0:00:03 > 0:00:06Hello there. Yesterday, Nick Miller was explaining the reasons behind
0:00:06 > 0:00:08this extraordinary spell of weather we're having.
0:00:08 > 0:00:10The answer lies in the jet stream.
0:00:10 > 0:00:13I'm going to continue that theme of the jet stream in this broadcast.
0:00:13 > 0:00:15We're going to see some big changes.
0:00:15 > 0:00:18This week, so far, of course, 30 degrees quite widely across
0:00:18 > 0:00:19England and Wales in particular,
0:00:19 > 0:00:22record-breaking temperatures for the time of year,
0:00:22 > 0:00:25and the reason is a huge kink in the jet stream, initially down
0:00:25 > 0:00:29across the Bay of Biscay and then northwards up towards Scandinavia,
0:00:29 > 0:00:31allowing this influx of hot air from the near Continent.
0:00:31 > 0:00:33Fast-forward to next week,
0:00:33 > 0:00:35a completely different complexion to the jet stream,
0:00:35 > 0:00:39a westerly jet, allowing an Atlantic influence of weather, and
0:00:39 > 0:00:42that means things kind of getting back to normal, as we'll see.
0:00:42 > 0:00:45I'll talk more about the jet stream later on.
0:00:45 > 0:00:48But a steamy start to Thursday, the last really warm day, particularly
0:00:48 > 0:00:50where you start off with sunshine across southern counties.
0:00:50 > 0:00:52It could be a slow start further north,
0:00:52 > 0:00:54but the low cloud will break up, the sun will come out,
0:00:54 > 0:00:57the temperatures will shoot up, widely up into the twenties,
0:00:57 > 0:01:00possibly the low thirties across the south-east.
0:01:00 > 0:01:01Then it all goes bang, potentially,
0:01:01 > 0:01:03during the course of Thursday evening and night,
0:01:03 > 0:01:06initially across southern counties of England,
0:01:06 > 0:01:08up through parts of Wales, the Midlands, northern England.
0:01:08 > 0:01:11Some torrential thunderstorms possible. Warnings have been issued.
0:01:11 > 0:01:14It could turn very wet across eastern Scotland, too.
0:01:14 > 0:01:17In fact, this rain lingering across eastern areas well on into
0:01:17 > 0:01:20Friday, we think, before eventually it brightens up from the west.
0:01:20 > 0:01:24Much, much fresher conditions coming in off the Atlantic, temperatures
0:01:24 > 0:01:25in some places ten degrees lower
0:01:25 > 0:01:28on Friday compared with Thursday. You'll notice the difference.
0:01:28 > 0:01:32That front eases away later on Friday and into Saturday.
0:01:32 > 0:01:34We see a ridge of high pressure building in.
0:01:34 > 0:01:39Saturday is looking good for most of us. There'll be some sunshine.
0:01:39 > 0:01:41The vast majority of us will be dry, we think,
0:01:41 > 0:01:44with broken cloud, and the winds shouldn't be too strong,
0:01:44 > 0:01:46and temperatures kind of back to where they should be
0:01:46 > 0:01:48at this time of year, mid to high teens,
0:01:48 > 0:01:50possibly low twenties across the south-east.
0:01:50 > 0:01:52A developing area of low pressure,
0:01:52 > 0:01:55quite an intense feature, heading up towards Iceland,
0:01:55 > 0:01:57and this trailing weather front on Sunday will bring some rain
0:01:57 > 0:02:00initially to Northern Ireland and Scotland,
0:02:00 > 0:02:02and then it's going to start to head south-eastwards.
0:02:02 > 0:02:04Some uncertainty about its progress, though,
0:02:04 > 0:02:06so it could stay fine across many southern and eastern areas
0:02:06 > 0:02:08right the way through the day.
0:02:08 > 0:02:10And it will brighten up behind that weather front, as well.
0:02:10 > 0:02:14That front could linger across more southern and eastern areas
0:02:14 > 0:02:15on Monday, so watch this space.
0:02:15 > 0:02:18A lot of uncertainty, but some showery rain, potentially,
0:02:18 > 0:02:19across the south-east.
0:02:19 > 0:02:22Brightest the further north and west we go on Monday.
0:02:22 > 0:02:26Now, let's take a step back, because to look further ahead we have to
0:02:26 > 0:02:28look further afield sometimes.
0:02:28 > 0:02:31The Arctic is beginning to cool quite quickly now,
0:02:31 > 0:02:34little lobes of blue beginning to head their way down across
0:02:34 > 0:02:39Canada and Greenland, so colder air heading into the Atlantic
0:02:39 > 0:02:42meeting warm air still trying to come up from the tropics,
0:02:42 > 0:02:44and where the two converge,
0:02:44 > 0:02:48we tend to get a supercharged jet stream, and that's exactly
0:02:48 > 0:02:50what's going to happen during the course of next week.
0:02:50 > 0:02:53So, a strengthening westerly jet stream,
0:02:53 > 0:02:56and that's going to start to power its way towards us and carry
0:02:56 > 0:02:58weather systems with it,
0:02:58 > 0:03:01and that means that we're fairly confident that next week
0:03:01 > 0:03:05we're going to see some outbreaks of rain, some gusty winds, too, on
0:03:05 > 0:03:08that jet stream, particularly across more northern and western areas.
0:03:08 > 0:03:12However, Europe is quite warm, and we have to keep an eye on that,
0:03:12 > 0:03:15because if the winds start to come up from the south again,
0:03:15 > 0:03:17we could see some of that warm air returning.
0:03:17 > 0:03:21We're keeping an eye on it. But in general next week, back to normal,
0:03:21 > 0:03:24that Atlantic influence, wettest across the north-west, but just
0:03:24 > 0:03:26that caveat - we could still see
0:03:26 > 0:03:29some warmth across the south-east. I will update you again tomorrow.
0:03:32 > 0:03:34THEME PLAYS: The Apprentice