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This is an in-depth Met Office UK Weather forecast for the next week and beyond. Is a ‘super’ El Nino on the way? and what would that mean for global temperatures and weather extremes. Bringing you this deep dive is Met Office meteorologist Alex Deakin.
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00:00A large, violent typhoon in the Pacific. A super El Nino also in the Pacific. Back home,
00:08things a little more typical for April. It's all in this week's Met Office Deep Dive. My name is
00:14Alex Deakin. Thank you so much for joining me. Thank you for being there. Thank you for watching.
00:17Thanks for your comments. Please do put them in the comments section. Any questions that you've
00:22got, we'll try and answer as many as we can during the Deep Dive or perhaps on our live broadcast
00:27on Friday. But welcome along. Deep Dive. We do this every Tuesday, an in-depth look at what's going on
00:34meteorologically close to the UK, but sometimes like this week, further afield as well. Plenty to
00:41talk about. Do hit that like button, please. And well, if you haven't done already, why haven't you
00:45hit subscribe? Join the 400,000 other followers. Let's get us up to half a million this year. That
00:51would be fantastic. So please do subscribe and share the love. Do you know another Met head that
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01:00to subscribe. All set. Yes. Welcome along to this week's Met Office Deep Dive. More on this beast of
01:07a storm, Sinlaku in the Pacific and more on the UK's weather as well, which is, well, perhaps going to
01:14be the exact opposite of this with potentially high pressure building in as we go into the weekend.
01:19Bit of uncertainty about that. More details on that to come. But first up, a big news story. There's been
01:25steadily brewing over recent days and weeks. El Nino is developing in the Pacific. And earlier,
01:33I talked about it with Graham Madge.
01:37I'm joined now by Graham. Thank you very much for joining us. Graham Madge, do you want to tell
01:41everyone what your role is here at the Met Office?
01:44Pleasure as always, Al, to join you. So my role here at the Met Office is I am a senior
01:49press
01:49officer leading on climate and also a climate science communicator. Excellent stuff.
01:54A fantastically privileged job to work here and cover those topics. Yes, yes. And you do
01:58it so well. You've been on the deep dive before, of course, and many of our other bits of content
02:03that we put out. But today we're talking El Nino, which is in the news, shall we say. And that's
02:10kind of why you're here, because it is quite a big subject and is a growing subject. It's come
02:15onto the news agenda rather abruptly in the last few days. So let's continue to talk about that.
02:21Yes, exactly. So let's first of all deal with what El Nino is. Now we're not going to go too
02:26much into the meteorology in this part. There is a full explainer video on our YouTube channel,
02:31one of our most popular videos of all time. So you can go and watch that. We'll put the link
02:35in the chat to that. So that tells you exactly what El Nino is. But here we're going to discuss
02:40the kind of context, what we could see and what is happening right now. So this is a mapping of
02:46the
02:46sea surface temperatures in the Pacific, which is where El Nino occurs. And this is just to show
02:51the vagaries of El Nino, because it's not a regular thing, is it? It doesn't happen exactly every three
02:57years. There's an irregular pattern to the cycle between El Nino and La Nina. It's one of the biggest
03:03patterns of climate variability that we see on Earth. And what you can see here are the red area,
03:11where sea surface temperature has gone up. And that's El Nino. And that's an El Nino. The
03:16corresponding blue dips are La Nina, which is the cooler phase of the El Nino southern
03:23oscillation cycle. And what I'd like you to have a look at here, Al, is the peak of some of
03:31these
03:31El Nino years. The strongest one. So there's one in the early 80s, and this one in particular,
03:37that's 98. That's quite a famous one. 98. We will come back to talk about that, because that was
03:43a very significant event for a number of reasons. So this is just showing that there's no set pattern
03:49to El Nino, and each one's different. The durations can be different, and it doesn't naturally oscillate
03:54El Nino straight into La Nina. It is very varied. As you can see here, I mean, virtually El Nino
04:03stayed for
04:03several years in the early 90s, albeit quite weak, but just tiny little hint at La Nina,
04:11but largely El Nino. So it's a very varied pattern.
04:15Yeah. And of course, what we are seeing is the temperature in a specific, that's measuring
04:21the temperature of a specific part of the Pacific, which isn't easy to say. So this is where we are
04:26in
04:26the world. There's North America, there's South America, there's Australia, and there is Asia.
04:31We're right in the middle of the Pacific, and it's in this particular box where we talk about the
04:35temperatures, the sea surface temperatures. For it to be an official El Nino, the temperatures in
04:40this box have to be above a certain threshold. Now, different parts of the world determine in
04:47slightly different ways, which doesn't necessarily help the definition, but for the purposes of what
04:51we're going to see, it doesn't really matter, because it's in this part of the world where we're
04:55really expecting temperatures to blossom.
04:57I think a point to make there, you're right, other organisations around the world have separate
05:02definitions, but this will be such a significant event that it will be above all of the threshold,
05:08so there won't be any doubt. If the event happens, we will be in and we'll know it.
