BBC monthly outlook
Saturday 24 February—Sunday 25 February
Increasingly cold but mainly dry and settled.
A vast high pressure area over Scandinavia will continue to intensify and extend its influence further west, so overhead the UK by Sunday. This will allow a fresh E to SE wind flow to develop, feeding in progressively colder air from the east as milder Atlantic air and associated fronts remain at bay well to the west of the UK. