This is an in-depth Met Office international Weather forecast for the next week and beyond. Spring sun in the UK and downpours in Iberia and north America. Bringing you this deep dive is Met Office meteorologist Alex Deakin.
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00:00Spring sunshine by the bucket load. If you like blue skies it has been a
00:05bobby-dazzler of a day today. But how long will the sunshine last? How warm
00:10will it get? Where's the rain? Clue? It's in Spain and Portugal. And we'll have
00:16quite an international flavor to this week's Deep Dive because we're also
00:19going to be looking at the severe weather in the United States. Tornadoes
00:23yes, but plenty more besides as we will find out. Welcome along to the Met Office
00:29Deep Dive. My name's Alex Deakin. Thank you very much for being there. Please
00:33leave a comment. Most importantly give us a like and share the love. Let other
00:38MetHeads know that we are here. Every week we dive into some kind of
00:44meteorological majesty and take a really close look at various aspects of the
00:50weather in the UK. But also as we'll see particularly this week things going on
00:55around the world. Let us know in the comments if you like that. If you'd rather
00:58focus on the UK. If you like the international side of things. Let us know
01:02what you want to hear about. We will try and tailor our deep dives going forward
01:06to what you require. We do read try and read all of the comments and try and
01:12respond to some of them as well. So do please leave a comment. Do please give us
01:16a like and do please share this amongst your friends and family and as I say
01:21fellow MetHeads. Lots and lots and lots to talk about as always. Let's start with
01:27the bigger picture. Here's the satellite image. It's kind of telling the story
01:31quite nicely. If we fast forward to the here and now. Well largely clear skies
01:37across the UK. Look at that. Yeah there's a little bit of Stratocume lingering
01:42across Stratocumulus lingering across Shetland. It was a cloudy start for
01:46Northern Ireland but even here it's brightening up for many places. It has
01:49been a sparkling day of sunshine. We'll talk about the UK weather in a moment
01:54because first of all I want to draw your attention further south. It has been a
01:57very wet spell over Iberia. I was fortunate enough to be there a couple of
02:01weeks ago. Got very wet and windy and well there's more of that to come. We've
02:06seen this plume of cloud bringing further rain and well out in the
02:11Atlantic. Just look at that. You can tell by that. That's not great
02:15weather. That big dip that is an area of low pressure and that is going to bring
02:20more wet and windy weather to Spain and Portugal over the next couple of days
02:24and it's all to do with a dip in the jet stream. The jet stream is driving
02:28its way southwards and helping to develop that low pressure in here and
02:32it's all slowly but surely heading its way towards Iberia. We're going to see
02:36more wet weather here over the next day or so. How much wet weather? Well let's
02:41take a closer look at what's going on and the rainfall accumulations. Let's
02:48zoom in a little bit on that. Let's put them on as blocks and we can really see
02:52we've got some heavy rain. This is the 24-hour rainfall accumulations. You can
02:57see some quite heavy pulses right across eastern parts of Spain and just to the
03:01north of Madrid. That's happening at the moment but if we zoom out a little bit
03:06and focus in on Portugal and play through towards Wednesday. Look at these
03:14tower blocks building up. Heavy rain really building up on the coastline
03:18there. Pretty wet also across the Algarve. Those amounts in that 75, greater
03:25than 75 millimetres up to 100 millimetres of rainfall. That basically
03:29equates to the whole March average if not higher for this part of the world. So
03:34yeah months worth of rain likely to fall in a day or so. Not just wet but also
03:39very windy too. So that rain will then spread steadily. It won't be as heavy across
03:44Spain but further pulses of rain to come here particularly across parts of
03:48southern Spain as we go through Wednesday and into Thursday. So yes some
03:52very wet conditions for Spain and Portugal. Weather system's actually been
03:56named as Storm Martinho by the Portuguese Weather Service and you can
04:01see why because again as we just play through that. Let's take the jet stream
04:04off. Just see that weather system coming in. Look at the isobars really squidging
04:09together there. That's tonight. The strongest winds tonight and tomorrow on
04:14that Portuguese coastline. That is not going to be very pleasant. Don't want to
04:19be playing golf in it. Don't want to be out in it at all. Look at that with those
04:22strong winds really coming up from the southeast across Spain and Portugal
04:27tonight and tomorrow morning. So not just wet. Not just potentially a month's worth
04:31of rain falling in a day or so. But also very gusty winds as we go through the
04:36course of tonight and into tomorrow. So yeah stays very windy throughout
04:40Wednesday and into Wednesday night. That low gradually then spills its way further
04:45north. Further circulation has developed because the jet stream is still in that
04:49area. Still helping to develop low pressure systems. So yeah pretty wet week
04:54across Spain and Portugal and it has been a pretty wet month all in all as
04:59well. Eventually you'll notice as we run through the rest of this week that that
05:04low pressure system is just starting to creep further north and creep
05:09towards the UK and that will mix things up for us as we head towards the weekend.
