. And so yeah, how much cold weather could potentially
14:55affect the UK if all the conditions line up in the right place, we have to wait and see. And
15:01that's why I'm
15:02saying that this isn't a forecast of what we're going to see in the UK,
15:06it's more of an explanation of the chain of events. But having explained the sudden stratospheric warming
15:13and its effect or its potential effects on the UK's weather, you might be asking, what on earth does
15:20El Nino have to do with any of this? Well, let's do a quick overview of what El Nino means.
15:27And again,
15:27we've covered this a few times in recent weeks and months because it is such a hot topic right now,
15:32pardon the pun. But El Nino is a key driver of these waves in the atmosphere and these disturbances.
15:42I'm going to try and explain that now. This is an overview of the sea surface temperature anomalies
15:48across the planet right now. And in this box here is what scientists call the Nino 3.4 region. This
15:56is the key region for monitoring the activity of La Nina or El Nino. When sea surface temperatures in this
16:03box area are anomalously high over a period of several months, then an El Nino is declared
16:11and they certainly have been anomalously high for months now. And the reason they get so warm in
16:18this region is because typically during a neutral year, not El Nino, not La Nina, you get trade winds
16:27pushing warm water from east to west across the Pacific. That warm water gets piled up over Indonesia,
16:36northern Australia, you get thunderstorms developing here as a result. And you get cooler seas around the
16:42east of the Pacific, upwelling off the South American coast and drier weather here, wetter weather here,
16:50good fishing here and so on. That's a neutral year. Now, when El Nino happens, those trade winds
16:56weaken. And as a result, much of this warm water sloshes back into the central Pacific, hence the warming of
17:03this
17:03region, region 3.4, El Nino region. So this has been warming through the last few months and it's
17:11reached unprecedented levels. I'll show you a graph now. This is the actual temperature. It's gone above
17:1730 Celsius on average in that box. And these are the daily values, by the way, exceeding the previous
17:24record, which is the 2015-2016 season. So it's already exceeded that. And it's likely to peak
17:32at some point in November or December. And the Met Office forecast is for it to be about three degrees
17:38above average, which would make it the warmest on record, a remarkable anomaly. It's already for daily
17:46values around that. But we define it in terms of a three-month rolling average. So we'll have to see
17:53what it ends up. But it's already record-breaking. It's already exceptional. Back to this map. What
17:59happens when you get warmer seas here? Of course, the thunder activity isn't confined to here.
18:05It's more central across the Pacific. And when you get an awful lot of thunderstorms happening
18:12in this central part of the Pacific, more than usual, what thunderstorms do is they produce a
18:18lot of condensation. So water from the Pacific comes into the atmosphere, evaporates, but that
18:24then condenses into thunderstorms. And when water condenses, it releases heat. It's the opposite of
18:33when you get out of the shower. Water on your skin evaporates. That takes heat. It needs heat energy.
18:38It takes heat from your skin. That's why you feel colder. When water condenses, it releases heat.
18:44It makes the atmosphere warmer. So the atmosphere in this region is getting very warm. And that
18:52incredible warmth expands the air in that region and sets it like throwing an enormous pebble into
19:00the central Pacific. It sets off this huge ripple effect that expands outwards throughout the whole
19:05of the Pacific. Now, earlier I mentioned the Aleutian low. Let's go onto the actual forecast
19:14map here and move over to the Pacific. You can see a very strong jet stream over the Pacific there.
19:21And you can also see all these lows of Alaska. And this is the Aleutian low. And what El Nino
19:27does,
19:28as a result of that ripple effect, it enhances the Aleutian low, which in turn enhances the high pressure
19:36downstream. And when you get an enhancement, go back to my drawing tool, when you get an enhancement
19:46of the low here. So even deeper low, big, big, big low here, and then a big high over here,
19:57there's a stronger wave effect. So you've got a much bigger wave rippling through the troposphere,
20:05the lowest 10 kilometers or so of the atmosphere. So that's the downstairs region, more energy going on,
20:11which then can disturb things upstairs. So El Nino is basically enhancing the waves that go on in the
20:21troposphere, the the wriggly jet stream and the waves that then propagate upwards into the stratosphere,
20:28knocking and bumping and disturbing that circle of winds around the stratosphere, around the polar stratosphere,
20:36causing it to be displaced, pushed off the pole or deformed or split.
