02/09/2017 Weather for the Week Ahead

Hello there. As we step into the first weekend in September

and the first weekend in meteorological autumn,

it's going to be a weekend of two halves.

We've got a fine start to the weekend with high pressure

sitting out towards the south and east,

but things are set to change later in the weekend with

the arrival of this frontal system from the Atlantic.

So for many of us, Saturday will shape up to be a fine day -

lots of dry, sunny weather with light winds around too.

Just one or two isolated showers scattered here and there

across parts of eastern England,

perhaps southern Wales, but I think most places avoiding the showers.

And up to around 21 degrees in the south-east

will feel quite pleasant, the high teens further north.

But then things start to change Saturday night as this area of rain

and strengthening winds moves in from the west.

So some heavy rain at times across Northern Ireland, Wales,

south-west of England too.

It'll be reasonably mild, though, to start your Sunday,

with all the cloud and wind around.

Now, through the day on Sunday, the front moves in from the west.

We've still got that area of high pressure sitting

out across the near continent there.

I think that will keep eastern parts of England

and perhaps eastern Scotland dry for quite a good part of the day

but elsewhere the cloud and the patchy rain

and strengthening winds moves in from the west.

So rain right through the central spine of the country, I think,

by the afternoon, and temperatures between around about 15-19 degrees.

So, that frontal system, then,

tends to weaken as we move through Sunday night and on into Monday too,

but we've still got the remnants of a front, I think.

So, Monday's sort of quite a nondescript kind of day.

We've got a lot of cloud, some patchy drizzle here and there.

It's towards the far north-west,

though, that we see some more persistent rain working in again.

Now, this is a cold front, it's brining some wet

and windy weather, but across the rest of the UK, actually,

we've got quite mild conditions with the cloud.

There'll be some brighter spells around too - 22 degrees or so,

so certainly mild, but then we'll start to see the cold front

working in once again from the north-west.

So, heading on into Tuesday now

and it's likely that we'll see that front bringing some wet

and windy conditions across parts of Northern Ireland and Scotland,

slowly edging its way south-eastwards,

the far south-east likely to stay dry

and reasonably warm for a good part of the day

but there's some uncertainty through the middle part of the week

about how quickly that cold front gets out of the way.

Now, what we've got at the moment in the north Atlantic is

two branches of the jet stream, one a bit further north

and one a little bit further south.

Now, how these two jet streams interact is really going to

affect how quickly that weather front clears away.

The first scenario is that they could well combine

and strengthen too, so with that fairly strong jet stream,

that could clear away this cold front

through the middle of the week and then that would open the doors

for an area of higher pressure to build.

So that would bring a slightly quieter and drier

and brighter spell of weather through the middle of the week.

But they may interact differently,

in that the northern section of the jet stream clears away

to the north and we're left with this slightly weaker

southerly branch of the jet stream

which will be slower in clearing away the initial cold front,

and then we are likely to see another area of low pressure

pushing in from the north-west.

So a couple of scenarios through the middle of the week,

but what we can agree on is by the end of the week,

we're likely to see more unsettled weather across the north-west

of the UK, some brighter

and some drier weather likely towards the south-east.

So, it is a rather unsettled outlook.

There will be spells of rain in the forecast

over the next ten days, some brighter interludes.

Windiest towards the north-west and you're more likely to stay

a little bit drier and warmer too in the south-east.

We'll keep you up to date throughout the weekend. Bye-bye.