A colder outlook for next week

Getting your outfit right at this time of year is tricky. The day might start off nippy but by mid-afternoon you are lugging around a big coat in warm sunshine that feels almost like summer. There can be wind and rain, which then clears by 11am, leaving bright skies, but still the threat of a downpour. So carrying an umbrella means keeping your wits about you. It's far too easy to leave it behind when the sun does decide to come out. Next week does look colder in a north then easterly flow. 

This week, southern Britain will have temperatures in the high teens rising into the low 20s, even up to 25C for SE England by Friday. 

Through the weekend and for next week, the UK will be in a colder air mass which could bring the first frosts by night in the north, morning fog for commuters and a real autumn chill if the wind picks up. 

Feeling cooler by Sunday, maybe just reaching 20/21C in the far southeast on Sunday afternoon 

A strong zonal jetstream has been powering across the Atlantic this week, bringing low pressures our way with wind and rain. Huge meandering loops develop in the jetstream over the next few days, slowing everything down. As high pressure builds over the north Atlantic, it will gradually replace the weekend low pressure. Sunday night looks cooler in a northerly flow behind the low. After some bouts of heavy rain and unsettled conditions, the high pressure will bring fair weather with lighter winds by Monday. However, colder air will be brought south over the UK from the Arctic, replacing the warmer air of this week. 

A colder outlook for next week

Mon 22nd - Mon 29th Sept  Seven-day mean anomalies of 2m Temperature from the ECMWF Sub-seasonal range ensemble.

This high pressure will slowly edge towards Scandinavia, toppling towards the Baltic States. Ahead of the high, colder air will be dragged into NE Europe, but behind the high, milder air will move up the Atlantic to the northwest of Scotland. Much of the UK will be under settled, dry and calmer conditions next week with light winds but a cool breeze from the NE. In any sunshine, it will still feel pleasant enough but it will be chilly after dark.

As the high extends eastwards, there could be showers picked up in the easterly flow over SE England and East Anglia. For many, there looks to be a lot of fair weather, more settled conditions than the rain of this week which was much-needed rain.