0:00:03 > 0:00:06Hello there. Fairly quiet through the day on Thursday,
0:00:06 > 0:00:08but as we get on into the end of the week, into the weekend
0:00:08 > 0:00:11and beyond, things are set to turn much more unsettled.
0:00:11 > 0:00:12We do have some rain
0:00:12 > 0:00:14through the day on Thursday,
0:00:14 > 0:00:16across Northern Ireland through the morning,
0:00:16 > 0:00:18getting up into the western side of Scotland,
0:00:18 > 0:00:20we need to watch the rainfall totals because
0:00:20 > 0:00:22there will be some heavy downpours.
0:00:22 > 0:00:23The western side of England
0:00:23 > 0:00:24and Wales pretty grey,
0:00:24 > 0:00:26some outbreaks of light rain and drizzle.
0:00:26 > 0:00:27But the rain in the western side
0:00:27 > 0:00:29of Scotland could be heavy for a time,
0:00:29 > 0:00:30the eastern side drier,
0:00:30 > 0:00:32but a little rain certainly likely.
0:00:32 > 0:00:34Rain crosses Northern Ireland
0:00:34 > 0:00:36then it's fairly cloudy into the afternoon,
0:00:36 > 0:00:38maybe further spells of rain,
0:00:38 > 0:00:39and the rain is lurking there
0:00:39 > 0:00:40in the Irish Sea for the afternoon,
0:00:40 > 0:00:42but ahead of that a lot of cloud,
0:00:42 > 0:00:43some of that quite low,
0:00:43 > 0:00:44but there should still be spells
0:00:44 > 0:00:46of sunshine across East Anglia
0:00:46 > 0:00:48and the south-east into the afternoon.
0:00:48 > 0:00:49You'll get nine, ten degrees,
0:00:49 > 0:00:5111 or 12 in the south and west,
0:00:51 > 0:00:53but a lot of cloud, some of that quite low,
0:00:53 > 0:00:56a little light rain and drizzle to go with that.
0:00:56 > 0:00:57Some damp weather drifting
0:00:57 > 0:00:58across England and Wales
0:00:58 > 0:01:00through the overnight period,
0:01:00 > 0:01:02as the winds pick up from the south and west,
0:01:02 > 0:01:04which will keep things mild for most of us
0:01:04 > 0:01:06to start the day on Friday, but -
0:01:06 > 0:01:07there is an active weather front
0:01:07 > 0:01:09drifting towards the north and west.
0:01:09 > 0:01:11Let's take a look at the big picture for Friday,
0:01:11 > 0:01:13because developments are taking place.
0:01:13 > 0:01:14Weather fronts heading our way,
0:01:14 > 0:01:16lots of isobars on the chart,
0:01:16 > 0:01:18so it is going to be a blustery day on Friday,
0:01:18 > 0:01:20but the winds across England and Wales
0:01:20 > 0:01:22coming in from the south and west,
0:01:22 > 0:01:24so it's mild but cloudy, outbreaks of
0:01:24 > 0:01:25rain and drizzle through the morning.
0:01:25 > 0:01:27This is the squally cold fronts
0:01:27 > 0:01:29which will bring heavy rain and gusty winds
0:01:29 > 0:01:30to Scotland and Northern Ireland.
0:01:30 > 0:01:31That then drifts its way
0:01:31 > 0:01:33across England and Wales,
0:01:33 > 0:01:34probably getting towards
0:01:34 > 0:01:36the south-east through the evening,
0:01:36 > 0:01:37but mild in spite of all the wind
0:01:37 > 0:01:39and rain, 11, 12, 13 degrees,
0:01:39 > 0:01:40but behind that rain
0:01:40 > 0:01:42it turns cold quite quickly.
0:01:42 > 0:01:44Friday night into Saturday there will be snow showers
0:01:44 > 0:01:46across the hills of northern Britain,
0:01:46 > 0:01:47maybe getting down to
0:01:47 > 0:01:49lower levels of northern Scotland,
0:01:49 > 0:01:50before the next system arrives
0:01:50 > 0:01:51for the start of the weekend.
0:01:51 > 0:01:54Yes, a spell of wind and rain.
0:01:54 > 0:01:55Some rain will be heavy,
0:01:55 > 0:01:57the winds could be gusting to gale-force around
0:01:57 > 0:01:59the coast and hills in the south and the west,
0:01:59 > 0:02:00and it's going to feel
0:02:00 > 0:02:02pretty chilly underneath all of that.
0:02:02 > 0:02:03Particularly in the wind,
0:02:03 > 0:02:05which continues to blow through
0:02:05 > 0:02:06the second part of the weekend,
0:02:06 > 0:02:09a brief respite before the next weather system
0:02:09 > 0:02:11comes in to the north in particular on Sunday.
0:02:11 > 0:02:12Another spell of wind and rain,
0:02:12 > 0:02:14need to watch those rainfall totals
0:02:14 > 0:02:15again in the west of Scotland,
0:02:15 > 0:02:17cos they will be totting up.
0:02:17 > 0:02:18Single figures in the north of the UK,
0:02:18 > 0:02:20that bit drier further south,
0:02:20 > 0:02:22and temperatures should be into double figures.
0:02:22 > 0:02:24Does it get any better into the start of the new week?
0:02:24 > 0:02:26Not for the northern half of the UK.
0:02:26 > 0:02:28The next system is on its way.
0:02:28 > 0:02:29Again, a lot of isobars in the chart
0:02:29 > 0:02:31so it will be windy, it's going to be wet again
0:02:31 > 0:02:34in the western side of Scotland, northern England.
0:02:34 > 0:02:36South of that, it's cloudy and breezy
0:02:36 > 0:02:37but relatively mild,
0:02:37 > 0:02:39but again, with that rain
0:02:39 > 0:02:40it's going to feel quite chilly.
0:02:40 > 0:02:42So some very lively weather
0:02:42 > 0:02:43over the next few days,
0:02:43 > 0:02:44and it's going to last well
0:02:44 > 0:02:46on into next week, because we've got
0:02:46 > 0:02:47this very powerful jet stream
0:02:47 > 0:02:49developing across the north Atlantic.
0:02:49 > 0:02:51Core winds will be
0:02:51 > 0:02:52170mph to 200mph or more,
0:02:52 > 0:02:54and that's going to drive a series
0:02:54 > 0:02:57of weather systems across the Atlantic.
0:02:57 > 0:02:59Why is the jet stream so powerful?
0:02:59 > 0:03:00It's because we've got
0:03:00 > 0:03:02a very sharp temperature gradient
0:03:02 > 0:03:04out in the mid-Atlantic,
0:03:04 > 0:03:06you can see the change in the temperature
0:03:06 > 0:03:07of that air at altitude
0:03:07 > 0:03:08across quite a short distance,
0:03:08 > 0:03:11hence a lot of energy being exchanged and a strong jet stream.
0:03:11 > 0:03:12The pressure pattern into
0:03:12 > 0:03:14early December sees high pressure
0:03:14 > 0:03:15in the south,
0:03:15 > 0:03:16low pressure in the north,
0:03:16 > 0:03:18westerly winds bringing some rain
0:03:18 > 0:03:20to the north and west of the UK.
0:03:20 > 0:03:21Signs are that the jet might
0:03:21 > 0:03:23move north into early December
0:03:23 > 0:03:24allowing the high to move
0:03:24 > 0:03:26into the south, settling things down,
0:03:26 > 0:03:28but still in the north and west
0:03:28 > 0:03:30it looks pretty wet and pretty windy.
0:03:32 > 0:03:34We do BBC School Report every year.