10 Day trend - Only slow changes in the final third of November 20/11/19 - video Dailymotion

Met Office

The first 20 days of November have seen a repeating weather pattern, only slow changes are expected as we go into the weekend. Next week will again be dominated by low pressure but will it turn colder as we head into December?

Transcript

00:00Welcome to your 10-day trend from the Met Office,

00:0310 days that takes us to the end of November.

00:06November, so far, has seen a repeating weather cycle,

00:10which means it's been very wet for some

00:12and pretty dry for others.

00:15We're only going to see a slow change to that

00:17over the next five days.

00:19Gradually, very gradually, it should

00:21be turning a little bit milder as we go into the second half

00:23of the weekend.

00:25After what's been quite a dry week,

00:27it will also be turning wetter, particularly

00:29across parts of the south and the west.

00:32Let's take a look at the bigger picture.

00:34High pressure is kind of influencing our weather,

00:37even though it's a few thousand miles away across Siberia.

00:41These lows are edging in, and I do mean edging in.

00:45And as they're combining, they're

00:47squeezing the isobars together, which

00:48is why we've got a cold southeasterly wind blowing

00:51for the next couple of days.

00:53But these weather fronts are only

00:54making painfully slow progress, hardly edging in at all

00:57by Thursday.

00:58What we need is a bit of a kick, a bit of oomph,

01:01and this low pressure will provide that.

01:04It's being driven by the jet stream,

01:05and it looks like taking a spell of very windy weather

01:08into parts of Spain, Portugal, and France,

01:11along with some heavy rain.

01:12There is a bit of uncertainty about the exact track

01:14of that low, and it does have the potential

01:17to bring some heavy rain across parts of the south,

01:19especially so on Saturday.

01:21As it edges in, though, things get mixed up,

01:24and notice the isobars aren't as close together.

01:26So those cold winds will slowly be easing

01:30as we go into the weekend.

01:31But there is the potential for that rain, especially

01:34across the south, that could be quite heavy.

01:36Compared to the start of the week, it won't be as frosty,

01:39but with lighter winds, there will still

01:41be some pockets of frost at this time of year

01:43where we have clear skies.

01:45Now, let's take a look at the bigger picture,

01:47but high up in the atmosphere, and take

01:49a view of the jet stream, quite a lively looking jet stream

01:53driving down to the southwest of the UK.

01:55That's what's taking that low pressure into France and Spain.

01:58And this is the kind of pattern that we've

02:00seen quite frequently through November,

02:02allowing low pressure systems to affect especially

02:05southern parts of the UK.

02:07That's how we go into the weekend,

02:09but we will perhaps see a subtle change by the time

02:13we get to the second half of the weekend.

02:14By Sunday, the jet stream isn't amplified.

02:17It's not going way to the north and driving to the south.

02:20It's more coming straight across the Atlantic.

02:22Now, this we call a zonal weather pattern,

02:26and this is perhaps a more typical weather pattern,

02:28especially so in autumn.

02:30And that tends to, instead of looking at low pressures down

02:33to the south, it tends to pick up low pressures out

02:36in the Atlantic and move them across the UK.

02:38So they're not as slow moving, and they're

02:40bringing spells of wet weather back across the UK.

02:43Tightly packed isobars, so yes, at times it will be windy,

02:47but with the low bringing in milder air from the Atlantic.

02:51So instead of those slow moving weather systems,

02:54the weather gets a bit of a supercharge

02:57from the jet stream, and we'll see the weather patterns

02:59changing a bit more rapidly, at least for a time,

03:01into the early part of next week.

03:03But it's still low pressure, so there'll still

03:05be bands of wet and windy weather swinging through,

03:08but it perhaps won't be as cold.

03:10Now, I talked about those weather patterns shifting,

03:12but it's not a dramatic shift.

03:14Notice particularly close to the UK,

03:16the jet stream isn't especially lively,

03:19and signs are through next week that you could almost

03:21see that jet stream trying to bend back and become

03:24more amplified again.

03:25So that's the big question mark next week.

03:28Will the jet stream remain more zonal,

03:30or will we see a return to that more amplified pattern

03:34and things becoming slow moving again?

03:36So yes, a change into the early part of next week,

03:38but then uncertainty beyond that.

03:41Let's have a look at some charts for later next week.

03:44This is the American model showing

03:45a chart for Wednesday night of low pressure

03:48sitting pretty much slap bang across the UK,

03:50rather like Monday's chart.

03:52That would again bring mild weather in from the Atlantic

03:54and a spell of wet and windy weather as well.

03:57But for the same time, the European model

04:00has low pressure close to the UK, but it's further east.

04:03The jet stream isn't as noticeable.

04:05We're on the cold side of the jet,

04:07and there's some very cold air not far from the UK.

04:12And you can see that if this model's right,

04:14that cold air could start to slip southwards

04:16right at the end of next week, bringing significant chill.

04:21Now, the uncertainty is shown in this graph here.

04:24This is a meteorogram showing temperature trends.

04:27This one's for Exeter.

04:28There's the data along the bottom.

04:30The red blobs are the likely maximum temperature.

04:33The larger the blob, the greater the uncertainty.

04:35So at the start of the period, we're

04:37pretty certain that the red blobs

04:39will be sitting underneath the average temperature line.

04:42So yes, it's going to be cold for the next few days.

04:45But there's a trend there.

04:46It does get warmer, gets milder through the weekend.

04:50And then into next week, well, there's

04:51not a great trend there.

04:53The blobs are sitting pretty much on that average line.

04:56But notice they're getting larger.

04:57There's quite a big spread, especially by the time

05:00we get to the end of next week.

05:02And that's the uncertainty.

05:04Will it be turning colder, or will it be milder?

05:07We are pretty confident that the main themes are low pressure

05:10will dominate next week.

05:11So expect further spells of wet and windy weather.

05:14But the big uncertainty, the big thing

05:15we'll be keeping an eye on as we go towards December

05:18is, will it be a mild wet and windy,

05:21or will it be turning a little bit colder?

05:23So that's what we'll be keeping an eye on as we

05:25go into next week.

05:26For you to keep an eye on the day-to-day weather,

05:28well, the best thing to do is to subscribe to our YouTube

05:31channels or follow us on Twitter and Facebook.

10 Day trend - Only slow changes in the final third of November 20/11/19

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