10 Day Trend 16/10/24 – Strong winds and high tides
This is the Met Office UK Weather forecast for the next 10 days 16/10/24
As the jet stream strengthens during the next few days, we can expect some vigorous lows to turn up from the Atlantic. Then, a different shape to the jet stream next week is likely to bring a slightly different flavour to the UK's weather.
Bringing you this 10 day weather forecast is Aidan McGivern.
As the jet stream strengthens during the next few days, we can expect some vigorous lows to turn up from the Atlantic. Then, a different shape to the jet stream next week is likely to bring a slightly different flavour to the UK's weather.
Bringing you this 10 day weather forecast is Aidan McGivern.
Category
🗞
NewsTranscript
00:00Hello, and welcome to the Met Office 10-day trend, a 10-day period in which the jet stream
00:05becomes stronger and then flatter. Here's a quick snapshot to show what I mean by that.
00:11Now, this is the jet stream and the surface pressure at the time of recording. A couple
00:15of things to point out, higher pressure to the east, lower pressure to the west of the
00:19UK, and this very loopy or amplified jet stream running across Northern Europe and the Atlantic.
00:25If I fast forward to the start of next week, however, you'll notice a number of key differences.
00:31One is that the jet stream now runs west to east. It's a much flatter, less loopy shape,
00:38whilst another difference is that higher pressure is to the south rather than the east, lower
00:43pressure is to the north rather than the west. And that change in the bigger picture will
00:49have important consequences on the UK's weather through next week. But I'll go into those
00:55in a moment. And suffice to say, for the time being, we've got this loopy jet stream,
01:01this highly amplified airflow that is leading to a number of interesting things across the
01:07UK. One is that we've got very mild southerly winds. Another is that weather patterns are
01:14slow moving. So many parts of the UK on Wednesday are wet and those areas of rain are slow to
01:21move eastwards, drier in the east at first, but then by Thursday, those outbreaks of rain
01:26are clearing through finally. And actually, it's a fine start to the day for much of the
01:31UK. Sunny spells, just a few showers into Northern Ireland, Western England and Wales.
01:35Otherwise, it's a little fresher out there, not quite as mild, 18 or 19 Celsius, but I
01:40suspect for many, a more pleasant day because of the increase in sunshine and decrease in
01:46rain. Then on Thursday evening, many of the showers fade away and clearing skies with
01:52a cooler airflow across the country will lead to temperatures dipping in the single figures.
01:56So a fresher night compared with recent nights. But a few mist and fog patches will be around
02:02first thing Friday. However, many places will start the day sunny and with light winds before
02:09this area of low pressure moves in through the course of the day. Now, the colours here
02:15are indicating wind gusts above 50 miles an hour. The key is on the right here. And what you can
02:19see is that as that low pressure moves in during Friday day, western parts of Scotland and some
02:25other areas through the Irish Sea, for example, parts of Northern Ireland could experience in
02:30excess of 50 mile an hour wind gusts. Peak winds are likely across the far northwest of Scotland,
02:3560 miles an hour or so on Friday. Now, these winds are coinciding with spring tides. Spring
02:44doesn't refer to seasons when we talk about spring tides, but the oscillation between
02:50spring tides and neap tides that happen associated with the moon phase. And later this week,
02:56we're in high tides, spring tides. And as a result, these strong winds could cause more
03:02coastal impacts than you'd expect with, say, neap tides or somewhere in between. So yellow
03:08warning in force, strongest winds northwest Scotland on Friday. And that's where the wettest
03:12weather will be as well. Some heavy and persistent rain for western Scotland, Northern Ireland. A
03:16few dribs and drabs of rain across the rest of Scotland, England and Wales. Thickening cloud
03:21through the day, although East Anglia and the southeast are likely to get away with another
03:25sunny day before the cloud thickens later. 17 or 18 Celsius in the southeast, 15, 16 further west.
03:33Not feeling as pleasant, though, as the wind and rain arrive. Now, the main area of rain does move
03:39west to east, but again, it's slow moving because of the amplified jet stream. Rather than sending
03:45it west to east quickly, that amplified jet stream means that the rain could develop pulses of
03:51heavier and slow moving areas of rain and could lead to large rainfall totals, 50 mils or so over
03:56western hills, for example, on Friday and into Saturday. And it is going to be slow to clear
04:01across the Midlands, East Anglia and the southeast at first on Saturday. And elsewhere across the
04:07country, we do have brighter skies following a few showers into western Scotland, Northern Ireland,
04:11Wales and the southwest. It's going to feel fresher here at 16 or 17 Celsius. Pleasant enough with
04:18the winds easing through the day compared with the end of Friday. But the afternoon, we've still got
04:23some of that rain lingering in the southeast. Like I say, it is slow to clear. Then late Saturday,
04:31this low spins up virtually from nowhere and it's a deep low. To understand where this comes from,
04:37we need to rewind the clock. We don't need to rewind it too far, just a day or so. And we discover
04:43that this low starts life near the Azores as a relatively shallow and flat feature. Nothing of
04:50great concern at this stage. But during Saturday, what happens is that the jet stream picks it up.