05:15But we'll have more on that in a moment. So yes very wet in Spain and Portugal.
05:19But I said quite a big international flavor to this week's deep dive because
05:24now we're heading over to the United States. But not just me talking about
05:29this because earlier on I had a chat with Deputy Chief Meteorologist Dan
05:33Holly. He popped in to talk about what's been happening in the United States
05:37severe weather outbreak over the weekend when he was actually on shift. So
05:42earlier on I had a chat with Dan Holly. Dan thank you very much for joining us
05:47here. This is your first deep dive. It is it's nice to be here. Do you want to tell
05:50everyone what your role is here at the Met Office and where people may have
05:53seen you before. Yes so I'm a Deputy Chief Meteorologist here working in the
05:57expert weather hub and we look at UK and global weather. Hence we're here talking
06:01about global weather here. My previous job well I did a variety of things but
06:05one of my roles was as a weather presenter for BBC Look East. So some of
06:09our viewers may recognize me back in the day on TV in the East of England. Yeah
06:13it's great to have you back on camera as a first time on the deep dive. First of
06:17many hopefully. Now you were working over the weekend and we're here to talk about
06:22what happens stateside some pretty serious weather. Yeah it certainly was a
06:26busy weekend. If we start off by looking at the bigger picture then as to what
06:31was happening because we had a variety of hazards a multi hazard event. We quite
06:34often use the term multi hazard in the UK but I think this takes it to a whole
06:38new level doesn't it. So essentially on Friday we had this area of low pressure
06:42tracking across the southern portions of the plains. This is for early Saturday so
06:47by this stage it's moved up towards the northern plains. And this brought very
06:50strong winds with blowing dust, wildfires, power cuts that sort of thing across the
06:56southern plains. It also brought a tornado outbreak later in the day on Friday
06:59further east. And then if we run this animation through into Saturday itself
07:03you'll see this second low develops on the trailing cold front. And this brought
07:06another spell of tornadoes across the southern states the Gulf states here. So
07:10these bright colors that's a lot of heavy rain and within that band that's
07:14where we saw the worst the tornadoes. But those strong winds that was the
07:18initial problem across further north. Yeah really tight pressure gradient on
07:23the southern flank. You can see the isobars really squeezing on the southern
07:26flank and you know some of the gusts of wind that we saw within that. Amarillo in
07:30the Texas panhandle so somewhere around here had a gust of 83 miles an hour.
07:35Amarillo has a population roughly the same as Hull so it gives you an idea.
07:40A place I know well. I knew you'd like that stat. So yeah and then a little bit further south in
07:44Lubbock which is in West Texas they had a gust of 81. And I think that's its
07:48strongest gust there since 1976. So unusually strong winds. Yeah.
07:53Obviously causing a lot of power cuts because of the strong winds as well.
07:56And other hazards that we saw. Obviously this is an image that we've got from
08:01OK Weather Watch. What are we seeing here? Yeah. What are we not seeing?
08:06Well exactly. This was taken actually by a friend of mine who lives in Oklahoma and
08:10he chases storms. You know he knows his stuff. Oh wow. He was chasing on
08:14Friday last week and obviously this dust storm developed because of those strong
08:19winds. And you can see the visibility massively drops. You cannot see very much
08:22ahead of you. You can't even see vehicles going the other way on the other side of
08:25the road. So understandably this led to a lot of accidents both in Texas and
08:30Kansas. Sadly led to some fatalities actually with multiple vehicles
08:33colliding in these conditions. And actually if we look at the satellite
08:36sequence you'll see this dust being picked up thanks to these very strong
08:40winds. So again let's orient it. So where are we? Which states which?
08:44So we've got Oklahoma here. Right. That's Texas there. That's the top bit of Texas.
08:48That's right. And then we've got Kansas, Nebraska, Colorado etc. We'll come
08:53on to what else is going on in the satellite sequence in a moment. But just
08:56focusing further south you can see all this sort of dirty brown color here
09:00coming out across Texas up into Oklahoma. That's all that dust being picked up
09:04originating from say New Mexico over here. But they're being transported a
09:08long way northwards. Hundreds if not thousands of miles across there. Yeah. I did a very
09:13quick calculation on Friday evening actually looking at how much of this
09:16area was covered by dust at any one time. And it was larger than the UK. Wow.
09:20It's just mind-boggling that that many parts of the US were covered by dust.
09:24Very poor air quality as you can imagine with all of this blowing around as well.