20:45So what is actually happening? This is a chart from last week. This is a a summary of, well,
20:55technically it's the 500 hectare Pascal geopotential anomaly. But let's simplify things and say it's a
21:03summary of where we had high pressure and low pressure, generally speaking, in the atmosphere
21:07during the last week of October. And just to get your bearings, there's the UK, there's Greenland,
21:15there's Alaska. So we're looking down at the pole. There's the North Pole. I hope this all makes sense.
21:20I know that the lines aren't ideal for viewing it on YouTube or on your phone or whatever,
21:26but I didn't make the chart. So the important thing to point out here is that there's a big area
21:31of low
21:31pressure, as you might expect, the elution low here. The coloured areas are where it's anomalously low
21:38or high, blue for low, orange for high. And then the lines correspond to where we've actually got the
21:43lows and the highs. But just to simplify things, we've got the elution low there, this low pressure
21:49off the coast of North America, western parts of North America. So this anomalous low region, even
21:57lower than normal. Then we've got the corresponding high over North America towards the west or central
22:05parts of North America. So we've got this high pushing towards the North Pole. But at the same time,
22:12there's also an anomalously high region coming in from central Europe up through Scandinavia. This bump
22:20here, this high extending into the North Pole. So just see those two highs squeezing together. And this is an
22:28oversimplification, trying to make things relatively easy to understand. But this is the current shape of the
22:40stratosphere polar vortex. So I showed you where the anomalously high and low regions were in the
22:46troposphere last week. Now I'm showing you where the anomalously low and high parts of the stratosphere are
22:54right now. And one thing to immediately point out is that it's not a perfect circle. Look at the yellow
23:01line here. Again, we're looking down at the North Pole. There's the UK, there's Alaska, just to get your
23:07bearings. And this is the yellow line we're interested in. It's not a perfect circle anymore. It's being pinched,
23:14it's being deformed. There are two low pressure centers coming off, two vortices coming off the North Pole. And
23:22directly over the North Pole, we've got red, which is indicating much warmer than normal in the stratosphere.
23:29It's actually the heights, technically speaking, but let's call it warmer than normal because it's a
23:35good proxy for that. So blue, colder than normal, red, warmer than normal over the North Pole. So we're
23:41seeing now this warming over the North Pole as a result of the stratospheric polar vortex no longer
23:48being circular, but deforming into two vortices that are coming off the pole because they're being
23:54squeezed by either side by goings on in the troposphere. Interestingly, this is from polarvortex.earth,
24:04really good tool actually online, just discovered it for all these maps. And I'm going to show you a
24:08load of graphs now, I'll try and keep them simple again, that also come from that site. So if you
24:14want
24:14to delve a little bit deeper after that, great website for loads of information. Here's another map. Now that
24:21one is the current state of the stratospheric polar vortex from the ECMWF model. So that's the latest run,
24:28and that's midday today. This is the forecast for the 11th of November from the ECMWF model. And this shows
24:39the predicted shape of the stratospheric polar vortex on that day, the 11th of November. It's not so deformed,
24:47but what it is, is it's shifted more from the North Pole. Again, you've got a big red area over
24:54the North
24:54Pole. So again, anomalously warm, anomalously high heights is technically what it's showing, but
24:59anomalously warm, anomalously cold in the stratosphere, not at ground level, in the stratosphere over Europe
25:06and over the Pacific there. And then this is the shape of the stratospheric polar vortex. It's
25:13it's centered over, well, Norway, pharaohs, that kind of region, rather than the North Pole, so it's
25:20shifted off the North Pole. Interestingly, look at these blues. They're extending through Europe, across
25:28Asia, and then there's this other blue area in the Pacific, with the red across, say, parts of Canada
25:36and the North Pole. This pattern is very similar to the pattern that was modeled by Innocent and Scaife
25:44in their 2008 paper that looked at how El Niños cause sudden stratospheric warming, or influence sudden
25:53stratospheric warmings, and the consequences for Europe. And it's a slightly different projection here.
25:58So it's a very similar shape, which shows a different projection. UK is here, North America is over here,
26:06but it also shows, from their modeling, anomalously warm air in the stratosphere above the North Pole,
26:14above Northern Canada, and then this cold region, these vortices coming around the Pacific through Asia
26:20and into Europe. So very similar shape. It's just a slightly different orientation. You might need
26:26to squint a little bit and try and figure it out if you press pause or whatever. But yeah, fascinating
26:31how it's a similar thing. And this is a modeled response to El Niño from the stratosphere.
26:39So, and this is really interesting, basically, that we were talking about, or we could see that the
26:47models were indicating that El Niño would happen this autumn and winter at the end of last year.
26:54And we know from research from, you know, for example, Innocent and Scaife, there's lots of other
27:00papers out there as well, we know that El Niños increase the chances, through these chains of events,
27:07of sudden stratospheric warmings happening. And we know that sudden stratospheric warmings increase the
27:15chances of colder weather for the UK. So we've got this chain of events that we can start to flag
27:22well in advance. End of last year, we had something useful to say. Again, it was probability rather than
27:29certainty. But we had something useful to say about the chances of El Niño, and therefore the chances of
27:35sudden stratospheric warming, and therefore the chances of cold spells in the UK this late autumn and winter.
27:42There was something useful we could talk about even a year ahead. And that's where these
27:49teleconnections are useful, not for telling us exactly what the weather will be on the 22nd of
27:53January next year, but for giving us some clues as to the sequence of events that we might expect,
28:01or the increased chances of a sequence of events in an upcoming season.
28:06So what's going on right now? I showed you there that the stratospheric polar vortex is being deformed
28:13at the moment, it's being stretched. This shows why. Earlier, when I talked about one wave pushing the
28:23stratospheric polar vortex off the pole, and two waves potentially squeezing the two, here's a really useful
28:29graph, again from polar vortex dot earth, which shows the contribution from wave two, that mechanism,
28:37the two wave things. And yeah, there's a lot to get your head around here with the graph, there's a
28:42lot
28:42going on. But basically, these are the months along the bottom, September all the way through to April.
28:48This, the shaded area shows the typical wave two amplitude, let's say, through the season.
28:59When you look at the record in the ECMWF reanalysis from 1959 to 2025, and then the black line is
29:09what
29:10we've actually seen. And you can see the black line goes way ahead, way higher than what you typically
29:17see. And it's forecast to peak on Wednesday the 4th of November. So that essentially means is that we've
29:24seen a much bigger response, a much bigger amplitude to those two waves than you'd see on average from the
29:30record. But it's peaking this Wednesday, according to the forecast. Similarly, I mentioned wave one, and
29:39that hasn't been a big contributor at the moment, but it is rising. Here's the black line again, and the
29:47contribution from wave one, it's rising over the next week or so, forecast again to peak on the 16th
29:54of November. So wave two has been important, the two waves, wave one becoming more important in the
30:01next week or so. What does that mean? Well, it basically means that at the moment, that SPV, the
30:07stratospheric polar vortex is very stretched, that's what we saw. And this shows how stretched the vortex is,
30:13again, the same kind of graph here that shows, on average, the stretchiness of the vortex through the
30:20season. And what we've actually seen, this huge spike, really stretched. And it's forecast, it's almost
30:27three times its stretchiness, if that's the right way to describe it. And it's forecast to peak on
30:35Wednesday the 4th of November. That's how stretched it is. But it's also forecast to become more displaced
30:41from the pole as a result of the contribution, increasing contribution from the wave one aspect
30:46of things. Here is how close it is to the pole. And it's getting further and further away from the
30:52pole, reaching the furthest point, 11th of November. This is the degrees north from the pole. So 90 would
