This is the Met Office UK Weather forecast for the next 10 days, dated 01/05/2024
A feeble jet stream makes for slow moving weather patterns and a mixed forecast. The bank holiday weekend looks particularly tricky before higher pressure may move in next week.
Bringing you this 10 day trend is Met Office Meteorologist Alex Deakin.
A feeble jet stream makes for slow moving weather patterns and a mixed forecast. The bank holiday weekend looks particularly tricky before higher pressure may move in next week.
Bringing you this 10 day trend is Met Office Meteorologist Alex Deakin.
Category
🗞
NewsTranscript
00:00Welcome along to the Met Office 10-day trend and welcome along to May, a month
00:05where the longer range forecasts always are that little bit more tricky to pin
00:11down. And one of the reasons for that is the jet stream this month tends to have
00:15a bit of a break. It becomes generally less active and a bit harder to nail
00:21down. This is the bigger picture and showing the jet stream, that fast-moving
00:25ribbon of air, high up in the atmosphere. It's almost circulating around on
00:29itself at the moment and there's a low-pressure system in here out to the
00:33west of the UK. Now that kind of breaks down that weather pattern over the next
00:37couple of days and then we have almost two feeds, but two weak feeds of the jet
00:42stream as we head through the next four or five days. And remember it's the jet
00:47stream that drives our weather system. So when the jet stream is weak and
00:52meandering, our weather patterns become fairly slow-moving and often
00:57reasonably inactive. So let's rewind the clock and see what that means for our
01:03low-level weather patterns. The pressure pattern, as I said, the circulation
01:07allowing this low pressure to just kind of mill around to the west of the UK. But
01:11it's actually this low pressure being pushed up from the south by an arm of
01:15the jet stream that's more influencing our weather over the next couple of days
01:19before one of those weaker bands of the jet pushes another little low up across
01:25the UK into the weekend. That's the one that's giving us quite a few headaches
01:30for this weekend and of course it is a back holiday. We will get to more of that
01:36in just a moment, but again let's rewind the clock and look at the shorter term
01:41because this low coming up from France is bringing with it some pretty warm air,
01:45some heavy downpours through Wednesday night, a couple of Met Office warnings in
01:50place for thunderstorms, some intense rain, lots of flashes of lightning, a lot
01:54of spray and surface water on the roads across the south for Thursday morning.
01:58Don't normally focus in on Thursday but wanted to show you the temperature
02:02contrast in places on Thursday because we are seeing the warmer air come up. So
02:06where we see some sunshine 21, 22 degrees, maybe even 23 on the west coast of
02:11Scotland, whereas in the east with the easterly wind it's going to be
02:14significantly chillier, particularly where it stays grey and on the cool side with
02:19the cloud and the rain across the southwest. So quite a lot going on with
02:22our weather on Thursday. By the time we get to Friday, well we're going to see
02:27that low coming up from the southeast bringing further pulses of heavy even
02:32thundery rain through the night and during the course of the day. Should be a
02:36bit brighter in the southwest and again probably a fine day on the west coast of
02:40Scotland. So this low pressure bringing some heavy downpours during Friday and
02:45then eyes down to the southwest. That low I talked about earlier being pushed
02:50along by that reasonably weak jet stream as we head towards Saturday and
02:55Sunday, probably even into Monday as well. Now it looks reasonably potent on these
03:01graphics or quite a few isobars around it certainly initially but because that
03:06jet stream is fairly weak some of the computer models really struggling to
03:11identify exactly where this low pressure is going to be. It must emphasize there
03:15is a lot of uncertainty at this stage about the weekend, more so than usual.