09:28So you can see that that's the low there. That's the second one that developed and
09:32it just picked up those winds. And what are these these little crosses on here
09:35that we're seeing? They're lightning flashes right? They are indeed yes. You
09:38can see the thunderstorms erupting on what is effectively a dry line. The US
09:42is quite unique actually. It has a synoptic feature called a dry line which
09:46you don't tend to find in many parts of the world. And that's essentially a
09:49boundary between very warm moist air from the Gulf and much drier air coming
09:53in from the desert southwest. So usually you can't really see very much. You know
09:58in the UK when we get a weather front you see a band of cloud and rain. In the
10:02US you have these boundaries but they're not that visible until you get these
10:05thunderstorms erupting along them. And then suddenly you can see there's
10:08clearly a boundary in here that's working its way through. And that's called a dry line.
10:11Yes. And it's where the moist air hits the drier air. Yeah that's
10:18very common in the US because obviously it's very dry and hot over the desert
10:22southwest. It's like a frontal boundary with the two air masses but it's got a
10:26specific name because it's because it's so well-defined. That's right. Yeah a dry
10:29line, not heard that before. Okay so we've got the dust, we've got the
10:32thunderstorms, what else what else did we see? Always ongoing I guess. It is indeed yes.
10:38So you know we had some significant wildfires in Oklahoma. Some local
10:43meteorologists in the area have described this as the worst wildfire
10:46outbreak they've ever seen in terms of the number of fires on one day. I think
10:50it was something like 130 fires. Around 300 properties have been destroyed just
10:55in the state of Oklahoma. And something like 12 counties had a state of
10:58emergency declared because of the wildfires on Friday. And obviously these
11:02are being fanned by those incredibly strong winds we've already talked about.
11:05The air is very dry. In fact there was one weather station just east of
11:10Oklahoma City that recorded a relative humidity of just 2%. Oh my goodness.
11:14That's how dry the air was on Friday. And on top of that it was 22 degrees. So
11:19hot and dry and incredibly windy as well. So you know perfect conditions for fires.
11:23That's partly because I guess if you go back to the satellite that the winds, the
11:27lows coming here, the winds and the Rockies. You've got the Rockies here
11:30right. So the air is coming over the Rockies and drying out as it
11:34descends. Yes and obviously a very dry source down in the desert southwest as
11:37well. So yeah incredibly dry air and you know that's what fires need really. And
11:43they spread so quickly during the course of Friday. And sadly a lot of people have
11:47lost their homes because of this in Oklahoma. And it's really ongoing.
11:50There's still many of these fires still burning. I mean when you've got very
11:54strong winds obviously it's very hard to contain the fires. But you need to
11:58evacuate people who are in the path of the fires as well. Now in fact if we go
12:02back to the satellite picture there's some little nuances you can pick out in
12:05the wind direction. So down here across Oklahoma we've got a southwesterly wind.
12:09This is actually a smoke plume just here. So southwesterly wind. So initially the
12:15fires are moving in one direction. But if you get a weak front coming through
12:19which we see. You see this plume here coming down from the northwest. That's a
12:23sudden change in wind direction. And so it's a real challenge for firefighters
12:27to keep on top of that sudden shift in wind because suddenly the fire will move
12:31in a different direction. So yeah a really difficult day. And obviously
12:34because it's so windy you can't get aircraft up to try and put water down as
12:39well until the winds calm down later in the day. So for many reasons it was a
12:41really difficult day to get on top of. Incidentally these black dots you just
12:46saw briefly there. They'll come back on the infrared. They are the
12:49wildfires. They become more visible on the infrared. So this is the visible. So
12:53this is visible. And then when sun sets then you can see those black patches in
12:56there on the infrared. That's actual fires burning. Yeah that's right. Incredible how
13:00many they are and how big they are as well. Yeah that's I mean that is huge. I
13:04mean that's Texas is what 20 times the size of the UK or something isn't it?
13:10They are absolutely vast. And yeah you can see some smoke plumes coming in here.
13:15So much you can see from one satellite picture. Yeah I just thought this was a
13:18stunning picture because there's so much going on. So much going on. Yeah just on
13:21Friday. Must have been a fun night shift just watching all this
13:25develop whilst at the same time being terrifying. Part of our job. We
13:29haven't even touched on the tornadoes. So shall we look at those? Oh no we've
13:32got more. Yes we've got one more to show. The wildfires. What's this? Well this was
13:36a bit of an odd sort of event really. So a wildfire went past this weather
13:40station in Oklahoma and briefly it recorded a temperature. It says here 173
13:46Fahrenheit which is I think about 78 Celsius. Wow. And then it went offline
13:51unsurprisingly. And you can see from from the pictures. Yeah we can we can
13:54actually hopefully have a little zoom in on that. You can see. So this is this is
13:58kit that's just been melted by the wildfires. I mean it shows up pretty well
14:01doesn't it? Yeah. It's all warped and stuff so. Incredible. They will have to
14:05obviously replace those instruments. But yeah incredible to see that it recorded
14:09temperatures near 80 Celsius as the wildfire went through. As the wildfire went through.