04:55Initially, the low is on the warm side of the jet stream and the jet stream just helps to steer it
05:00towards the UK. Then watch what happens later Saturday. The low just ends up on the cold side
05:07of the jet stream and that's the area where these lows can spin up very rapidly. Look at all the
05:12isobars being added to the centre of that low. It ends up as a very deep area of low pressure.
05:17Now, thankfully for the UK, it looks likely that the deepest part or the most rapid deepening phase
05:24of the low occurs out in the open ocean and away from the UK. Also, the very strongest winds that
05:32we're likely to see associated with this low remain out in the open ocean. But winds are going
05:38to increase late Saturday and into the start of Sunday across the UK, especially western and
05:44northwestern parts. And you can see here again on the wind gust graphic that widely by the start of
05:50Sunday, we can expect wind gusts in excess of 50 mph, in some places 60 mph. And for some of the
05:58most exposed spots of the northwest, 70, 80 mph are possible. But there's some uncertainty on the
06:05precise nature of the wind gusts because it's still a few days away. Different computer model
06:10projections have slightly different tracks and depths of this area of low pressure. Remember,
06:16it deepens really quickly and it goes very deep very fast. So getting a handle on it a few days
06:22ahead is still quite tricky and still that leads to uncertainty about the exact strength of the
06:28winds. But what looks most likely, what is a common theme throughout the model output is that
06:33it's northwestern parts of the UK where we like to see the strongest winds and the biggest impacts
06:37from this low. And again, we've got those high tides to think about. So coastal impacts are
06:43likely. That's why there is this yellow warning for wind across the north and northwest of the UK.
06:49But it's likely to be refined over the next few days. And so, yeah, keep up to date with
06:56Met Office output and the Met Office web pages and app and so on for the updates on this as we
07:02get more detail on the track and depth of the low in question. Either way, Saturday starts off with
07:08sunny spells and showers. The most frequent showers will be in the west. And actually, it's
07:13not a bad afternoon with generally light winds and temperatures of 16 or 17 Celsius away from
07:18any of those showers. But watch how quickly the area of low pressure sends its rain in after dusk
07:25on Saturday quickly becomes wet and windy across western parts of the UK. The rain then sweeps east
07:31during Sunday itself. Now, that rain does move through quicker than Friday's rain, but it is
07:37likely to be slow moving in some parts of western areas or at least heavy at times. So perhaps 50
07:43mils on Sunday afternoon, but or at least through Saturday and into Sunday. Now, the strongest winds
07:52will be affecting western Scotland and there'll be some heavy rain there throughout Saturday night
07:57and into Sunday as well as those strong winds. Temperatures of 16 or 17 Celsius, not feeling very
08:02pleasant, though, with those strong winds. Sunday sees that low move away and into Monday it is
08:10heading into Scandinavia and the very fast-flowing jet stream segment is also moving away into the
08:17continent, with a less strong and flatter jet stream following for the UK. This is the most
08:23likely weather pattern for Tuesday and it shows westerly airflow, higher pressure to the south,
08:31lower pressure to the north and temperatures in the low to mid-teens with the most unsettled weather
08:39for northern and western Scotland and Northern Ireland outbreaks of rain or showers. Fast forward to
08:44Wednesday and this is the most likely weather pattern. Very similar, but a bit more of a
08:49southwesterly airflow than a westerly airflow. Again, the most unsettled weather towards the
08:53northwest, drier and less windy towards the southeast and temperatures not far from average
09:00for the time of year. And that westerly or southwesterly pattern continues to dominate
09:08throughout much of next week. This shows the most likely weather pattern for the next 14 days.
09:13The light blues are southwesterly weather patterns, which, as you can see, make an appearance frequently
09:21through next week, but increasingly we're also likely to see these dark blues, which are the
09:25westerly weather patterns. So, it's likely to stay unsettled through next week. In other words,
09:30low pressure in charge, that's what these blues mean, and westerlies or southwesterlies. Then,
09:37towards the end of the week and beyond, these reds and oranges make an appearance and they are
09:42weather patterns associated more with higher pressure. But, as you can see, much more uncertainty,
09:47a much greater number of these weather patterns come into play. So, what I would say is that
09:53overall, because of that change in weather patterns, temperatures approach the average
09:57for the time of year. The average line here for a centre part of the UK is shown in red,
10:02average overnight temperature shown in blue, that's the line, and then these boxes show the
10:06most likely temperature each day and each night. And, as you can see, through next week after a
10:11mild spell, those temperatures are likely to trend back towards average because we see those
10:16westerlies return rather than southerlies. So, overall, westerlies or southwesterlies throughout
10:23the upcoming week, changeable, but always wettest and windiest towards the northwest,
10:29drier and less windy towards the southeast, and then just those subtle hints of higher pressure
10:34later. But really, that's beyond the 10-day period, beyond the 26th of October we're talking
10:40about. And, of course, we'll keep you updated right here at the Met Office on all of that. Bye-bye.