00:00Hi there. Welcome to the Met Office 10-day trend. We're into October. We normally expect
00:05areas of low pressure, wet and windy weather at this time of year, although we've certainly
00:10seen plenty of that during the last few months and throughout much of the summer. However,
00:15there is more low pressure to come. This is Sunday, a very large Atlantic system that
00:22will only slowly progress across the country during the weekend and into the start of next
00:28week. Meanwhile, something else is brewing in the Mid-Atlantic, a hurricane that could
00:34influence the UK's weather later next week. Much more on that in a moment. But, a far
00:40cry from low pressure, we've got higher pressure at the moment sitting over the UK, a welcome
00:45respite from all the wet weather we had across central and southern UK throughout September.
00:52That higher pressure building from the north and leading to a widespread fine day on Thursday
00:58Sunday spells one or two showers possible in the far south-east. Otherwise, it's widespread
01:04dry and bright weather. I'm feeling pleasant enough with lighter winds and temperatures
01:09in the mid-teens, although still a cool breeze coming from the North Sea in the south-east
01:13corner. Now, out to the west, you'll notice an area of cloud and rain and that's going
01:19to only slowly edge in through Thursday night and western parts of Northern Ireland and
01:25then eventually those outbreaks of mostly light at first rain come into the Western
01:30Isles. Ahead of that, clear spells and a chilly start again on Friday with temperatures dipping
01:36into the mid or even low single figures in some shelter spots. But, Friday afternoon
01:40for many is dry and bright once again. Sunny spells, a bit more cloud around, certainly
01:46across north-western parts of Northern Ireland, western Scotland, the breeze picks up, the
01:50cloud thickens and further outbreaks of mostly light to moderate rain starting to appear.
01:57This is that very slow moving but very large area of low pressure that's starting to turn
02:03up in the west. Higher pressure losing its influence but still close enough to the UK
02:08in the east to lead to another fine day for many on Saturday whilst this low increasingly
02:15brings unsettled weather into the west. So, a west-east contrast increasingly on Saturday.
02:20We start off with some bits and pieces of rain in the far north and north-west of Scotland
02:24on Saturday. Otherwise, plenty of fine weather, the breeze picks up, the cloud builds and
02:28in the west certainly it's going to deteriorate through the day on Saturday. By the afternoon,
02:34some heavy rain arriving into Pembrokeshire, Devon and Cornwall along with an increasing
02:38wind. That wind in some exposed western parts reaching Galeforce by the end of the day.
02:45It's coming from a warm direction, so 16-17 Celsius despite the increasing clouds and
02:50the best of the sunshine there across parts of central Scotland, eastern England staying
02:55fine throughout much of Saturday. But by Sunday, those weather fronts are making more concerted
03:01progress across the country from the west to the east. You'll notice their weakening
03:04as they move eastwards. So, cloudy, yes, and damp in places but mostly on and off rain
03:10in the east, nothing particularly wet whilst Wales and the south-west see the heaviest
03:17rain during Sunday, especially into the afternoon, another bout of wet weather moving through.
03:22So, the general trend through the weekend is spells of rain increasingly arriving from
03:27the west and the south-west, the wettest weather most likely across Wales and the south-west
03:32with the further east you are, the drier it will likely be certainly at first. But that
03:38low pressure still with us as we start off next week. You'll notice how big it is and
03:44how the jet stream just wraps around it, hence why it's slow moving. Basically, the jet stream
03:50is not pushing it along. It's in this dip in the jet stream and it just lingers across
03:55the UK Monday, Tuesday, perhaps into Wednesday as well, basically bringing what we call a
04:01returning polar maritime air mass. That's where the air originates in the poles but
04:06then returns back across the UK from the south-west. So, it's unstable because it's
04:11coming initially from cold air and then going over warmer seas but it's also going to contain
04:17a lot of moisture because it's coming up from the south-west picking up that humidity. So,
04:22in a returning polar maritime air mass we get frequent downpours, perhaps some thunderstorms,
04:27and the heaviest rain is mostly towards the south-west. With some drier and brighter interludes
04:34in between the showers, it's not going to be raining everywhere all the time. It's going
04:37to be blustery though with a gusty wind, especially again towards the west and the south-west.
04:44Now waiting in the wings, as I mentioned at the start, this. This is Kirk by this stage
04:51moving into the North Atlantic and becoming an ex-hurricane. Now, I can say with confidence
04:57that Hurricane Kirk won't hit the UK next week. How can I be so confident about that?
05:04Well, let's take a look first of all at the official track from the National Hurricane
05:07Centre and that transforms Hurricane Kirk into a major hurricane, that's Category 3,
05:124 or 5 during Thursday and it's going to be a small but powerful beast moving north through
05:20the Atlantic, thankfully staying well clear of land areas. But it does move north and
05:27as it moves north, what happens? It encounters much cooler seas. You'll notice this stark
05:33contrast between the North Atlantic sea temperatures at the moment and the mid or even central
05:39parts of the Atlantic and as a result, the hurricane as it moves north will encounter
05:45cooler seas and when sea temperatures drop below 26.5 degrees, hurricanes lose their
05:51source of fuel. Hurricanes are tropical cyclones that are fuelled by warm seas and when they
05:56lose that fuel source, they typically die away very quickly unless they join up with
06:03the jet stream and that can be another source for fuel but can also transform them into
06:07a different type of low and that's what happens on Monday. Kirk moves far enough north that
06:13it gets picked up by the jet stream so it stops weakening and instead it begins spinning
06:20up in a different way. Instead of deriving its fuel from warm seas, it gets its fuel
06:25from upper winds that spin it and carry it across the Atlantic. In that way, it transforms
06:32from a hurricane into what we call an extra-tropical cyclone or a mid-latitude low or an ex-hurricane.
06:40It's a different feature. Now these systems, just like the one that we're experiencing
06:45at the start of the week, another one coming along there, these mid-latitude lows tend
06:50to be larger spatially but less powerful. However, they can cause some issues and there
06:58are some model predictions, plenty of model simulations that have that ex-hurricane heading
07:04towards the UK. This is from the European model and it sends ex-hurricane Kirk towards
07:09south-western parts of the UK. We don't just look at one model simulation, we look at lots
07:15and here's another simulation from the European model and another and quite a few simulations
07:21have that ex-hurricane or the remnants of Kirk heading towards the UK but not all of
07:28them do. Here are the tracks from 52 simulations and what you'll notice is that they all keep
07:36Kirk running in the same direction through the rest of the week, into the weekend and
07:41Monday. This is its likely position by Monday and it's at this point that it enters the
07:47jet stream that the tracks start to diverge. Now, most of them do still bring something
07:53close to the UK for the end of next week but some of them have the track going a completely
07:59different direction. So, most likely Kirk in some shape or form will come close to the
08:05UK either as an ex-hurricane or merging with another Atlantic low to bring mixed weather,
08:12wet and windy weather but a typical depression that we normally see in October. So, it's
08:18not going to be a hurricane but we could experience the remnants of Kirk or an ex-hurricane by
08:25the end of next week. The uncertainty lies in how it interacts with the jet stream. As
08:30you can see it's the point at which Kirk enters the jet stream that these simulations diverge
08:35a bit more and that's because it's a small but very powerful system and exactly when
08:40it enters the jet stream will have big consequences on where it ends up after that. But most likely
08:47as I say it will come towards the UK and more or less continue the unsettled theme. So,
08:53we start next week with one area of low pressure. This is the most likely weather pattern for
08:57early next week. Low pressure moving into the UK, spells of rain especially in the west
09:02and southwest and slightly below average temperatures. And then the most likely weather pattern for
09:07later in the week is another low. Now, whether that's ex-hurricane Kirk or another Atlantic
09:12low, well, it's interesting to consider but in effect it's basically just more wet and
09:20windy weather and more spells of unpleasant weather basically. Whether it's an ex-hurricane,
09:27the remnants of an ex-hurricane or a different low, I suspect won't make too much difference
09:32on people's lives. It's very likely throughout next week to be highly cyclonic, highly unsettled.
09:40This is the general theme from the European model. So, this averages the pressure pattern
09:45through the week and it shows definite signs for low pressure continuing through next week.
09:51And as a result, this is the rainfall anomaly through that week and it shows the wettest
09:57weather will be towards the southwest, drier towards western and northern Scotland compared
10:03with average. So, a south-shifted jet stream, low pressure or at least several lows through
10:08the week, whether one of them contains the remnants of ex-hurricane Kirk or whether Kirk
10:13gets wrapped up into another system and stays away, well, that's to be decided. We'll keep
10:19you updated right here at the Met Office. Subscribe to YouTube so you never miss one
10:23of those updates.
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