14:13Unbelievable. And yes there was also tornadoes. Yeah so we saw those
14:19thunderstorms erupting on the satellite sequence. We had two waves of tornadoes.
14:23One on Friday evening. Those were a bit further north across the midwest
14:27area. And then these ones these pictures we've got here are from Mississippi on
14:31Saturday. Right. Three tornadoes have been rated EF4 which is. The scale goes
14:37from. Zero to five. Zero to five. One of them has been estimated wind speeds of 190
14:43miles an hour. Top end EF4. They're still investigating. It takes days if not weeks
14:47especially when you get so many. We had something like 90 tornadoes I think from
14:52from this event that we know of so far. So after an event usually meteorologists
14:57from the National Weather Service will go out and look at the damage and try
15:00and plot the path of these things. And try and work out the strength. And they
15:06have to bear in mind not all properties are built particularly well. So you know
15:10you could look at a flattened house and think oh that looks devastating. But
15:12actually the house may be may have been poorly constructed. Some houses aren't
15:16even anchored into the ground in some cases. So it's quite hard then to
15:20retrospectively have to know what the foundations were before you can work out
15:24how strong the winds are. So it takes time obviously to try and work out where this
15:29sits on the scale of winds. But at the moment 190 is the highest I've seen so
15:34far. Another one here which is yeah again hard to tell how far away that is. But it
15:39looks like it looks a very wide. Yes. You can certainly see the left-hand edge somewhere around here and the right-hand edge is there.
15:45This picture kind of captures it fairly well actually because a lot of the
15:49tornadoes this time of year tend to be in the Gulf states further south where
15:53it's very humid. The cloud base is very low. They often get rain wrapped. And as
15:57you can see there are a lot of trees and hills in this part of the world. A lot of
16:00pine trees. So getting a visible view of the tornado is very difficult and very
16:06hard to sort of chase them if you like because they tend to move through very
16:08quickly as well. And sadly you know the population is denser in the southern
16:13states. And also because you're near the Gulf you've got this plentiful moisture
16:17all day long. So it's not as dependent on the sort of sunshine heating the ground
16:21that you would see elsewhere in the US. Right. So you can get tornadoes any time
16:24of the day in the south. Whereas the further north you go they tend to be
16:27more sort of late afternoon or the evening time. So this these can kill
16:31quite a few people at night especially because you can't see them coming. Yeah
16:35nighttime tornadoes are way more dangerous aren't they? Yes. And they are.
16:38There's indications that nighttime tornadoes are becoming more
16:41frequent as well with with climate change. Yeah. Very interesting stuff and
16:46there's just one more picture here to show you the devastation. Yeah. I mean you
16:51know there's only so many words you can say about this really. It kind of speaks
16:54for itself just how devastating some of these things can be. And how communities
16:59can be just you know completely destroyed in a matter of less than a
17:02minute. Yeah. Yes. Absolutely devastating scenes there. And you know the
17:08potential for more severe weather in the United States over the rest of this
17:12week. If we take a look at what is happening over there now and see it's
17:19it's not the same kind of setup. But it's similar in a low pressure in a
17:22similar kind of place at the moment. And if we play through that. So this is the
17:26jet stream. There's a low pressure here. But actually the jet kind of intensifies
17:30this this limb of the of the a new low kind of spawns out of it because of the
17:35because of the flow over the Rockies. Yeah that's right. I mean this is late
17:38later on today. And again you can see the isobars squeezing together. As we've
17:43already said the wildfires are still ongoing in some areas. And we're probably
17:46going to see more today because the winds are going to be picking up again.
17:49Very dry air once again coming in from the desert southwest. So parts of the
17:53southern plains today are under alert for wildfires. Are they? Yes. For Tuesday.
17:59Yeah. And as this low continues to trundle northeast we might get some
18:03severe weather severe thunderstorms up in towards the Midwest and the Great
18:06Lakes. Not to the extent that we saw at the weekend. But another wave of
18:10thunderstorms with that. And possibly more once we get to the weekend as well.
18:14You can see that. Yeah. As the low of those isobars really squeezing together.
18:17So that wind just picking up. And again just drawing in the dry air from over
18:22the Rockies. It's all to do you know that they talk about tornado alley. And it's
18:27it's just because of the setup of the United States and the way the land is. We
18:31don't actually take everything off. We can maybe look at the states and just
18:35see how how that works. Because you've got you've got the Rockies here. So they've
18:40got the air coming over the Rockies which is very dry. And you get the the air
18:44coming up from from the Gulf of Mexico. And it's where they combine. Yeah. It's a
18:48very unique setup that allows repeated episodes of these severe thunderstorms
18:53every year really. And what you tend to find is very hot air over the higher
18:58terrain in the southwest not necessarily over the Rockies but it's higher ground
19:01right here. That comes out across very moist air at low levels and acts as a lid
19:06initially called a cap. And then you get an upper trough in the jet stream coming
19:10in and that tends to release the energy that's been building up under that cap
19:14as you get the sort of daytime heating going on and you get these thunderstorms.