30:59be sitting over the pole. And then it goes down to lower and lower latitudes. And that's the average
31:06range through the season. So to summarize, it's basically very stretched at the moment, then it becomes
31:11less stretched, and it becomes shifted from the pole. That's what we've seen in the model. And finally, this
31:19is the forecast from the operational run, or the, I should say, the control run of the European model,
31:26the ECMWF model. And this shows the temperature over the pole. So this is where we're seeing that sudden stress
31:31threat warming. What you'd expect through the season is that temperature gets lower and lower. This is in
31:35Kelvin. But then you can see it's going up. It's been going up for a week or so. And it
31:40will continue
31:40going up. The forecast peak on Saturday, 7th of November. So that's the sudden stress
31:46threat warming. But what's important, or in terms of definition certainly, and perhaps the tropospheric
31:52response, is whether it will be a minor warming, which is what we are seeing, or a major sudden
31:58stratospheric warming, which is where the winds actually reverse. You get easterlies surrounding
32:03the stratospheric polar vortex. And here we go. This is the wind direction. It's been going more and
32:10more westerly through the season. Then it goes less westerly. The westerlies have been weakening.
32:15But where it crosses this line here is where those winds reverse. And it looks like just from this one
32:22model run that it will reverse through next week. But that's just one model run. And it doesn't show
32:30a huge reversal. It just dips below that line, which is similar to what happened last November. At the
32:36end of November, we had a very subtle reversal. And it's worth pointing out that that didn't result
32:42in colder weather for the UK. Something worth bearing in mind. Again, it looks like from that,
32:49the winds would just go easterly for a little bit. Only slightly. Not a strong easterly.
32:56That's one model run. But of course, we look at lots of model runs. This is what the 50 ensemble
33:01members from ECMWF show. They're all showing those winds going from westerly to just easterly
33:08into next week. Or most of them are. Not all of them. Most of them are showing that. But it
33:13is,
33:13yeah, quite a subtle thing. So it's not the strongest easterly that we'll have seen from
33:20the those winds surrounding the North Pole and the stratosphere. It's very subtle. And then they
33:24they go up again. But it could still have a response on the UK's weather. And that's
33:30the one thing that is most uncertain about all this. We can talk about El Nino's increasing the
33:38chances of sudden stratospheric warmings. That's clear from the science from Adam Scaife at the
33:44Met Office and others. There's an increased chance of this happening. So they are a really good
33:49forecasting tool for the winter because we can say we can flag El Nino's well in advance. We can
33:56talk about them increasing the chances of sudden stratospheric warmings. And then we can talk about the
34:00sudden stratospheric warmings increasing the chances of cold weather in the UK. But what we can't
34:06be certain about is that response, how those anomalous values above the North Pole translate
34:15down into the troposphere where our weather takes place, whether they'll cause a weakening of the jet
34:19stream, blocking highs to develop and where those blocking highs will end up sitting. And at this time
34:25of year, whether that will even result in anything significantly cold or perhaps a greater risk at the
34:32moment, any prolonged dry spells. Of course, we don't want a prolonged dry spell at the moment because
34:38the reservoirs in the South are so lacking in water. So lots of things to consider, big chain of events
34:46that we can identify in modern meteorology that is of great importance. And hopefully, if nothing else,
34:54you found all this rambling relatively interesting and a good way to kill half an hour or more.
35:00But I'll shut up now because there'll be more information on the relatively short to medium
35:06term forecast in the 10-day trend, which is tomorrow. One of the Alex's is doing it. I can't
35:11remember who, I'm afraid. But yeah, Alex will have that, essentially. And for all the latest,
35:18of course, on El Nino and sudden stratospheric warmings, we'll keep your data right here on our
35:22YouTube channel. So if you don't want to miss out on all of that, don't forget to subscribe. Bye-bye.