00:00Hello. A little bit of warmth, a fair bit of rain, and a sprinkling of uncertainty.
00:06Well, if it isn't a classic Met Office 10-day trend, and this one will take us through the first full week of meteorological summer.
00:14Meteorological spring, the months of March, April and May, has been remarkable.
00:18Incredibly dry, pretty warm, and the sunniest on record.
00:22And the reason for that was the position of the jet stream.
00:25Generally, it's been way up to the north, but it's shifted now. It has sunk back further south, and as a result, the weather's changed.
00:32It's been pushing low-pressure systems our way. This one brought the rain through the course of the weekend.
00:36And eyes focused on this one now as it heads towards us for Thursday.
00:41Now, it is kind of sitting in the middle of the jet stream here, so that's just pushing it along.
00:45If it was a little further north, it would intensify a bit more and perhaps bring some livelier winds.
00:50But it wouldn't take much to shift that, and that is where the uncertainty lies.
00:55Certainly in the short term, more uncertainty than usual.
00:58Just how the low develops and whether another low actually follows on behind.
01:02Now, this is the Met Office model, and the jet just pushes that low pretty much out of the way by the time we get to Friday morning.
01:08And a little ridge of high pressure builds in behind, bringing a few showers to Scotland,
01:12but generally turning things drier here during Friday.
01:16If we take a look at the European model for the same time, first thing on Friday morning,
01:20well, the low has cleared away, but it's actually developed another low in here,
01:24and that's keeping things pretty wet across Scotland.
01:26The rain is slower to clear as a result, and the ridge of high pressure is further behind.
01:31Now, as I say, quite a bit of uncertainty in the short term, and that is fairly unusual.
01:37In fact, it's one of those slightly counterintuitive situations
01:40where we have more confidence in the forecast for the weekend than in the shorter term,
01:44and that's what this graph is showing here.
01:46It's like a confidence-o-meter, if you like.
01:48The average line is this one here going from 1% or 100%,
01:52and it tends to drift and dip down as you get further ahead in time.
01:59And the actual hash line, well, that's the confidence in the current forecast,
02:02and anything red is below the average, green is above the average.
02:06You can see here that in the short term, the next 36 hours,
02:09the confidence in the forecast is below average, and it actually goes up and is green and above average into the weekend.
02:16So we have, as I say, more confidence in the forecast for the weekend, perhaps, than we do in the shorter term.
02:22What is going to happen at the weekends?
02:24Well, that jet stream remains reasonably active.
02:27It's not, as you may have read in the press, a Caribbean jet stream.
02:31It is coming up from the Atlantic, but it is also allowing the isobars to draw up the air from the southwest.
02:38So these are the winds at the surface, southwesterly winds,
02:42and we may well tap into some real warmth from Iberia as we head into Friday and Saturday.
02:49So temperatures across the south, where it warms up on Friday, could get to 24, 25, maybe even 26 degrees Celsius.
02:56And by the time we get to Saturday, well, that warmth extending further north across more parts of central and eastern England.
03:04So we'll see temperatures more widely over 20 degrees and into the mid-20s across parts of eastern England.
03:10So it is warming up for some, but notice with the winds coming in from the west or the southwest,
03:15these western areas aren't going to be as warm.
03:18It'll still feel quite warm and humid, though, pretty much everywhere as we head towards the end of this week.
03:23But temperatures, as I say, quite a contrast.
03:25It is going to warm up, but only for some.
03:28Another way of looking at that is comparing the temperatures with the average for the middle of May.
03:34You can see above average across east angle in the southeast on Friday, closer to average further north and further west.
03:40And it's a similar pattern on Saturday, but notice those higher than average temperatures becoming more widespread over the Midlands and eastern England for Saturday.
03:47So if we see some sunshine on Saturday, it really will feel quite warm in these eastern areas.
03:52But will we see the sunshine?
03:54Well, certainly not further west, where temperatures will be closer to average.
03:56We are expecting more cloud and more rain from another area of low pressure that'll be heading in.
04:02This initial warm front bringing some showery rain.
04:04Then this weather front swings through.
04:06And then we see another potential area of low pressure developing, bringing showery rain across the country during Sunday.
04:12Notice, though, the wettest conditions, most of the rain always closest to the low pressure and not much rain this weekend getting to parts of the south.
04:22And so we can show that with the rainfall accumulations from the three models that we use most.
04:28The Met Office model behind me, European model in the middle and the American model, the GFS here on this side.
04:35You can see they're all in pretty much agreement.
04:37So this is, again, going back to that confidence in the forecast because the models are all agreeing pretty much about the rainfall pattern for the weekend.
04:45We were pretty happy with the way that the weekend is shaping up.
04:48This is the total rainfall through Saturday and Sunday.
04:52The wettest conditions in western Scotland in each of the models and actually not much rain at all, if any, getting to parts of East Anglia and the southeast.