19:17So this is kind of the beginning of the storm season. I mean you can get
19:20tornadoes any time of the year if you've got the right ingredients. But the
19:22ingredients come together much more frequently when you get into sort of
19:25March April May onwards. So you've got that warm moist air at low levels. You've
19:29got that air higher higher up in the atmosphere and warm air obviously wants
19:34to rise and it tries to rise and it just it's capped initially but then pop it
19:39goes. And that's where the expression loaded gun comes from. Exactly. The
19:42atmosphere is like a loaded gun. You hear that quite a lot from from the States
19:45and then bang it just goes and and you get the thunderstorms as we've seen. And
19:50we can show you the how it changes through through the year. So what are we
19:55looking at here? Yeah so these plots from the Storm Prediction Centre and it's
19:59looking at historical events and the probability of a tornado within a 25
20:04kilometre radius. Worth noting that the numbers on the scale here are incredibly
20:08small. Yes. Yeah you might not be able to read that but the whites like 0.1% and
20:13this this kind of mid red is 1%. So you know anywhere it's a very low
20:19probability of getting a tornado. But what we can see here this is for the mid
20:23of mid-March and then we've got mid-April up here mid-May mid-June just to show
20:27the progression through the spring and early summer. And you can see you know
20:30the probabilities at this time of year are mainly in the Gulf States where we
20:33saw most of the tornadoes over the weekend. And then as we go deeper into
20:37the season and the jet stream starts to move further north through the spring
20:41and summer we see that focus shifting further north while also increasing. We
20:44start to get these darker colours appearing focusing on the central plains
20:48once we get through to sort of mid-May. And then once we get into June it starts
20:52moving a bit further north and by July actually the risk starts expanding up
20:56into Canada as well. So Canada can get its fair share of supercells and
20:59thunderstorms. But more likely later in the summer. Yeah exactly. In the summer
21:03rather than the spring which is you know people always associate May with
21:07like the peak of the tornado season. And it is shifting again with climate
21:11change the suggestion that it's getting earlier or the start of the season is
21:15getting earlier as well as those increasing chance of seeing them more.
21:19We're seeing you know temperatures in the UK like 20 degree thresholds getting
21:23reached earlier on average as our climate continues to warm as well. What's
21:28particularly unique if we quickly go back to the satellite animation for this
21:32part of the the world anyway. We zoom in on what's going on down in the Gulf
21:38States in particular and just sort of concentrate on what the clouds are doing
21:42in the low levels down here. Should be playing through. There we go. So if we
21:47focus on what the clouds are doing over say Alabama, Mississippi etc. At low
21:51levels we've got these small cumuliform clouds which are forming. See the streets
21:55the cloud streaks there. Yeah I mean a classic sort of fair weather cloud
21:58bubbling up. But if you watch their motion they're running south to north
22:02streaming in from the Gulf. So that's indicative at low levels of all this
22:05warm moist air coming in from the Gulf and streaming further north into the US.
22:08But what we also notice if you look a little bit higher up if you like you can
22:12see this sort of wispy cirrus cloud every now and again there's a band of it
22:15here. And that's running from west to east. So just by looking at the satellite
22:19picture you can already tell the winds are doing different things at different
22:22levels. And this obviously tells you there's a lot of what's called wind
22:25shear where the wind changes direction or speed as you go up through the
22:28atmosphere. And that's the kind of ingredients you need along with the
22:31instability to generate these rotating thunderstorms that produce. Low levels
22:36of winds coming from the Gulf. Higher up they're coming in from from the west and
22:39it's that combination that shift. And yes that's so clear on that satellite.
22:44It's absolutely fascinating stuff. Now the thunderstorms breaking out. All the
22:47lightning strikes associated with them as well. Yeah yeah absolutely. I could watch that loop for hours.
22:52So much going on. It's just incredible.
22:56Well it's a small part of the United States but it's actually quite a large part of the states.
23:02Dan thank you so much for coming in. Absolutely fascinating to have you on.
23:06Really really insightful stuff there on the severe weather in the
23:11United States. Obviously you know serious weather ongoing and will continue to go
23:15on. And the team upstairs the operational meteorologists and the guidance unit
23:19will be continuing to look at this over the next few days and we'll continue to have updates.
23:24But thank you so much for coming in and offering your insight and thank you to
23:27your getting all that imagery from your friend. Hope you stay safe over in the United States.
23:31He's very busy at the moment. I bet he is. Yeah. Busiest time of the year.
23:35Yes definitely. Dan thank you so much for coming in and please do come back again sometime.
23:39Yeah pleasure. Thank you. Great to have Dan pop into the deep dive earlier.
23:43Do let us know if you enjoy that kind of stuff. Really insightful I thought.
23:47So let us know in the comments if you like the international flavor to these deep dives or say any other suggestions.
23:53Please do hit the like and the subscribe button if you're not already subscribed to our channel.
23:58But I'm sure you already are because you're a proper met head because you're this far into the deep dive.
24:02So thank you again for being there. We really do appreciate it.
24:05OK. We've covered Spain Portugal. We've covered North America.
24:08Let's focus a little bit on the United Kingdom because it is a pretty interesting week of weather.
24:14Especially if you like spring sunshine. I mentioned earlier a glorious blue sky day for the vast majority on Tuesday.
24:20All thanks to this area of high pressure. But we are in for a change.
24:24Slow and subtle changes over the rest of this week. The highest slinking away down to the south.
24:31The jet stream is still here anchoring these areas of low pressure pushing them in towards Portugal.
24:37It kind of almost gets cut off kind of almost circulates back in on itself like an oxbow lake there for a time during Wednesday.
24:45But it doesn't quite fully get into that circulation. It actually then reorientates itself later this week into more of a more of a trough.
24:54And what we start to see is this low pressure system developing push northwards by the jet stream slowly but surely encroaching up towards the United Kingdom.
25:04So if you put the satellite picture back on and go through this sequence again you can see the storms developing across Spain and Portugal.
25:13As we went through the course of the weekend a few heavy showers here this next weather system coming in that's that's with us now.
25:19But the cloud that's stuck in here from this circulation is going to get pushed northwards earlier.
25:25So back to the here and now at time of recording Tuesday this cloud is going to drift further north.
25:31So while it's been clear for the vast majority today we are going to see more clouds spilling north.
25:36But we're still being influenced by the high pressure system at the moment and will continue to do so through Wednesday and Thursday.
25:44By the time we get to Thursday the high has moved down here. The low is still here which means the winds have switched direction.
25:51So take the jet stream off. Let's look at the winds at the surface coming in from the east.
25:58At the moment or for most of this week they've been coming in from the east tapping into some cool air still quite chilly over northern Europe as you'd expect at this time of year.
26:07So we've been drawing in cooler air. But as the high slinks south we cut off that colder air.
26:14And gradually the winds start to switch direction so that by Wednesday and Thursday we see the winds are now coming up more from the from the southeast.
26:24So that is going to draw in warmer air from down here. So we are going to get things warming up a little bit both by day and by night eventually.
26:33So it is going to turn warmer. Thursday is probably going to be the peak of the warmth and we could reach 20 degrees Celsius.
26:38Let's look at the temperatures over the next few days. Well let's generally look at the weather pattern of the next few days.
26:44So there's the high slinking away. We've got the easterly wind at the moment which is why it's pretty chilly still on the east coast right now.
26:50Wednesday we go forward. We see a bit more cloud spilling in the winds still coming in from the south generally pushing up there across the northeast of Scotland.
27:01So anywhere where there's a breeze still coming in from the coast still going to be on the chilly side.
27:05But by the time we get to Thursday there's more cloud spilling in and might just be able to make out a few dots of showers as the low is getting closer.
27:13The air is destabilizing a little bit. Some of that cloud shearing ahead from Spain and Portugal.
27:18So yeah generally turning a little cloudier but still for the vast majority Wednesday Thursday nice days hazy sunshine only a very small chance of seeing a shower.
27:27But look at the temperatures by the time we get to Thursday we're up to 14 15 16 degrees at least.
27:33And I reckon we could easily get up to 80 90 maybe 20 degrees Celsius.
27:37That's looking at the temperatures overnight now and we'll see those rising quite a bit.
27:44So while it will be cold tonight with the clear skies could get down to minus six or minus seven.
27:49By the time we're getting into Thursday night Friday night the winds coming up from the southeast.
27:54So although there'll be still quite a bit of clear skies those temperatures will be ticking up quite a bit over the next few days.
28:00So yeah temperatures gradually rising still cold on the east coast today.
28:05Even here turning milder there Thursday's temperatures are set 16 17 18 easily.
28:10We could easily peak at 20 degrees somewhere across the southeast in this area as is typical.
28:16By the time we get to Friday there's a big question mark. So we are going to see a change.
28:20The weather patterns are shifting as that low gets closer to us.
28:24But the timing of it there's quite a bit of uncertainty more so than usual.
28:29Let me show you what the Met Office computer model is expecting.
28:33This is the rainfall building up over the next few days dry dry pretty dry small chance of a shower.
28:39But by the time we get to Friday well much more in the way of rain covering the UK.
28:44But how likely is that. Well let's put the rainfall off just take that off and go through by the time we get to Friday.
28:55This is what the Met Office model wants to do. So it's pushing up a lot of rain through Friday morning.
29:02That band of rain coming up some pretty heavy bursts in that as well and extending all the way up to the Western Isles of Scotland on that.
29:09And then it just gets wetter as we go through the weekend and actually developing quite a nasty looking area of low pressure across the UK on Sunday.
29:18So that is moving northwards. That would suggest some quite heavy rain.
29:22But if you look at other computer models they're not really in agreement with this.
29:26And I can show you a couple of examples of that.
29:28So this is the EC the European model courtesy of windy dot com.
29:33That's where the European model has the rain on Friday.
29:36So yeah it's in a similar position across Wales southwestern but it's not as intense and it certainly isn't as extensive further north across western parts of Scotland.
29:45So that's a clue that our model is perhaps overdoing it.
29:49And if we look at GFS the American model at lower resolution but it has the same weather pattern in that low is gradually edging its way northwards.
29:58But by now on this model on the American model the GFS model.
30:02Well there's only a bit of rain really across Devon and Cornwall most of it's in southern parts of Ireland.
30:07Wales is largely dry and certainly western Scotland is dry and fine.
30:10And one more example icon the German model which again has a similar set up.
30:15So all of these are agreeing all these computer models are agreeing about the weather pattern with the low heading up from Spain Portugal being in the southwest.
30:23But look at that that's completely dry across the UK midday on Friday.
30:27So there is a fair bit of uncertainty about what will happen as we go through Friday and into the weekend.
30:33But all the models are agreeing that low is approaching and we will see some wet weather moving its way northwards by the time we get to Friday as that low then comes in spreads northwards.
30:44But the detail of where we see the rain how much rain we see.
30:48Well that's open to a bit of doubt.
30:49It is going to gradually get wetter through the course of the weekend.
30:52But if you've got plans particularly on Friday I suspect large parts of central and eastern Britain will still be fine and dry on Friday.
30:59But it is going to turn more showery from the southwest.
31:02How heavy that rain is and how intense that low is I say open to a bit of doubt.
31:06But we think that the UK model our model is overdoing it at the moment.
31:11If you want more details on that if you do have plans for this weekend then I suggest you subscribe and then you won't miss tomorrow's 10 day trend should be a good one with aid.
31:19So Aidan will be recording that on Wednesday.
31:20That'll be available on Wednesday afternoon that will have more details about the uncertainty why there's uncertainty and what we can expect into the weekend.
31:28But generally speaking if you like it fine and sunny enjoy the next couple of days because it is going to change as we head into the course of the weekend.
31:36We are going to see things turning wetter and well perhaps we could do with that because it has been a very dry month so far.
31:45A quick look at the stats.
31:46We are just beyond halfway through March and this is the accumulation of the rainfall through the month averaged across the whole of the UK.
31:57And that is quite stark.
31:58That is a very dry month.
32:00So this black line through the middle that's the average well over 100 years worth of data.
32:06That's the wettest March on record that red line at the top the driest March on record this blue line at the bottom.
32:13And these grey shaded areas representing 90 percent and 95 percent.
32:17And you can just about make out where we are now in this current month.
32:20March 2025 is in that bottom 5 percent or top 5 percent in terms of driest bottom 5 percent in terms of rainfall.
32:28Depends which way you look at it.
32:29But yeah in the in the most extreme 5 percent in terms of how dry it has been so far that is going to change as we see wetter weather coming in.
32:39Not really that useful to look at the stats halfway through a month always.
32:43But that is so stark that I thought I would show it because it is really quite interesting.
32:48It has been a very dry March.
32:50Main reason for that just high pressure position the jet stream we've had higher pressure across parts of the south that start the month.
32:56We're expecting perhaps a bit more in the way of westerly winds to bring a bit more in the way wetter weather.
33:00But one of the reasons for that is perhaps not happening is because La Nina has weakened.
33:05We were expecting La Nina has been a very weak La Nina and now it's weakened further.
33:09La Nina at the end of winter can generate or is associated with more westerly winds and wetter weather for the UK.
33:16But that's we haven't seen that.
33:18So one of the reasons behind that suggestion could be that weakened La Nina is part of it.
33:24We also had an SSW sudden stratospheric warming the weekend before last.
33:29That also promotes blocking weather patterns and slow moving weather patterns like we've seen.
33:33But that takes at least a week or so to come down through the atmosphere.
33:37So we're not really seeing the effects of that.
33:39But it does suggest that we could see continued patterns like this for the rest of the month.
33:44So, yeah, plenty to get our teeth into, even though it has been a very dry month.
33:49But there's also some regional variations and just backing up that high pressure has been dominant across the south.
33:55This is the map of the UK as a whole.
33:57Now, bear in mind, key point to factor out, this is compared to the average for the whole month.
34:05So you would expect it to be drier than average at this stage because we're only 70 up to yesterday.
34:10So the 17 days in.
34:11So we're just over halfway.
34:12So you'd expect you would normally expect at this time in the month 55 percent of average.
34:19And that is this first shade of brown here between 50 and 75.
34:24And there are pockets across northern Scotland that are in that bracket because it has been wetter here.
34:31So much closer to average across northern Scotland because generally higher pressure has been hanging on across the south.
34:37And we've had spells of wet weather.
34:38And we've also had northerly winds bringing some showers down into this part of the world,
34:42which is why also parts of what North Yorkshire are much closer to average.
34:46But generally speaking, we've had higher pressure.
34:48There's blocked weather patterns, which is one of the reasons why it has been a very dry March so far.
34:54And another way of looking at that is looking at the temperatures.
34:57These are the minimum temperatures.
34:59I thought I'd show this because it was nice.
35:02Someone suggested it looked like the French flag, which it does if you go like that.
35:05If you look at it normally, it looks more like the Dutch flag, to be fair.
35:09Or if you're of a certain age, it looks a bit more like Neapolitan ice cream.
35:12It's gone a bit mouldy.
35:13But, yeah, minimum temperatures showing that the northern parts of the UK well above average so far this month when compared to the to the average,
35:22whereas in the south it has been a lot colder and again suggesting we've had higher pressure here,
35:26clearer skies at night, allowing those temperatures to fall away.
35:30Low pressure systems and rain bands drifting across the north, keeping the keeping the cloudier skies,
35:34the windier conditions, which helps to keep those minimum temperatures up at night.
35:38So quite interesting stats so far through this month.
35:42Again, one to keep an eye on through the rest of the month because, yeah,
35:46we are looking at some wetter weather into the weekend.
35:48But beyond that, well, it's likely to be quite a static weather pattern, whether that's high pressure or low pressure.
35:54The jury is out.
35:56But we are looking potentially at quite static weather patterns for the rest of the month.
36:01One more thing to show you on this week's deep dive.
36:04This is dust, dust spreading north from Sahara.
36:09This is for Friday.
36:11Again, one of our deputy chief meteorologists pointed this out to me, dust plume heading its way up from the Sahara.
36:19So the potential on Friday for levels of dust across parts of southern Britain, parts of South Wales,
36:26southern England in particular.
36:28And actually, if you look at the cross section through that, the levels of dust actually quite low in the atmosphere.
36:33So this is a cross section through the atmosphere around two to three degrees west.
36:41And if we play through that with a little bit of a zoom in on it, it's a little bit clearer.
36:45But that those yellow higher concentrations between about nine hundred and fifty and eight hundred hectopascal.
36:50So what's that? Between about five hundred metres and two kilometres up.
36:55So it's quite low. This isn't quite high in the sky.
36:57It's quite low in the sky.
36:59This this dust plume that's heading its way northwards.
37:02And you can tell the low pressures in here and it's drawing up ahead of it.
37:07Those southerly winds, which is bringing the dust, those strong winds,
37:10because it's quite an intense area of low pressure could draw quite a bit of dust.
37:14So it might make sunsets a little hazier, a little bit more spectacular towards the end of the week.
37:19So that's something to keep an eye on. This is for Friday.
37:22Don't forget. Excellence.
37:25Well, plenty going on then in this week's deep dive.
37:28I hope you enjoyed it. Please do keep those comments coming.
37:32Let us know which bit you like, which bit you don't like.
37:34Any other suggestions for any other content that you'd like us to contemplate?
37:39As I mentioned, Aidan's deep dive.
37:42No, Aidan's 10 day trend tomorrow.
37:44This was the deep dive. Aidan's 10 day trend tomorrow should be a good one.
37:48Don't forget to tune in to the Weather Studio live this Friday.
37:51It's Aidan and me doing it this week.
37:53So, yeah, be a good quiz on that.
37:55That's a Friday at 12.15.
37:58Don't forget the sunscreen.
38:00If you're sensitive, UV levels at the moment are about three or four.
38:03And I made a video about UV and we posted that at the weekend.
38:07So we'll put that in the chat as well.
38:09So you can check out that and find out a little bit more about UV,
38:11because it's as strong now, the sun, as it is towards the end of September.
38:15So, yeah, something to to be aware of, even though it is nice and sunny.
38:20Something else to be aware of is the equinox on Thursday at one minute past nine.
38:25So after that, however you measure it, spring has started.
38:30OK, that's it for me.
38:31Thank you very much for watching this week's deep dive.
38:34I'll see you again soon.