05:14And that is what we're looking at later this year, in the coming months. And this is an example of
05:20what
05:21we've seen in the past. This is the 2015 example, imagery of the sea surface temperatures in January,
05:27January the 1st of that year, and then in November later that year. So quite a dramatic shift. You can
05:33see how the sea surface temperatures have risen around the equator. In that area, we looked at
05:38that 3.4 area as it's known. There are other areas that you could measure, and there's lots of
05:43different reasons for that. But the main area, that 3.4 area here, you can see that rise. So that
05:48is
05:48what an El Nino looks like. Historically, that one from 11 years ago.
05:54Importantly, I think that that is the consistent area. So we have a good trend of what these events
05:59look like, based on the observations from that one region.
06:03So we're talking about El Nino, we're talking about the sea surface temperature in that area,
06:06rising by a certain amount. So, what are we looking at right now? What has happened this year,
06:13though, even in the past six weeks or so? This is quite a dramatic couple of images. Now,
06:18this isn't temperature. I was quite taken by this. This is imagery from space, from the satellite,
06:22from Sentinel-6. But it's actually measuring, it's not measuring sea surface temperature,
06:26it's measuring the height of the sea. Again, an anomaly of the height of the sea. It's amazing,
06:32it can get this amount of detail. And of course, an expander, a warmer sea expander. So that's what
06:39we're measuring here. So a rise in sea surface levels is indicative of higher temperature. And
06:45it's a really stark difference between the start of March here, and the most recent image,
06:50right at the end of March. So within a month, we've seen this area grow, blossoming, of higher
06:55sea surface levels, indicative that we're seeing a warming in this part of the world.
07:00It's quite stark, isn't it? Yeah. When you look at that, to see how pronounced and well-defined
07:03that is. That is. That really is. Now, that isn't necessarily in the 3.4 area. That's slightly,
07:09a little bit further east, actually. But it's showing you in this zone, and you can imagine
07:14with westerly winds picking up, we've seen a burst of westerly winds in this area. All that warm areas,
07:19all that warm sea, rather, is going to develop more widely in this zone, in the El Nino 3.4
07:25zone.
07:26And that is what we're likely, that is what we're expecting to see. And this is showing that really
07:32quite nicely. So this is the main bit that we're talking about. This is in that zone, Nino 3.4,
07:37that area. Sea surface temperature. And this is the projection. So this is the forecast in red,
07:43going forward along the bottom. The black line is what has been observed. So temperatures were
07:48slightly below average, the back end of last year. And they've been rising steadily. And they crossed
07:54the zero thresholds in February. And now we're here, in terms of what's been measured. But the red
08:01line is the forecast going forward, when we use ensemble forecasts. Important to say, Al, I think,
08:07that these are relative temperatures. Yes. To what we would get in terms of average. Yeah. So think
08:14of this as a rise above, rather than actual value. Yes. Yeah, complete. So that zero line is the average,
08:19and anything else is an anomaly above. That's why we're talking El Nino. Above 0.5 Celsius,
08:24that's how NOAA define an El Nino. So we're getting into that zone in the springtime, certainly coming up,
08:31not far away. And if it was La Nina, it would be the opposite way. So we're... But you can
08:36see what I
08:37mean now by saying how definitive this will be. Yeah. So some organisations, 0.5, 0.8, kind of irrelevant,
08:45when we get to this stage. Because if it goes in line with projections, then nobody's going to deny
08:51that that's not an El Nino event. Close to two degrees above average. Now let's take a closer look
08:55at the forecast with the very most recent data from the Met Office scientists here. This is May to
09:03September. So what are we looking at here? So what we've got here is the central estimate for the
09:10projection for what temperatures we think, or the model thinks, is going to be realistic. So you can see
09:17that by the end of, well, end of August, September, we're actually pushing one and a half, two degrees,
09:26and you can see that that's still got a trend to go. One thing here that I'd really like to
09:32draw your
09:32attention to is the fact normally we're quite used to seeing these sorts of graphs, aren't we? We have
09:37to interpret them as part of our jobs. But look at how close that is in terms of all these
09:44different
09:44runs from the model, and they're all telling us more or less the same thing. Yeah. And that is quite
09:51unusual. Sometimes you'd expect some of these ensemble members, we call them, to actually be
09:56right down here and that pattern to be more confused. Yeah. I can't recall it really seeing it as
10:02consistent and uniform. So that tightness gives you confidence. Gives you confidence. Exactly.