03:21And let's have a look at some of the computer output. This is the Met Office
03:24model, the one I've just shown you but now in kind of black and whites with
03:28that low pressure. This is midday on Saturday down to the southwest with
03:32quite a few isobars coming around it so reasonably potent feature. The European
03:37model has low pressure in a similar position although it is further
03:41southwest and it doesn't have as many isobars so it's not as intense and that's
03:45the big question mark because if it's slower to come up like this one then
03:48many places will still be fine on Saturday. But if it's quicker to come up
03:52then certainly across the south we will see increasing breeze and some outbreaks
03:57of rain during Saturday. Let's compare those two main models the Met Office
04:01model and the European model for Sunday and well by this stage that low
04:06pressure is really losing its identity. You can still just about make it out in
04:10there. It's still there in the ECMWF the European model as well but it is
04:15further south and by the time we get to Monday well the pressure patterns are
04:19what we describe as flabby where there's not many isobars around. It is a bit of a
04:25mishmash generally low pressure still dominating so likely to stay fairly
04:30showery. But there are some discrepancies in the way the computer models are
04:34handle it when we compare the two and of course if you're a regular viewer of the
04:3910-day trend you'll know that we don't just compare one run of computer models
04:44we run the models many many times in what's called an ensemble forecast and
04:48this is a plot of what you can get from the European model when we run them many
04:54many times. Now this is showing the same time frame Saturday and you can see the
04:58isobars for the main run here but each of these black dots is when you run the
05:04model many times a position of that low and you can see there's not a lot of
05:08agreement. The UK is under here that main run keeping the low down to the
05:12southwest but other runs of the European model have that low in a similar
05:16position to the Met Office model so further in across southern England and
05:20some of them even as far east as East Anglia. So this is quite a broad range of
05:24where that low pressure could be we're talking only three or four days ahead so
05:29that is more uncertain than usual there's less what we call confidence in
05:35the forecast than usual and it's a similar picture if you look at Sunday
05:39again where is that low going to be by then the low is pretty diffuse anyway
05:43but it could be clearing away from eastern parts of England but it could
05:47also be down further south and west across the UK. So as I said more
05:51uncertainty than usual in the forecast and that is shown by this graph here the
05:57confidence index often meteorologists and forecasters talk about how
06:01confident they are in a weather forecast and sometimes the forecast is
06:06reasonably straightforward and we have high confidence but this weekend's we
06:10have unusually low confidence. So this graph is showing the time going forward
06:16there along the bottom and the index going up to 1. 100% confident at the top
06:21there and in the shorter term well that's where we're at or close to. This
06:26dotted line is the average and as you would expect with forecasts going
06:31forward you'd expect that the confidence in them to drop off naturally but this
06:36line is showing what the actual forecast is for the most recent run from the
06:39European model green is slightly above average but red is below average and
06:43look at that drop just drops off just as we get to the bank holiday weekend the
06:49confidence really plummets unusual to see this level of low confidence if
06:56you like in the forecast in this reasonably short time frame head so it
07:00is giving us a few headaches as I say there's like to be low pressure nearby
07:05but exactly where and when we see the rain at this weekend it's just too early
07:09to say so one of the key messages want to get across is actually it's likely to
07:13be mixed that's one thing we do know about the bank holiday weekend but
07:16please do stay up to date over the next couple of days one of those where your
07:21app is going to tell you something and then six hours later it will tell you
07:24something else so do keep up to date with the forecast best way to do that is
07:29to stay tuned to Met Office output and keep up to date with our YouTube
07:33forecasts we can say there's like to be some rain with low pressure nearby but
07:37it's not going to rain everywhere far from it and it's now May so when the Sun
07:41is out and because our air is coming up from the southwest it is likely to feel
07:46quite warm when the Sun is shining question is where will the Sun be
07:51shining as I said for details on that really need to stay up to date this is
07:55the this is the Met Office model then for Sunday with that low pressure edging
07:59in and those weather fronts around but that does kind of fizzle out keeping
08:04pressure generally low as we head into bank holiday Monday which is likely to
08:08be a showery day but notice there is a ridge of high pressure just trying to
08:13topple in and that is a sign perhaps of things to come beyond the bank holiday
08:18yes higher pressure is likely to move in during the second half of next week
08:24that's what this is showing blue is low pressure dominating red is high pressure
08:30dominating now the dates going forward are along the top previous computer
08:33model runs down the side here what we can see is reasonably strong signal over
08:38recent model runs of a bit of a switch yes low pressure is going to dominate
08:41for the next few days and through the bank holiday weekend but reasonable
08:46signal there is things getting redder from Wednesday through to Thursday that
08:50higher pressure in some form and that's crucial in some form is likely to move
08:55in through at least the second half of next week and probably dominate through
08:59the following weekend as well this is again from the European model the most
09:05likely scenario for next Wednesday with high pressure in here but say it's most
09:12likely it still is only a 25% probability so that means there's a 75%
09:18chance or a 3 in 4 that it will look somewhat different to this so that's
09:24what we're talking about when our confidence is dropping off a little bit
09:26but we are reasonably happy that some former of the high pressure will sit but
09:31the position of the high will dictate where the winds are coming from and as
09:35we've seen over recent weeks that really will determine the feel of the
09:39weather because if the high pressure is sitting out to the west that will
09:44generate more northerly winds if it's sitting a little further east it could
09:47generate some southerly winds and that will as I say dictate the feel of the
09:51weather so what we can say about the second half of next week is yes
09:55confidence remains reasonably low but higher pressure is more likely than low
09:59pressure and higher pressure is where the air is sinking so that brings out a
10:03greater chance of drier weather but the wind direction the position of the high
10:07will be crucial to how the weather feels so also for conditions individual days
10:14next week do stay tuned to the forecast because although the confidence does get
10:18back closer to average and actually it gets into the green again for the
10:22following weekend it is still reasonably low through next week just not as below
10:28the average as it will be through the weekend okay plenty to talk about then
10:33and as I said please do keep up to date particularly if you've got plans through
10:37this bank holiday weekend and the best way to do that of course is to hit
10:41subscribe on our YouTube channel