10 Day Trend – Turning drier for a time, could it be hotting up? 19/06/19
The end of this week brings some fine weather after what has been a very wet start to June. The sunshine may not last too long, but then could we get some heat next week? It’s just a possibility at this stage Alex Deakin explains.
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00:00Hello and welcome to the Met
00:02Office 10 day trend, 10 days
00:04that could be a bit of a roller
00:05coaster, meteorologically
00:07speaking.
00:08Meteorological summer has got off
00:10to a wet start, a very
00:12wet start. There's no getting away
00:13from the fact that June has been
00:16very soggy so far.
00:17But if you're after some dry and
00:18sunny weather, well, the next few
00:20days promises some of that.
00:22Yes, the weather's settling down,
00:23certainly Friday and Saturday look
00:25fine for most.
00:26It may not last all that long
00:28through the course of the weekend,
00:30particularly early next week.
00:31We are looking at the return of
00:32showers and then things could get
00:34very interesting through the middle
00:36of next week.
00:38There is the possibility,
00:40and I must stress the possibility
00:42of some heat heading up towards
00:44the UK, but it's just one scenario.
00:46There's a couple of possibilities
00:47for next week, as we will talk
00:49about in just a moment.
00:50So if you're planning to head to a
00:52certain festival next week,
00:54well, you may want to stay tuned
00:56for more updates on Glastonbury.
00:59Right. Let's deal with the shorter
01:00term because, yes, lots of showers
01:02around on Wednesday and Thursday
01:04from an area of low pressure.
01:05But what we've been waiting for
01:07for most of June to settle things
01:09down is high pressure.
01:10And finally, it's going to arrive
01:12through Friday and Saturday.
01:13There'll still be some showers
01:15across Scotland, particularly
01:16northern Scotland, on Saturday.
01:18But for most places, this high
01:20calming things down, bringing much
01:22drier weather through Friday and
01:24Saturday and probably for many
01:25on Sunday as well, though notice
01:27this area of low pressure is
01:29lurking.
01:30More on that in a moment, certainly
01:31for most Friday and Saturday
01:33and Sunday looking dry.
01:35There'll be some sunshine and it'll
01:37start to feel a bit warmer as well.
01:39But the mornings will still be on
01:41the chilly side.
01:42What happens after that?
01:43Well, that's where the uncertainty
01:45starts. That area of low pressure I
01:46talked about tries to edge
01:48in and bump away our area
01:50of high pressure. But it's a slow
01:52old process. This low is not moving
01:54anywhere fast.
01:55And that is one of the big
01:57complications about the forecast
01:59for next week.
01:59It's not like we've got low
02:01pressure after low pressure whizzing
02:02across the UK.
02:04It's all very static.
02:05And this weather front is fringing
02:06in, potentially bringing some rain
02:08into parts of the West on Sunday,
02:10more particularly on Sunday nights.
02:12But for many, the high pressure will
02:14hang on for Sunday too.
02:16Now, why is this low just sitting
02:17still? Why is it not moving
02:19very far? Well, for that, we need to
02:20look high up in the atmosphere
02:23at the jet stream.
02:24We've talked about this before, but
02:26the jet stream really is in a
02:28classic omega block situation
02:30as we go into the early part of next
02:32week. This is the omega block, the
02:33jet stream driving south
02:35away from the eastern side of the
02:37United States, then up to the north
02:39across Greenland and then down to the
02:41south again. It's called an omega
02:42block because it's shaped like the
02:44Greek letter omega.
02:45And it's called a block because
02:47when the jet stream's in this kind of
02:49pattern, things just don't
02:51shift very far, very quickly.
02:53The jet stream isn't driving
02:55the low pressure systems on, it's
02:57kind of just sitting still and it's
02:58in this curve, this trough
03:00where low pressures just tend to
03:02mill around.
03:03That's the situation we've seen
03:05so far through June with the low
03:06sitting over the UK.
03:07That's why June has been so wet so
03:09far.
03:10The difference here is that the low
03:12has now shifted a little bit down to
03:13the southwest and that
03:16could have implications for the
03:17weather next week.
03:19But certainly early next week, with
03:20low pressure sitting nearby, the
03:21weather front edging in, there will
03:23be some rain around on this.
03:25But also with the low pressure
03:27down to the southwest, the winds
03:29swirling around an area of low
03:30pressure like this, there is the
03:32likelihood
03:34of some warmer weather,
03:36potentially some very hot weather
03:38wafting up across Spain,
03:40into France, up towards Germany.
03:42And notice we are not too far away
03:44from tapping into that hot
03:46air and it really is very hot
03:48air. So imagine the scenario where
03:49that low pressure is just a little
03:51bit further west and
03:53we could tap into that hot air
03:54across the UK.
03:55But equally, if the low pressure is
03:57just a little bit, we're only
03:58talking about 100 miles or so
04:00further east, then we will stay
04:02in the cool air.
04:03And that's the big conundrum,
04:04especially around the middle part
04:06of next week.
04:08And the computer models are
04:09completely in agreement about
04:11exactly what's going to happen yet.
04:12And there's nothing too unusual
04:13about that. But this is one scenario
04:15from the European computer model
04:18from Wednesday for the forecast
04:20for the middle of next week, for
04:21next Wednesday.
04:22And you can see this scenario has
04:24the low pressure here and all the
04:25hot air right across the UK.
04:27That would see temperatures really
04:29jumping up.
04:30But the same computer model
04:32yesterday was forecasting
04:34something rather different.
04:35This is the same time frame.
04:36So for the middle of next week, all
04:38the hot air was still across
04:40mainland Europe and we were in the
04:41cooler conditions with the low
04:42pressure down to the southwest.
04:44So it's a subtle balance.
04:46One of those two scenarios
04:48likely for next week.
04:49And this graphic sums it up quite
04:51nicely because instead of just
04:52running one computer model,
04:53we run several.
04:54We call it an ensemble.
04:56And this gives an average or a
04:57spread of likely scenarios.
05:00Now, this graphic is
05:02showing that the hot air is very
05:03likely. The white colours, that's
05:05where we're very certain that it's
05:06going to be hot across Italy and
05:08much of mainland Europe.
05:09And the cooler conditions, again,
05:11a lot of certainty with the paler
05:12colours here out in the Atlantic.
05:14But the UK is in the middle
05:16with these green colours.
05:17And that's where the uncertainty
05:19lies. We're kind of in the sweet
05:20spot of uncertainty.
05:22One of those two scenarios.
05:23But which one will win out?
05:25Scenario one, the low pressures
05:27down to the southwest.
05:28We get some heat, some real
05:30heat, something we haven't seen so
05:32far this summer, but it will also
05:33be very humid.
05:34The nights will be uncomfortable
05:36and there's the threats with the
05:38hot and humid air of some big
05:40intense thunderstorms.
05:42The other scenario is that that
05:43low pressure system is much closer
05:45to the UK.
05:46And it's as you were, as we have
05:48been for most of June, it stays
05:50cool, it stays mostly cloudy
05:52and it stays showery.
05:53Now, I hear you say, well, we just
05:55don't know.
05:56And at the moment, we just don't
05:57know between those two scenarios.
05:59But we're pretty confident it will
06:00be one of those two.
06:02So we're saying it's not going to
06:03be high pressure, fine weather,
06:05average temperatures.
06:06It's not likely to be cool
06:09and sunny.
06:10It's not likely to be chopping and
06:11changing very quickly with
06:12weather fronts moving across the
06:14UK. It's going to be either cool,
06:16cloudy and showery or the potential
06:18for that heat and humidity.
06:19If you're packing for Glastonbury,
06:21I agree that that's not
06:22necessarily that useful.
06:24But I think we can say is that you
06:25will need wellies because the
06:27ground is going to be soggy.
06:28You will also need sunscreen
06:30because if the sun comes out for
06:31any length of time at this time of
06:33year, UV levels are likely
06:35to be high.
06:36Stay tuned for details
06:38on any given location as
06:40we go through next week.
06:42And well, the message is always
06:44is stay tuned to the very latest
06:46from the Met Office.
06:47We have the expertise here to
06:48deliver the most accurate longer
06:50range forecast.
06:50Best way to stay up to date is to
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