10 Day trend - How’s Christmas looking? 18/12/19
Will be a wild or white Christmas? Met Office meteorologist Aidan McGivern has the 10 Day Trend.
Category
🗞
NewsTranscript
00:00Hello, and welcome to the Met Office 10-day trend. Christmas fast approaching, just seven
00:05days to go now, but it's not looking particularly festive during the run-up to Christmas, certainly
00:11wet and windy over the next few days into the weekend, some especially heavy rain for
00:15southern Britain and strong gusty winds at times. The good news, if you are hoping for
00:21something a bit more settled for Christmas week, is that the signs are high pressure
00:25will start to build in, turning things gradually calmer. But for the time being, we are facing
00:30an onslaught of low pressure systems, weather fronts moving in for the Atlantic, but particularly
00:35coming up across the UK from southern parts of Britain. And that's why during the rest
00:39of this weekend to the start of the weekend, it's southern Britain that will bear the brunt
00:43of the heavy and prolonged rainfall, but there'll also be strong winds in places during the
00:48next few days. All of this active weather brought about by a powerful jet stream, just
00:52rewinding the clock there to Wednesday, and you can see this strong section of the jet
00:58stream moving across the Atlantic and heading towards the UK. The jet stream, of course,
01:03that fast-flowing current of air high in the sky, it tends to deepen and transport areas
01:08of low pressure around the globe. And when it is pointed towards the UK and slightly
01:12south shifted like that, we can expect plenty of low pressure systems keeping the weather
01:17unsettled. And I'm not going to go through the detail of the next few days because you
01:21can find more detailed weather forecasts through the Met Office app, through the Met
01:24Office website, YouTube channel, and so on. And it's on the website where you can find
01:29all the details of the weather warnings over the next few days, warnings in force for wind
01:33and for rain. So if you've got travel plans in the run-up to Christmas, certainly worth
01:38planning your journeys carefully because of potential impacts from those outbreaks of
01:43rain and the strong winds. Heading into the weekend, subtle changes are gradually going
01:50to occur. You can see the jet stream still a powerful part of the jet stream pushing
01:54across southern parts of the country, but we lose the most powerful part by the start
01:59of next week. And that means slowly but surely through the weekend, the weather turns a little
02:05less unsettled. We're still going to see some wet weather on Saturday, courtesy of this
02:11area of low pressure moving across southern parts of Britain. Elsewhere, for many places,
02:15it's a case of sunny spells and showers on Saturday, and then further showers coming
02:20in from the west on Sunday. But you can see by this stage, most of the lows are moving
02:26away and behind them, a brief bump in the isobars there, a brief ridge of high pressure
02:31to bring something a little more settled for the end of the weekend. So rain on Saturday
02:38in the south, slowly turning drier through the weekend and becoming less windy, but still
02:44a few showers, but still fairly changeable temperatures around average. Heading into
02:50next week, then the Christmas period, of course, nothing says Christmas more than a probabilistic
02:55pressure trend over the UK. But this is essentially a useful chart for showing a big change in
03:02the weather patterns for next week. And let me explain what's going on. We don't just
03:06run one computer simulation where we're talking about seven to 10 days time. We run 30 or
03:12more. And this sums up all the outcomes from all those different computer models where
03:17they all agree, where they all say that low pressure is likely to be in charge. We get
03:22strong blue colours where they all say high pressure is likely to be in charge. We get
03:26strong reds. And in between, you get something around this colour. Now, moving forward, these
03:32are the dates for the forecast. So we're looking at Christmas Eve here and Christmas Day here.
03:38And these are the different computer model runs. So this is the most recent one. This
03:42is 12 hours earlier and this is 24 hours earlier and so on back in time. So the important thing
03:47to note there is that over the next week or so, those strong blues, all the computer models
03:52agreeing that low pressure is going to be close to the UK. But you can see a significant
03:57change on Christmas Eve or Christmas Day. We go from the strong blues to the strong
04:01reds. Many of the computer models then agreeing that high pressure is likely to replace the
04:07low pressure around about the Christmas period. So a big change in weather patterns. How does
04:12that look? Well, up to Christmas Eve, this is the likely situation. The jet stream south
04:18shifted carrying areas of low pressure rapidly, one after the other, across southern parts
04:23of Britain. But watch the change around about the Christmas period. The jet stream gets
04:27a shunt further north and it's likely to be pushing to the northwest of Britain. Still
04:32some low pressure systems crossing northern Britain, still some changeable weather here.
04:37But with high pressure building further south, we can expect the weather to settle down more,
04:42drier, calmer. Now, the winds are still going to be generally coming in from a mild direction,
04:47so we're not expecting a cold spell next week. But where any clear skies happen at night,
04:52we can expect some frost and fog patches, especially for southern Britain. More changeable
04:57weather further north. So not a classic white Christmas. That doesn't look particularly
05:02likely in most places, but certainly higher pressure through next week. Drier and calmer
05:09for a time, a break in that wind and rain. But yeah, if you've got travel plans over
05:14the next few days, do take a look at the forecast, the latest weather warnings and plan your
05:20journeys accordingly. You can follow us on social media for all the very latest. But
05:24for now, just time for me to say, have a Merry Christmas and Happy New Year. Bye bye.