11/09/2016 Weather for the Week Ahead

Hello. We may well now have entered the meteorological autumn

but the weather has other ideas.

It's certainly not following that way,

because last week we had temperatures into the high 20s

in the Channel Islands and the south-east,

and this coming week, we're likely to see temperatures certainly

into the high 20s for several days. We may reach 30 degrees once again.

The reason - a southerly wind. The transition is already underway.

We're watching this major Atlantic low coming into the north and west.

As it does so, it's pulling in this southerly wind,

so it looks in contrast, after a wet day for parts of England

and Wales on Saturday, much brighter and drier.

A chilly start, mind you,

in contrast to what's coming ahead in the next few days.

Even a bit of mistiness around as well.

Then some fair-weather cloud, a rogue shower,

but for most of us, dry, bright, and in southern and eastern areas,

it'll feel warmer, but windier up towards the north and west.

Gales coming in with this area of rain.

So potential risk here, because there could be severe gales

into the north-west approaches accompanying some fairly

persistent rain through Sunday night and into Monday.

So obviously here it won't be so warm and bright,

and overnight, not so cold either and not as chilly a night either,

as we start Monday morning, compared with Sunday morning.

But that major Atlantic low pressure still with us in the north and west,

so the contrast here between that and the southerly winds drawing in

some sunshine, particularly to eastern areas on Monday.

And it's in eastern areas, central and eastern areas, where we

are likely to see those temperatures starting to get into the mid-20s.

It'll be warm rain further north and west as well,

but you can see quite clearly this weather front here

is our dividing line between the Atlantic fresh air

and this continental rather warm and increasingly humid air as well.

So there's quite a lot of uncertainty as to how quickly

this weather system is then going to push eastwards,

and it really does drag its heels.

It almost gets stuck across the western side of the UK

for two or three days.

So it really allows that southerly wind to establish itself,

and as it does, obviously temperatures rise

by both day and night, and the humidity starts to rise as well.

So increasingly uncomfortable by night, I should imagine,

for sleeping as that humidity starts to rise.

And further west, always the potential growing for some

really intense, thundery activity, and as you can see,

the temperatures getting up into the mid-20s across northern England.

and into southern Scotland approaching the low 20s as well,

as that warm air continues to travel further northwards.

As it does so, we do see a subtle change in our wind direction,

dragging more of a south-easterly into eastern shores,

so perhaps a little more cloud here,

but all the time, that weather front really stagnating.

More likely south-west England, Wales, Northern Ireland

for the big, torrential downpours through Tuesday and Wednesday,

but again, take this one slightly with a pinch of salt

and keep tuned to the forecast for the details day-to-day,

because again, even on Thursday, that same caveat -

it's still hanging around towards western areas in particular,

allowing that warmth to continue to establish itself further eastwards.

Even by Thursday potentially the mid to high 20s.

It's more likely later in the week, Thursday, Friday, even into

the weekend before that finally gets a kick and heads its way eastwards,

and then all of us will see that change, that thundery breakdown.

We lose the heat, we lose the humidity, and behind it we get in

the fresher Atlantic air, this westerly,

but also this little bump in the isobars,

that's a ridge of high pressure, the Azores High,

and that is usual for this time of year.

You normally see it hanging around the southern half of the UK,

starting to drift away, allowing the low pressures to come in,

but at the moment it looks as if the Azores High will hang on

at least in southern areas.