0:00:02 > 0:00:05Hello. You don't hear so much about the jet stream at this time of year.
0:00:05 > 0:00:07That's because it's not as strong as it is in the winter,
0:00:07 > 0:00:09when it thrives off a strong thermal gradient
0:00:09 > 0:00:12between cold air to the north of us and warmer air in the tropics.
0:00:12 > 0:00:14That gradient is there at this time of year, but it is not as strong.
0:00:14 > 0:00:17The jet stream isn't as strong.
0:00:17 > 0:00:18This is how it looks this week,
0:00:18 > 0:00:20it's prone to meandering, not doing very much.
0:00:20 > 0:00:22And look at this, it's splitting this week.
0:00:22 > 0:00:25One portion is going to the north and another is diving to the south.
0:00:25 > 0:00:27This, though, is important.
0:00:27 > 0:00:31This circulation here near Spain, it's a cut-off low-pressure,
0:00:31 > 0:00:33one which isn't moving very much with the flow,
0:00:33 > 0:00:34it's hanging around for a few days.
0:00:34 > 0:00:37But it is going to impact our weather,
0:00:37 > 0:00:40because around it it's going to push warmer, more humid air our way
0:00:40 > 0:00:44with a potential for some thundery downpours later this week,
0:00:44 > 0:00:45as we'll see in just a moment.
0:00:45 > 0:00:47Let's start off, though,
0:00:47 > 0:00:49with how Tuesday's weather is shaping up.
0:00:49 > 0:00:51And we do have a weather front around
0:00:51 > 0:00:53and a weather system bringing some rain to Northern Ireland,
0:00:53 > 0:00:55parts of Scotland and northern England.
0:00:55 > 0:00:59And not just as Tuesday begins, but for much of the day.
0:00:59 > 0:01:02So quite a cool, soggy day for Northern Ireland,
0:01:02 > 0:01:04through southern Scotland, into the Central Belt
0:01:04 > 0:01:06and northern counties of northern England,
0:01:06 > 0:01:08from Lancashire across to North Yorkshire.
0:01:08 > 0:01:11South of that, a few showers, but sunny spells developing.
0:01:11 > 0:01:13Quite a range of temperatures,
0:01:13 > 0:01:15from as high as 25 in central London
0:01:15 > 0:01:18to maybe just 13 degrees if you are in the rainy zone
0:01:18 > 0:01:20here in southern Scotland.
0:01:20 > 0:01:22Now, this weather front is still hanging around for Wednesday,
0:01:22 > 0:01:25but there isn't much in the way of rain left on it.
0:01:25 > 0:01:28Still a lot of cloud in the same areas that saw the rain on Tuesday.
0:01:28 > 0:01:31By Wednesday, maybe some spots of light rain and drizzle,
0:01:31 > 0:01:33but just not as wet.
0:01:33 > 0:01:34Sunny spells in northern Scotland,
0:01:34 > 0:01:38but notice, blue sky and sunshine for more of England and Wales,
0:01:38 > 0:01:40allowing temperatures to edge up further.
0:01:40 > 0:01:43This is the warmth and humidity starting to build.
0:01:43 > 0:01:47And look at that, some spots will be getting close to 30 Celsius
0:01:47 > 0:01:49once again in that sunshine.
0:01:49 > 0:01:52But the area of low pressure, that cut-off low,
0:01:52 > 0:01:54begins to show its hand more by Thursday.
0:01:54 > 0:01:58There is some moisture around that, warmth and humidity,
0:01:58 > 0:02:00and you get some thunderstorms breaking out
0:02:00 > 0:02:03initially towards the south-west of the UK on Thursday
0:02:03 > 0:02:06and then pushing gradually northwards,
0:02:06 > 0:02:08where it is still a bit warmer, just not as warm as it is to the south.
0:02:08 > 0:02:11Although temperatures may be pegged down a little bit
0:02:11 > 0:02:14because there's more cloud around and those storms breaking out.
0:02:14 > 0:02:17That system pulls away to the east during Friday.
0:02:17 > 0:02:19We're in between weather systems on Friday.
0:02:19 > 0:02:20A lot of dry weather around.
0:02:20 > 0:02:23Still a chance of catching a few heavy showers, mind you.
0:02:23 > 0:02:25And there's still some heat to be had,
0:02:25 > 0:02:28particularly across south-eastern parts of the UK.
0:02:28 > 0:02:31But as we go from Friday into the weekend,
0:02:31 > 0:02:34this cold front is important, pushing through.
0:02:34 > 0:02:37And the jet stream becoming a little bit more of a combined feature
0:02:37 > 0:02:40after that split earlier in the week,
0:02:40 > 0:02:42allowing Atlantic air to come through,
0:02:42 > 0:02:45so it's going to be a bit cooler and fresher over the weekend.
0:02:45 > 0:02:47But with low pressure close by, it looks fairly unsettled
0:02:47 > 0:02:50with either some rain or showers around
0:02:50 > 0:02:51and the breeze picking up, as well.
0:02:51 > 0:02:52Now, going into next week,
0:02:52 > 0:02:56it looks like a more typical weather pattern for the summer.
0:02:56 > 0:02:58High pressure, the Azores high
0:02:58 > 0:03:00beginning to build in across southern parts of the UK.
0:03:00 > 0:03:03Low pressure sticking around close to the north-west.
0:03:03 > 0:03:06So a range of weather in this more typical summer pattern
0:03:06 > 0:03:07for the UK into next week.
0:03:07 > 0:03:10And it looks like being, with the position of these pressure systems,
0:03:10 > 0:03:12a north-west/south-east split.
0:03:12 > 0:03:15As a result, parts of Scotland, Northern Ireland, northern England
0:03:15 > 0:03:17will see some of the windiest, wettest weather,
0:03:17 > 0:03:18though it's not going to be a wash-out.
0:03:18 > 0:03:21It's not going to be unsettled all the time.
0:03:21 > 0:03:22But it will be drier and relatively warmer
0:03:22 > 0:03:24across south-eastern parts of the UK.
0:03:24 > 0:03:27But even here, a few weather systems could move through
0:03:27 > 0:03:28from time to time.
0:03:28 > 0:03:29That's how it's looking.