10:08That's basically what we're talking about. So each of these individuals thin red lines,
10:11hopefully you can see them there, is an ensemble. So we talk about ensembles quite a bit in the deep
10:15dive where you run the same model with slightly different initial conditions. Again, there's
10:20videos on that we can watch. But actually these dotted lines are the most more recent model runs as
10:25well. Three of the more recent ones from, they run them every week. So from the end of March,
10:30the very end of March, and then the first week in April. They're all agreeing as well,
10:33as well as the most recent ensemble ones, all of them tightly packed together. Often when we show
10:37ensembles, as I'll do later, actually, there is much more variance, particularly with something
10:44like this. And you get those ones that spin off and it all broadens out quite a bit. The
10:49tightness of that, all indicative that we're all going to be above that threshold of 0.8 or 0.5
10:54very rapidly. And that is likely to continue through the summer. And, you know, the trajectory
10:59of that we're taking further. And El Nino often peaks at the end of the year, November, December,
11:04January is often the peak of an El Nino. So we'll have to see where this occurs. Now,
11:09there's been a lot of chat, Graham, in the press about the super El Nino. So what are we talking
11:15about with a super El Nino? Is there an actual definition? Well, there's a bit of a little bit
11:20of journalistic license by calling it a super El Nino event. It's not a term that we're subscribing to,
11:27but it does underpin the fact that this is likely to be a significant event. And I think,
11:33you know, we get another hint from that. We've talked about the tightness of this band. Yeah. But
11:38look at the, look at the height of it. Yeah. We're not talking about a tight band here. We're
11:43actually almost nudging the top of the graph. So, I mean, one degree above the average, a one degree
11:50anomaly would be a fairly weak El Nino. But we're talking up to two degrees. So that would be
11:56classed as a strong, as a strong one. So it's likely to be, the scientists tell us that it's
12:01likely to be the strongest El Nino event so far this century. Wow. Okay. And we're probably comparing
12:08it to a 1998 event. That was the peak we showed earlier. I remember 1998. I couldn't possibly say
12:15whether you do, but. It was a World Cup year. So I always remember those years. So 98, you pointed
12:20out earlier on that peak graph, that was a really strong El Nino. And this is comparable to that
12:25likely to be. And in that year, the temperatures in that area are around about two degrees above
12:30average in that crucial area. So it's definitely comparable. World Cup of Science. That was a really
12:35significant year. And it's another World Cup year. Who won in that? Who won in 98?
12:38France won. Ooh. Maybe there's a link. Maybe there's a link. We will find out later. The Met
12:45Office does not advocate gambling, just to make that clear. But that's really interesting the way
12:51that goes forward. And that is strong indication. So yes, we are expecting El Nino to develop in the
12:58coming months. And it is very likely to be quite strong El Nino. What does that mean? Okay. The sea
13:05surface temperature in the middle of the Pacific is warming up. Who cares? Well, it turns out it's
13:10quite important for a number of factors. Let's deal firstly globally, and what that could mean
13:16for the global temperature. And that's what this graph is showing here. All right. So this is
13:22something I'm very familiar with, in terms of dealing with global temperature. So the white line here is the
13:30actual surface global temperature for each of the years. And you see it's quite a variable line. But if
13:39you draw a trend line through that, you can see that it's increasing. So that's climate change. From 1990 to
13:452023, there is a rise in the global temperature.
13:49Indeed. But more observant, we'll notice that there's peaks and troughs. Yeah. And what we've done here is we've put
13:57an orange bar representing a year when there was an El Nino year. And you can see that a lot
14:04of these peaks
14:05actually align with El Nino years. So that's really quite important to remember.
14:12This is a temporary thing. So an El Nino will impart heat to the atmosphere, and generally raise global average
14:22temperature by about a fifth of a degree Celsius.
14:25Right. Okay.
14:25Or two Celsius. Okay.
14:281998. We've mentioned that for several reasons.
14:31But it was a significant year for global temperature. And at the time, it was the warmest year on record.
14:39Okay.
14:39Now, let's hold that thought.
14:41Yeah.
14:42Because La Nina years, the blue lines, actually cool temperature a little bit.
14:48So you can see that there's corresponding troughs where you get La Ninas.
14:53What I want to draw your attention to, Al, is the fact record year, given a boost by the significant
15:00El Nino of that year.
15:02But look at how background temperature has risen. So by the time we get to here, the late 20 years
15:12later, we've got a year that is warmer than 1998, when it should be a cool year because of the
15:20influence of La Nina.
15:22Yeah.
15:23So the El Nino and La Nina impart a temporary effect on global temperature.
15:30But you can see that trend.
15:31But you can see the rise as the temperature is coming up due to anthropogenic emissions.
15:37The three most recent La Ninas are still quite a bit warmer than that.
15:42That really powerful El Nino back in 1998, 1995 there as well.
15:48And the 2015 one there that we showed earlier from the globe of that change.
15:53Again, that was a peak.
15:54But the next year was even warmer still with another.
15:56And it can lag, can't it?
15:58Because it often peaks at the end of the year, it doesn't necessarily mean that year.
16:01You can have an El Nino in 2015, like this year.
16:04And if it peaks at the end of the year, it will take that temperature into the following year as
16:09well.
16:09So you often get that lag and that peak effect.
16:13So if we look at this, so we had the first 1.4 year in 2023.
16:22Yeah, that's that.
16:23So 1.4 above global temperature, above the pre-industrial levels.
16:28So that was the first year above 1.4.
16:31We've had two more years above 1.4, boosted by the El Nino.
16:36We have to concede that it's not all down to emissions.
16:40But look at the headroom.
16:42So 1.5 Paris Agreement threshold, trying to keep global temperatures around 1.5 or below if we possibly can.
16:51But look how close we are now to that headroom.
16:54And with an El Nino, it's likely that next year it will be a year above 1.5.
17:01So we'll actually see that.
17:03And with a powerful El Nino as well, because this wasn't classed as an El Nino year, but it wasn't
17:06a particularly powerful one.
