10 Day Trend - What next after the thunderstorms? 12/08/20
Following some exceptionally high temperatures this week, the risk of thunderstorms continues this weekend and the start of next week. What will happen after that. Aidan McGivern has the 10 Day Trend.
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00:00Hello, and welcome to the Met Office 10-day trend. You only have to look at the last 10
00:04days to see how much weather we can experience in the U.K. Ten days ago it was cool and unsettled
00:10and since then we've seen six or seven successive hot days, mainly in the south and southeast
00:16of the country, much cooler further north. But for all areas we're seeing this thundery
00:20breakdown and it's a prolonged thundery breakdown that continues into the weekend and the start
00:25of next week, turning things much cooler gradually by the start of next week. But the
00:32main trend for next week is that low pressure will stick around for most of the week. That
00:38means that the weather will generally be very mixed with certainly some rain for most of
00:44us. Now, let's deal with the thunderstorms first of all because we've seen this plume
00:48of very hot air extend northwards across the country with above average temperatures as
00:53far north as central Scotland, but well above average temperatures for southern parts of
00:58the U.K. Joining that plume of hot air we are also seeing low pressure turn up and the
01:04combination of low pressure and heat is leading to a thundery breakdown and we'll continue
01:09to see those conditions ripe for thunderstorms well into the weekend. One difference by the
01:14time we get to Saturday is that you see the red colours disappearing, it is turning much
01:18cooler and so we lose that heat energy somewhat. So we've still got low pressure nearby but
01:23it relaxes away to the west and high pressure in the north will settle things down only
01:28briefly during Saturday for most of us before the jet stream then starts to get into action
01:34and pushes another low up from the south by Monday. And although it's much cooler, there's
01:40still the risk on Sunday and Monday of some very lively thunderstorms moving up from the
01:46south. So plenty of thunderstorm potential, but potential doesn't necessarily mean everyone's
01:51guaranteed a thunderstorm because they pop up fairly randomly and you can see that on
01:55Thursday afternoon, the main risk area being Wales, central and southern England. You can
01:59see the scattered nature of them as temperatures rise through the day these thunderstorms will
02:04pop up just about anywhere in the south. Further north, Scotland, Northern Ireland, Northern
02:09England largely staying dry, best of any sunshine in the west where it will be quite warm, but
02:14in the east we've got this low cloud creeping and it will be a gloomy kind of day along
02:18these North Sea coasts with a cool breeze as well. But in the south east it's another
02:22hot day, not quite as hot as it has been recently. By Friday, that cloud cover coming in from
02:28the east will cover most of the country and I think it will be a claggy kind of day, lots
02:32of cloud, lots of humidity as well after another uncomfortable night for sleeping and further
02:37thunderstorms developing. I wouldn't take these too literally, there's a chance just
02:41about anywhere across the southern half of the UK for these thunderstorms to develop
02:45during the day. It is much cooler however, with temperatures only in the mid to high
02:50twenties. Further north, a quiet day once more and western Scotland, Northern Ireland
02:55seeing some decent sunny spells, misty in the east once again. Now later Friday, this
03:02low pressure will tend to disappear away, that's the one that's bringing us the current
03:06thunderstorms and there's another low waiting to the south west, but in between high pressure
03:11starts to build into the north and so actually continued fine weather for Scotland, Northern
03:15Ireland and much of Northern England and a quieter day to come further south as well.
03:19But a lot of cloud cover, again misty in the east, some patchy rain and drizzle about,
03:24a few showers possible, but for many it's a break between any thunderstorms, best of
03:30any sunshine south and west. It will continue to feel warm, temperatures still a little
03:35above average except for that North Sea coast where it will be on the cool side. By Sunday,
03:42well that low pressure to the south west then swings back in again, carried by the jet stream
03:46and that extends the thunderstorm risk more widely into mainly southern parts of the country
03:50at first, sunny spells and risk of thunderstorms before slowly transferring that risk further
03:56north by Monday, but still northern and western Scotland, parts of Northern Ireland largely
04:01avoiding them. However this is how things look for the start of next week. The jet stream
04:06diving to the south, we've got low pressure centred over the UK, it's a slow moving area
04:11of low pressure and it looks like it will persist throughout next week. Some uncertainties
04:16by this stage, by Tuesday, Wednesday about exactly what the weather will be like, there's
04:20likely to be outbreaks of rain spiralling around this low pressure, but the thunderstorm
04:24risk will diminish during the middle of next week. The really clear signal is that temperatures
04:31will go down. Now these two graphs show the temperature trends for Glasgow on top and
04:36London on bottom and you can see both of them well above average over the next few days
04:41and then these red boxes here indicating daytime temperatures during the weekend, they head
04:45back down to the red line here and here that shows around average. They're still a little
04:51above the red line through next week, so still a little above average, but not as much as
04:57we're seeing at the moment and the good news for many places I think is that the blue boxes,
05:02the overnight temperatures will also be dropping off a little so it's going to be perhaps a
05:07bit more comfortable. Here's another exciting chart, it shows the most likely high pressure
05:13or low pressure signal for the next two weeks or so. The more red the box, the more likely
05:18on that particular day that we'll see high pressure and the more blue the box, the more
05:22likely we'll see low pressure and this is the latest model run on top there and it
05:27just shows that really clear signal around the middle of next week for low pressure centred
05:31over the UK and that signal continues into the following weekend. Previous model runs
05:36didn't have such a strong signal so there's still some uncertainty about that, particularly
05:41later next week because certain computer models suggest that it may ease off a little bit
05:46as far as the low pressure is concerned, so there's a chance, just a chance there later
05:50next week that it will perhaps be drier, but otherwise generally low pressure through
05:54next week. We start the week with thunderstorms and through the rest of the week I think we'll
05:58see some outbreaks of rain at times interspersed by sunny spells. Of course you can find all
06:05the very latest on the weather during the next few days on the Met Office social media
06:09channels and you can follow any outbreaks of rain or thunderstorms on the Met Office
06:13app. Bye bye.