05:00So, as I said, we're pretty confident about what's going to happen through the weekends.
05:04Showery rain at times, most persistent across the north and the west with parts of the south and east staying largely dry.
05:11What about beyond that?
05:13Well, that area of low pressure bringing the wet weather through the weekend should be pulling away.
05:18And then we've got another little ridge, a little bump in the isobars that may well bring many places a dry day on Monday.
05:25Monday could be the driest day overall as we go through next week.
05:29Still, there's the chance of some showers mixed in on Monday.
05:33But generally, as I say, Monday with this little ridge of high pressure looking a little drier.
05:37But it may well not last because, as you can see behind me, more low pressure systems gathering out in the Atlantic.
05:43And again, if we take a look at the big picture and the winds high up with the jet stream in a slightly different position now, it's starting to dip down more to the south.
05:51And you can see this little dip here.
05:54We call this a trough.
05:55And in here, it's often where we see low pressure systems either developing or just kind of sitting around.
06:00Instead of the jet stream pushing lows through, get a little dip like that, then you can keep low pressure systems kind of becoming slow moving and sitting close to the UK.
06:10That's likely what we'll see after a drier day on Monday, that low moving in and perhaps becoming slow moving close to the UK.
06:18Switch to the European model now and switch the colors.
06:20But it's the same showing the same thing, showing the pressure pattern in black here and the jet stream, those winds high in the sky in yellow and orange.
06:29And you can see it just dipping down, generating that trough and just allowing that low to sit around rather than pushing it along.
06:36So low pressure likely to be close by to the UK through the middle of next week.
06:40This is Tuesday night and into Wednesday.
06:43But the exact position of the low, well, that is open to quite a bit of uncertainty.
06:49As you'd expect, we're talking pretty much a week away.
06:52And this is the Dalmatian plot, the spotty plot that kind of helps to show that this is, again, from the European model.
06:59The previous chart was the main model run.
07:02But we obviously don't just look at one computer model run.
07:05We use an ensemble and run the model many times.
07:07And each of these spots is a representative of where that low pressure system could be sitting.
07:13I've zoomed in here, but it's no clearer.
07:15It's showing that that low could be northern, could be to the north of Scotland or it could be down across the south of England.
07:21So the position of the low next week open to quite a bit of uncertainty.
07:25But it's reasonable to suggest that low pressure is going to be pretty close by to the UK through the middle of next week, Tuesday and Wednesday in particular.
07:34And when low pressure is close by, that means the air is rising, that means we're going to see cloud and showers.
07:40So, yes, looking pretty unsettled through the middle of next week.
07:44And this probability plot, which goes beyond the middle of next week and towards the following weekend and even beyond that,
07:51well, this isn't what you want to see if you're after dry and sunny weather because these dark blues are dominating.
07:57And those dark blues means that the winds will be continuing to come in from the west.
08:02And when the winds come in from the west, come in from the Atlantic.
08:04So they're bringing moisture and plenty of showers, particularly so into western areas.
08:11Now, as we go towards the back end of next week, there's a staggering of the steps, if you like.
08:17And those dark blue colours do tend to dip down a little bit.
08:20So we may start to see a slightly different flavour of weather.
08:23But don't get too excited because those light blues are just kind of southwest of the wind, still low pressure dominant, generally speaking.
08:30But we are likely perhaps to see a hint of a change as we go towards the end of next week.
08:36So the most likely set up is for low pressure close by to the UK on Wednesday, a cyclonic set up with west or southwesterly winds.
08:45And this is showing the rainfall anomaly, so how much more wet than average it's likely to be with those dark blues situated across Wales, northwest England.
08:54So in this set up, which is the most likely pressure set up over a third of the models, suggesting this set up, which would keep the western half of the UK wetter.
09:05But generally, it is going to be wetter than average across the whole of the UK through Wednesday in particular.
09:10Now, by the time we get to the end of the week, signs are that the low pressure, yes, still dominant, still cyclonic with more of a westerly.
09:17But you can see that the wettest conditions are becoming a little more confined to the north.
09:22Notice also the chance has dropped off a little bit.
09:25We're over a week away.
09:27And by the time we get to Friday, again, the most likely pressure pattern actually has low pressure further away to the north.
09:34And signs perhaps of a ridge of high pressure trying to build in from the south.
09:39So hints that perhaps something a bit dry could develop across southern areas in particular through the back end of next week.
09:47But overall, next week looking pretty changeable, to say the least.
09:50The winds continuing to dominate from the west or the southwest, which will keep things reasonably mild,
09:56but also keeping things fairly wet, especially so in western areas.
10:01Complete contrast to the largely easterly conditions we've had for much of spring.
10:05And that hint, which is all it is at this stage, of something a bit drier in the south to end the week.
10:11As always, for those day-to-day details, you want to be keeping up to date with everything from the Met Office.
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