17:08We are expecting, or there's a very good chance that this year will be a powerful one.
17:11It's way too early to call it a record year for next year.
17:15But if all of these things happen in line with the forecasts and projections, and that there isn't a massive
17:22volcano, which would help, eruption, would help suppress global temperatures, it could be a record year.
17:29And our experts are saying it's likely to be a year above 1.5.
17:33Well, OK, OK, so watch this space again.
17:35You heard it here first.
17:37That's really interesting on a global perspective.
17:40But also El Nino has quite dramatic effects regionally, doesn't it, across the world, across the world.
17:45So let's take a look at that.
17:47Now, apologies in advance for my poor drawing on this, but I have scribbled out, and it really is a
17:54very quick scribble, some of the areas across the world that are affected by this.
17:58Because, as you can imagine, what we're talking about is, I'll zoom out a little bit more so you can
18:04see the world a little bit better.
18:06We're talking about temperatures in this area, sea surface temperatures rising.
18:10And that has all sorts of implications and effects around the world, changing the distribution of rainfall.
18:17Because instead of the warmth being over here and rising air, and you've got a lot of wet weather, actually
18:24what happens is you get drier conditions in Australia, in the east of Australia.
18:29And it's the areas closest to that El Nino zone that are affected the strongest, as you would imagine.
18:35Can you just go back a sec now to the Pacific?
18:38Because I just want to draw attention to something here.
18:40So we're saying that the El Nino will have an impact in this region, but when you look at that
18:47hemisphere view, there's hardly any landmass within it.
18:52It's all ocean.
18:53So this is an event that happens possibly farthest away from the majority of human population, but has such a
19:00significant impact on people's lives around the world.
19:03I think that's something that we should draw attention to.
19:06Very, very, very valid point there, Grant.
19:08Interesting to see the glow from this perspective.
19:10Particularly with people coming up with the Artemis imagery that we saw recently as well.
19:16So it's happening in this part of the world.
19:17I should have said that my drawings actually, the yellow in here are areas of the world that are dry.
19:24In an El Nino year become drier than average.
19:27You see a drying effect in the yellow areas, and the blue are areas that are wetter than average in
19:32an El Nino year.
19:34Now the areas, as I said, that are closest to this zone are the areas that are most affected.
19:38And what we see, and again, I'm not going to go into the details of the meteorology, that's in a
19:42separate video, you can find out more about that.
19:44But roughly speaking, you get less, because it's not as warm here, you get less ascents, you get less thundery
19:49showers in eastern Australia.
19:51So it's drier in Australia, and right across southeast Asia, it's drier in an El Nino year.
19:57Certainly southeast Asia, the western Pacific generally, eastern Australia, and Indonesia can all expect, on average, drier conditions.
20:08Now again, part of my drawing, we'll probably put the link again in the chat about the actual maps, the
20:14scientific maps, because I've just kind of scribbled these on.
20:16But India, again, highlighting that as an area that's drier than average in an El Nino year, that's so important,
20:21because the monsoon rains, you know, provide so much of the infrastructure to India.
20:26So vital crops.
20:27So important for crops and everything.
20:29So drier than average here.
20:30Central parts of Africa tend to be drier than average, along with much of southeast Africa.
20:35And then we're back to South America, where some of the biggest impacts have felt, because we're closest to the
20:42actual event.
20:43And a large swathe, northern parts of South America, into Central America, are drier than average in an El Nino
20:50year.
20:50Now, again, important to stress, not just my dodgy drawing, but different parts of the world are affected at different
20:55times of the year.
20:56It's not like for a whole, for the whole year, it's drier than average, different parts.
21:01And again, we'll put the full maps in the chat.
21:04But this could be quite important, couldn't it?
21:06Because drier than average in this part of the world.
21:08So the region covered by your yellow highlight there is the Amazon.
21:12Yeah.
21:13Clearly a very important place, not just within the regional context of South America, but globally.
21:19Controls a lot of the global climate, actually.
21:23It's a bit of a break on the climate.
21:25So when you've got drier conditions in Amazonia, and you've also got elevated temperatures likely in the region, we know
21:34that this region is already extremely fire prone.
21:39So we're not making any predictions here, but if the trend follows through, it's exceedingly likely that we're likely to
21:48see, on balance of probability, more wildfires in that part of the world.
21:54And that's really significant, isn't it?
21:57It's a cycle, isn't it?
21:59It's a positive feedback loop, because if you burn more of the trees, they're not taking out as much of
22:05the carbon dioxide from the atmosphere.
22:06Absolutely.
22:06And you're putting more carbon dioxide into the atmosphere, so that could be disastrous on a number of them.
22:12So yes, I just want to do a bit more drawing, because I always love drawing on it.
22:15So this area is also warmer than average.
22:18So the red now means warmer than average.
22:19And if we go around the world, and again, highlighting these areas that are drier than average, if you check
22:25the map, you can also see that actually large parts of Southern Australia are warmer than average in an El
22:30Nino year, along with Southeast Asia.
22:33These are pockets, again, where you've got that overlap of not just drier than average, but also warmer than average
22:39conditions in the Southeast of Africa also.
22:43So it has a number of effects.
22:46They're not always, you know, as direct every year.
22:50Every El Nino is different in terms of its intensity and how widespread it is, but also the actual knock
22:55-on effects, because it's obviously a very complex system.
22:57There are other global drivers affecting it.
22:59But the closer you are as a rough guide to the actual warming of the seas, the more direct the
23:06link is.
23:07Talked about wildfires, and one area that has suffered from wildfires recently, California.
23:12Interestingly, in El Nino year, California gets more rain on average.
23:17So there's a possibility that that could certainly help the forthcoming fire season by creating more rainfall, keeping conditions wetter,
23:27perhaps preventing more of the ignition of the forests and suppressing any fires which do break out.
23:33Again, not a forecast, but looking at general trends and probabilities, that's likely to happen.
23:40Another possible event that could be connected to El Nino is the suppression of Atlantic hurricanes.
23:49Yes.
23:49So very important this time of year.
23:52Everybody wants to know what the forthcoming hurricane season is going to be like in the Atlantic Basin.
23:57Obviously, it affects and impacts in the Caribbean and wider, but you'll know more about the meteorology of this than
24:05I.
24:05Yeah, interesting that the seas obviously play a huge part in that.
24:08But actually, it's often more to do with the wind shear that prevents.
24:12When in El Nino year, you get more wind shear in the Atlantic Basin, and wind shear kind of breaks
24:17up hurricanes and stops them from forming.
24:19So that is an area where you would expect.
24:22In El Nino year, if we're going to get an El Nino year, you'd see fewer storms.
24:25But by contrast, and as I'll talk about later, with warmer seas here, it fuels more storms in the Pacific.
24:33But let's quickly just go back, because I've got quite an interesting graph to show that rainfall in Southern California.
24:40And in an El Nino year, this blue line, so we're going to date along the bottom here.
24:44The wet season tends to be in the autumn into the early winter, early spring.
24:50That's the rainy season in Southern California.
24:53And this would be a typical year.
24:57And in an El Nino year, you tend to get this.
24:59So you get heavy rain.
25:00Often you get 100% the annual rainfall by mid-February, because you're above that, where it gets very dry
25:06very quickly.
25:06So within El Nino, perhaps speaking later this year, it may not have an impact on this fire season.
25:12It may potentially have more impact on the next fire season, because it's more likely to influence the rain as
25:17we go into this autumn and the next spring.
25:21But just quite an interesting example there of how El Nino directly does affect the weather in other parts of
25:28the world.
25:29We are always going to get asked this question.
25:31We get asked this question quite a bit.
25:33And so I need to ask you, Graham, what about impacts for closer to home?
25:39What about for the UK?
25:40Does El Nino mean anything to the UK?
25:43So clearly you've mentioned that El Nino happens in a region of the world that's almost as far away from
25:50Europe as you can get, really, in the tropical Pacific.
25:54There are sometimes observed teleconnections between what happens in an El Nino year and what happens in the UK's weather.
26:03But what I would say to you, and I don't know why I'm telling you this, because you know this
26:07better than anybody.
26:09The influence of El Nino is a significant driver in global weather and in our weather, but it's not the
26:16only one by any means.
26:17So we're often using this analogy of European weather as a bit of a battleground with all these various influences
26:25coming in.
26:27It's possible that we could see some impacts from El Nino, but equally possible that we could see other drivers
26:35being more dominant, even though we've referred to the fact that this is a significant event.
26:41So it's way too early to say what this is going to mean for a British winter or a Northwest
26:47European winter.
26:49We will have to do a lot more understanding and forecasting to know how strong those other drivers are in
26:57terms of how all those different entities will interact with each other.
27:02And the consequence of that is what we get in the weather forecast.
27:05Absolutely. Thank you. Great. Well put.
27:07And there are, if you want to know what all those drivers are, you know, things like the Atlantic Oscillation,
27:13North Atlantic Oscillation, the Arctic Oscillation.
27:16There's all kinds of different drivers, the quasi-biannual variation as well.
27:20There's a whole video all about them.
27:22So we're going to make sure Rich is really busy by telling him to put the link to that in
27:26the chat as well, because we made a whole video about it.
27:28I think it's on presenting it about all the different drivers of which El Nino is just one.
27:34And as we mentioned, the closer you are to El Nino, the bigger the effect is.
27:37And it's a long way from here. So the links, there are some, but they're weak at best.
27:43Graham, thank you so much.
27:45Really, really enjoyed this chat. I hope you have enjoyed it as well.
27:48Thank you very much for joining me on this week's Deep Dive.
27:50Pleasure. Thank you.
27:53Always fantastic to talk to Graham on the Met Office Deep Dive.
27:57Such a knowledgeable chap. And yeah, really interesting stuff there about El Nino.
28:02Right. Let's get back to the UK's weather, because it's a fairly typical April fare through much of this week's
28:08spirals of low pressure.
28:10Not far from the UK further brewing out in the Atlantic as we've been through this week.
28:15And this one in particular, an area of low pressure that will control our weather in one form or another
28:20over the next couple of days.
28:22What's going on? What's the bigger picture? Let's show you the jet stream.
28:25This big dip in the jet stream. And that's that low pressure we saw a minute ago on a satellite
28:30image.
28:31And because it's kind of in this dip in this trough, it's not really doing very much, not really interacting
28:36with the jet stream.
28:37The whole system is kind of just bodily moving from west to east.
28:42And these old weather fronts are then, as a result, kind of flinging out across the UK, bringing a lot
28:47of cloud and some outbreaks of rain.
28:49The whole package does move a little bit closer.
28:52So we'll see some heavier rain on this cold front in particular as it crosses the UK tomorrow.
28:57And then, well, there's another little low waiting in a similar position.
29:02But if we stop it there by the time we get to Wednesday, the jet stream's kind of weakened.
29:06It's not as developmental. It's more in a straight line.
29:09Still a bit of a dip. So still some intensity to this low pressure.
29:13And as that develops and comes in, again, notice you can't really see the pinks anymore.
29:17The jet stream has weakened, but it's still a fairly intense area of low pressure with weather fronts that are
29:23going to bring us another spell of wet and windy weather,
29:25particularly the closer you are to that low as we head into Friday.
29:31And then notice the jet stream's got a broken, fragmented.
29:34And look at this little area of high pressure potentially toppling in as we go into the weekend.
29:40High pressure means sinking air, a lot of dry weather and potentially some sunshine, particularly for Sunday if it does
29:46crop up.
29:47Before then, though, plenty going on.
29:49Just rewind the clock because if we just zoom all the way over to the United States,
29:55I just want to show you this because there's two jets across North America being greedy.
30:01Both the jets kind of coming together. You often get two jets across the U.S.
30:05because it's such a large landmass, U.S. and Canada, I should say, North America.
30:10But the fact that the two jets are kind of coming together, polar front jet and the subtropical jet coming
30:16together is quite unusual.
30:18That's not just one jet splitting. That's two jets getting very close together.
30:21That's quite an unusual setup and is driving a bit of the uncertainty as we head towards the weekend.
30:27More on that in a moment because, as I said, low pressure systems coming our way for the next couple
30:31of days.
30:32So what can we expect? Well, I mean, I call it April showers in the week ahead forecast,
30:37which if you're a meteorologist, you should be shaking your head at me because it's not really April showers because
30:41this is more frontal rain coming in.
30:43But because it's fragmented and people see a bit of rain and it stops and a bit of rain and
30:47it stops.
30:47I was quite happy to call it showers because it's kind of a bit more on and offy.
30:50But technically speaking, not really showery because, as I say, these are our weather fronts that are moving in,
30:57bringing a lot of cloud and some outbreaks of rain, particularly if we go back to tomorrow and zoom in
31:03a little bit to show the UK.
31:04There's that cold front coming in. A bit of anger to that, a bit of angst because the jet stream's
31:08just getting that little bit closer
31:09and the low's a bit more developmental.
31:11So some heavier rain coming in for a time as we go through tomorrow across Wales, southwest England.
31:17A spell of rain will then work its way across the UK during the day.
31:22But ahead of it, some warm air tucked in here.
31:25So if you get a bit of brightness in eastern areas, it will be quite warm tomorrow before this rain
31:30band spreads its way through,
31:32which, as I say, could be on the heavy side.
31:34Then Thursday's a drier day. Yes, a few showers here and there, but we're kind of between those two weather
31:38systems.
31:39And then that next one comes in on Friday.
31:41But again, notice parts of the east maybe not seeing too much.
31:45It's all because the lows here, everything's orientated around that way.
31:47So a lot of the rain bands coming into the areas that see a lot of rain.
31:52So Wales, southwest England and western Scotland, along with northern Ireland.
31:56If you did watch my week ahead video yesterday, I showed the accumulations of the rain through the week.
32:00And it was always those western areas that soar the most with just a few showers at times getting into
32:06the east.
32:06So that sets us up for the next few days, the rest of this working week.
32:11After that, well, uncertainty does grow a little bit.
32:14But as that system moves through, you can see it there.
32:17Let's put it on the broader picture again.
32:21Fast forward to Saturday.
32:23And there's that low coming in for Friday, bringing some wet and windy weather.
32:28But for Saturday, it's still there across Scotland, bringing some outbreaks of rain.
32:33Cold front to clear through.
32:34Weak jet stream there.
32:36And that's when the high pressure starts to topple in.
32:38So there are quite strong signs that we will see higher pressure building in for Sunday across the south.
32:47So southern air is seeing high pressure.
32:49Again, high pressure means the descending air.
32:50So the winds will be lighter and was a good chance of seeing some sunnier skies, at least for a
32:55time through the weekend across the south.
32:56But with this low here sitting still across Scotland, that would still be producing quite a lot of cloud and
33:02quite a few outbreaks of rain for Sunday.
33:05Fast forward to Sunday.
33:08According to the Met Office model, at least still a lot of showers across the north, drier and sunnier in
33:14the south.
33:15Not particularly warm.
33:16No temperatures still only in the mid-teens in places.
33:19So that's an area we need to watch because not all the models are agreeing with that pressure pattern.
33:23High pressure to the south, low pressure to the north.
33:25There is a little bit of uncertainty, which I can show you by looking at the European model.
33:31ECMWF, what does it think is going to happen at the weekend?
33:34It's similar.
33:35Where have we got?
33:36This is Sunday.
33:37Now, look at this.
33:39For Sunday, the European model has the high sitting right over us.
33:44No low near Scotland.
33:45So that would mean dry and fine and generally sunny weather for pretty much all parts of the UK by
33:50the time we got to Sunday.
33:52So a bit of a discrepancy there.
33:55Not all of the ensemble members are showing this, but many of them are.
33:59We can probably pick out quite a few.
34:01So if we look at number three, again, that's got high pressure.
34:04So the ensemble is when we run the model with a slight tweak at the start.
34:08And these are the European ensemble models.
34:11That's number eight.
34:12A lot of them have high pressure in and around the UK for that same time period for Sunday.
34:17But we can probably pick out one or two that do have something similar to the Met Office model.
34:22There's the low pressure sitting across Shetland at this time, which would still generate quite a lot of showers across
34:27Scotland.
34:28And there are a couple more.
34:29There's number 14.
34:30It's got low nearby 15.
34:32Well, if you squint a little, there's a low pressure there.
34:34But most of them do have that high pressure.
34:38But there's 19.
34:39It's still got low pressure, but it's a little further north.
34:41So quite a strong signal.
34:42High pressure is moving in.
34:43The Met Office model perhaps a little pessimistic with that low sitting still across Scotland.
34:49And see the European model a bit more bullish about when that high pressure moves in.
34:53Why the discrepancy?
34:54Not a huge discrepancy.
34:56Not unusual to have that amount of difference at this lead time.
34:59This is Sunday.
35:00We're recording this on Tuesday.
35:01So that's five days.
35:03So there's nothing unusual.
35:04But I just thought I would show one of the reasons or where that discrepancy is coming from perhaps.
35:11Because that's quite interesting relating to what I talked about earlier with the jet stream.
35:15So this is, there's the UK in there.
35:20And this map is showing the difference between the EC, European model, and the Met Office model.
35:26High up in the sky, around 10 kilometers up.
35:29The 250 hectopascal zone.
35:34And the areas are basically showing the pressure pattern high up in the sky, around about 10 kilometers.
35:40And the black line, the dotted line, are the two different models.
35:42But crucially, what you can hopefully pick out are the blobs, the blues and the yellows.
35:48You take one away from the other.
35:49And that gives you the difference.
35:51So this is showing the difference between the Met Office model and the EC model.
35:56If they were the same, you wouldn't get the blue blobs or the yellow blobs.
35:59So where you've got differences, that's where the blobs are showing up, where there are differences.
36:04And by the time we get to, this is Friday.
36:06So this is in that development zone out, there's the UK.
36:10And these kind of four quite significant blobs at this stage are where the models aren't agreeing.
36:15But what was interesting, and I must thank Mark, the Deputy Chief, for pointing this out during the morning brief
36:22this morning,
36:23is where that's actually come from.
36:24If we go back, so that was for Friday, this is for today at 6 p.m. this evening, Zulu
36:32time.
36:32And this is again showing that same thing, but there's now much more agreement.
36:36Yeah, there's a bit of a paler blue zone down there, but much more agreement generally out across the Atlantic
36:42with the UK here.
36:43But this is where that error stems from, or that's where the biggest difference is at this stage.
36:49And if we play through time slowly, so if we forward it on to tomorrow, is it going to play
36:55through?
36:57Or there you go.
36:58That difference translates and moves out across the Atlantic.
37:01Keep your eye on that, and we can track it.
37:04And that is basically where that difference comes in as we head towards Friday and then into the weekend,
37:09which is ultimately responsible for that difference in the way the models are handling,
37:14the high pressure and the low pressure and how quickly it comes in.
37:18And it originates, you can track it back, and it originates those differences.
37:22You can track them back to that part of Eastern Canada.
37:26In fact, I'll just scroll back on here.
37:28There we go.
37:29Hopefully that's going to do it.
37:32Oh, it's gone very slow.
37:34Come on, you can do it.
37:34You can do it.
37:36Let's go that way.
37:37I'll just come back to it that way.
37:40And then you can see, oh, why is it not behaving?
37:48There we go.
37:49That's what I want to show.
37:49This is where we're at now, and it's that difference.
37:52You can trace it back to that difference across Eastern Canada, which goes back to that funky jet stream,
38:02or the two jet streams kind of coming together in an unusual formation.
38:07So there's the two jets coming together like that, being so close together.
38:10That's not a splitting jet.
38:11That's two different jets coming together, being so close.
38:13So that is where the area of uncertainty generates from.
38:17And you can see why when you've got that quite unusual setup.
38:20Obviously, the models are better at handling things when they see them more frequently or more typical positions.
38:24So that is where the potential discrepancy around the weekend comes from.
38:29So I just thought I'd show you that because it was quite interesting.
38:31Again, thanks to Mark, our Deputy Chief Meteorologist, for pointing that out this morning in the brief.
38:38Obviously, we'll have more on the weekend's weather and into next week in the 10-day trend tomorrow with Annie.
38:43So another reason to subscribe, and then you won't miss that.
38:46And while you're there, if you're enjoying this, do hit that thumbs up.
38:49It does make a big difference.
38:50Thank you very much.
38:51One more thing to talk about, which is kind of linked to El Nino earlier.
38:57We talked with Graham about the developing El Nino.
39:00We saw how the sea surface temperature is already starting to develop in parts of the Pacific.
39:06And one thing that El Nino does tend to do, it suppresses hurricanes in the Atlantic,
39:11but it encourages more tropical cyclones in the Pacific.
39:16And that is what we're seeing.
39:17And this is a particularly powerful, powerful storm.
39:20If you look closely, you can just about make out the Mariana Islands in there.
39:25If you look and get the right frame.
39:26This is on Tropical Tidbits.
39:28This was from this morning.
39:30There is a more up-to-date one I saw just before I came and recorded this.
39:34But you can go and find it for yourself if you go to Tropical Tidbits.
39:36It will actually be crossing now.
39:38The storm crossing the islands, if it hasn't done already.
39:41And you can see that, the eye of the storm, going across the Mariana Islands.
39:46Significant impacts from this storm.
39:47This is a powerful storm, equivalent to a Category 4.
39:50It's called a large because of its size, but violent because of the strength of the wind.
39:55Average winds, sustained mean winds, 120 miles an hour.
40:01So, yeah, equivalent to a Category 4.
40:04Weakening a little bit as it tracks north.
40:05It's going to still be that Category 3, Category 4, as it tracks its way over the next few hours.
40:12Those kind of winds are likely to cause damage.
40:13Now, this part of the world, where are we?
40:15Let me show you that because that might help.
40:17It doesn't really see it on there.
40:19Let's head, zoom out, head around the other part of the world.
40:24Quite easy to spot it.
40:25That's where we are.
40:26So, there's Japan.
40:28There's Australia.
40:29There's the Philippines.
40:30So, we're in this part of the world where we saw earlier that sea temperatures have risen.
40:35And that, again, is part of the reason.
40:37Feeding these big storms.
40:39There was another one on the southern side of the equator that's died out now.
40:43But this one is particularly intense, particularly lively.
40:47If we zoom right in, can you see those islands?
40:50Yeah, just about.
40:50There's Guam.
40:52And then there you're into the northern Mariana Islands in there.
40:55As this storm is crossing, as I record this right now, a very powerful storm indeed.
41:01Those winds, 120 miles an hour, that's the mean wind speed.
41:05Gusts are going to be larger than that.
41:06So, we're expecting structural damage.
41:08It's also going to drop a lot of rainfall.
41:11Five to 600 millimeters of rain could fall.
41:14Now, most of it's going to fall overseas.
41:15But if the islands get that kind of amount of rainfall, that is going to be significant, likely to cause
41:20mudslides.
41:21And there'll be large waves associated with this storm as well.
41:24So, we are expecting some significant issues from this storm system.
41:28This part of the world obviously gets quite a lot of tropical storms.
41:31But not necessarily at this time of year.
41:34This is very early in the season for such a powerful storm.
41:39Paul, on our global guidance upstairs, again, one of the meteorologists here.
41:45He was saying they've had a similar storm, but that was in April, but it was later in the month.
41:50It's very unusual to have such a powerful storm hitting this part of the world.
41:54Five to 600 millimeters of rain.
41:56That is the equivalent to what London sees in a year.
41:59So, you know, in a day or so, they could have the same amount that London or the southeast generally
42:04receives in a year.
42:05So, that is, again, likely to cause some problems and some mudslides along with those powerful waves.
42:11What happens to it next?
42:12Well, it kind of migrates slowly northwards and will eventually start to weaken.
42:17But it maintains something of its strength, certainly for the next 36 to 48 hours.
42:22And it will affect the more northern parts of the Mariana Islands, the less populated areas.
42:27But there are still, you know, thousands of people living on these islands.
42:30So, this is a significant storm affecting this part of the world before it kind of weakens a little bit
42:35as we head later in the week.
42:37Let's fast forward a little bit.
42:38You can see it filling a little bit and then drifting northwards.
42:40If I put it on during the day, then you can see the islands a bit better on there as
42:44well.
42:45So, there we are crossing here, going then, but still affected.
42:48It's quite an unusual path, very close to all of the Mariana Islands.
42:51So, that's quite unfortunate that most of the islands are going to be affected by the storm with the heavy
42:56rain or those strong winds.
42:58So, that is something we'll obviously be tracking very carefully.
43:01I say you can go and view those images for yourself, the eye of the storm actually going across.
43:08Right, that's about it, I think, from me for today.
43:11Again, thank you to Graham.
43:13Thanks to Mark.
43:14Thanks to Paul from upstairs, from the guidance unit for their words of wisdom also today.
43:19I hope you've enjoyed it.
43:20As I say, if you have, please let us know in the comments.
43:23But also, do hit that thumbs up button, the like button, and spread the word.
43:28Let everyone know that the Met Office is here doing weathery things every Tuesday.
43:33Join us for the live on Friday.
43:35It's Annie and I doing it this week.
43:36And Annie's got the 10-day trend for you tomorrow as well.
43:39But from me, for now, goodbye.
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