05/12/2017 Weather for the Week Ahead

Hello and welcome along to our latest thoughts on how the weather's

going to pan out in some detail over the next four or five days

but then we'll just push the horizon into the body of next week.

The script for this week is that we start the week fairly quietly.

That was the way of it on Monday, we'll repeat that on Tuesday.

By Wednesday and Thursday, things get very wet and very windy,

as you will see, and then the end

of the week turns much, much colder.

So let's do that stage by stage.

As I say, Tuesday, bit of a replica of Monday,

a lot of settled weather around, say,

for the northern and north-western parts

of Scotland, wet and windy fare here.

A little bit of brightness around,

8 to 10 degrees,

not too bad at all.

But this is where we begin to see

the first signs of a change,

especially across northern and western parts

of the British Isles

because this low pressure

is going to gradually drag its wind

and rain into those northern and western areas.

How much wind? Well, it could be a gale,

small comfort perhaps, but it gives us

the mildest day of the week with

the temperatures widely in double figures,

that's the last time I will be saying that

in this particular forecast.

As the low pressure churns its way

up towards the coast of Scandinavia,

we begin to see the last of the mild,

south-westerly winds slipping away

towards the near continent

and notice the temperatures.

In Norwich, for example,

11 degrees in the morning

as we tuck into some of that cold north

and north-westerly wind,

we conclude the day in Norwich

at around about 8 degrees

and falling, as you will see.

Notice the number of isobars here.

This is a very deep area of low pressure.

That could be severe gale force,

if not storm force, winds

coming down the eastern shores

and coming from a very cold direction

because as we kick into

a north and north-westerly,

we just tap into that reservoir of cold air,

just sitting there waiting

to the north of the British Isles.

So Friday, across all parts of the British Isles,

will be a cold day.

The showers will be wintry,

not necessarily just on the higher ground,

given that that will be the temperature profile,

add in the strength of the wind in the east,

you could be closer to feeling like -4,

rather than +2.

And as we start the weekend, not a deal of change,

still a lot of isobars on the chart,

especially so through

central and eastern parts.

Still plenty of showers,

especially along those eastern shores,

North York Moors, absolutely seeing

a covering of snow here

and other the high ground

across northern and eastern parts.

Towards the latter part of the weekend,

this high pressure just trying

to tumble in to calm things down

across the western side

of the British Isles,

but my eye is fixed on the area of low pressure, throwing frontal

systems down towards the western side of the British Isles.

Now as that low pressure drags

its way down across

this south-western quarter,

if you are properly in the mild air associated with that low pressure,

then I think you're going to see leaden skies and it will rain.

Here comes the "but" -

if, however, as that low pressure

comes down and across

the south-western quarter

of the British Isles,

you're more likely to be

in the colder air,

then I think you're going to stay in that rather wintry regime

and there will be some ice, there will be some snow.

The uncertainty comes in the boundary between -

where is the warm air, where is the cold air?

I think it'll be colder

in the north and east,

I think it'll be milder

in the south and west,

but where's the slow going to fall

on that boundary level

and just how much? See you soon.