22/09/2016

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0:00:03 > 0:00:05Hello. Low pressure systems, weather fronts, isobars,

0:00:05 > 0:00:08some sunshine and some early-morning mist and fog -

0:00:08 > 0:00:12the weather for the next week or so is a classic autumnal mix-up.

0:00:12 > 0:00:15And it is often, no matter which way you measure it,

0:00:15 > 0:00:19as of Thursday, because Thursday marks the autumn equinox.

0:00:19 > 0:00:22All to do with the position of the Earth rotating around the sun,

0:00:22 > 0:00:25and it's in such a position on Thursday

0:00:25 > 0:00:27that day and night are pretty much equal,

0:00:27 > 0:00:28so from now on,

0:00:28 > 0:00:31the nights will be longer than the days.

0:00:31 > 0:00:34We are pretty much in autumn, and you can

0:00:34 > 0:00:37tell by weather fronts out in the Atlantic.

0:00:37 > 0:00:40The first of those fronts fizzling out during Thursday,

0:00:40 > 0:00:43just bringing cloud across central areas

0:00:43 > 0:00:45and a few showers tracking eastwards.

0:00:45 > 0:00:47Either side of that, some September sunshine

0:00:47 > 0:00:50lifting temperatures potentially over 20 degrees

0:00:50 > 0:00:52across East Anglia and the south-east,

0:00:52 > 0:00:54more typical values elsewhere 15 to 17.

0:00:54 > 0:00:57There'll be showers in the far north-west.

0:00:57 > 0:00:59We'll see a few more showers in the evening

0:00:59 > 0:01:00across Northern Ireland, Scotland,

0:01:00 > 0:01:02north-west England,

0:01:02 > 0:01:04but for many, it will be a dry night

0:01:04 > 0:01:05and a cooler night

0:01:05 > 0:01:08across the south and the east.

0:01:08 > 0:01:09Some mist and fog,

0:01:09 > 0:01:11but that will clear quickly and for most,

0:01:11 > 0:01:13Friday is a fine, bright, dry day

0:01:13 > 0:01:14with sunny spells.

0:01:14 > 0:01:16Notice the wind starting to pick up,

0:01:16 > 0:01:19another weather system in the far north-west.

0:01:19 > 0:01:21Temperatures 15 to 19 Celsius.

0:01:21 > 0:01:23That weather system drifts to the north of the UK,

0:01:23 > 0:01:25but its trailing weather front

0:01:25 > 0:01:27is the main player through the weekend.

0:01:27 > 0:01:30Lots of isobars, so winds picking up,

0:01:30 > 0:01:32and this front bringing a lot of heavy rain,

0:01:32 > 0:01:35looks particularly soggy over western Scotland.

0:01:35 > 0:01:39Turning wet across western parts of England and Wales.

0:01:39 > 0:01:41Ahead of that front, southerly winds

0:01:41 > 0:01:43yet again sucking up some warmth,

0:01:43 > 0:01:45so we could, with hazy sunshine,

0:01:45 > 0:01:47reach 23 degrees Celsius.

0:01:47 > 0:01:49Some uncertainty about the timing of that front,

0:01:49 > 0:01:51but it could be draped across East Anglia

0:01:51 > 0:01:53and the south-east on Sunday morning,

0:01:53 > 0:01:55potentially a damp start here.

0:01:55 > 0:01:57It clears and then we see sunny spells,

0:01:57 > 0:01:58a bit of a breeze,

0:01:58 > 0:01:59temperatures close to the average

0:01:59 > 0:02:02because we've got more of a westerly influence.

0:02:02 > 0:02:05There'll be plenty of showers on Monday,

0:02:05 > 0:02:07and behind me, things are

0:02:07 > 0:02:10getting complicated out in the Atlantic,

0:02:10 > 0:02:13and that's the main problem next week. Why so?

0:02:13 > 0:02:16Well, not to do with this storm, Lisa,

0:02:16 > 0:02:18but more to do with this storm, Karl.

0:02:18 > 0:02:20It is a tropical depression.

0:02:20 > 0:02:22It'll intensify and drift northwards.

0:02:22 > 0:02:27As it does so, it's likely to get close to Bermuda through the weekend

0:02:27 > 0:02:30and potentially may become a hurricane.

0:02:30 > 0:02:33When these kind of storms start to drift north,

0:02:33 > 0:02:35they interact with our weather

0:02:35 > 0:02:37because they interact with the jet stream,

0:02:37 > 0:02:39that fast-moving ribbon of air high up.

0:02:39 > 0:02:41Usually, the jet stream drives the system

0:02:41 > 0:02:43at the ground,

0:02:43 > 0:02:45but when you've got something with as much energy as

0:02:45 > 0:02:46a tropical storm,

0:02:46 > 0:02:48or potentially a hurricane,

0:02:48 > 0:02:49that can influence the jet stream,

0:02:49 > 0:02:51so it adds to complications

0:02:51 > 0:02:53and uncertainty, so the jet stream

0:02:53 > 0:02:55tending to come in like this

0:02:55 > 0:02:57through much of next week,

0:02:57 > 0:02:59which means the wettest,

0:02:59 > 0:03:00windiest weather will be across

0:03:00 > 0:03:02more northern parts of the UK,

0:03:02 > 0:03:04but we are also going to be

0:03:04 > 0:03:05on the warm side of that jet,

0:03:05 > 0:03:07and there's the potential

0:03:07 > 0:03:09to draw up someone warm air,

0:03:09 > 0:03:10especially around the

0:03:10 > 0:03:12middle part of the week.

0:03:12 > 0:03:14I'm using words like "potential"

0:03:14 > 0:03:16and "possibly" because of Karl,

0:03:16 > 0:03:19and the interaction grows the uncertainty

0:03:19 > 0:03:22so generally next week, often quite blustery,

0:03:22 > 0:03:23the wettest in the north-west,

0:03:23 > 0:03:25but Karl adds uncertainty,

0:03:25 > 0:03:27hints it might get a bit warmer.

0:03:27 > 0:03:30We'll definitely be keeping you posted.

0:03:32 > 0:03:33Watch this. It is amazing.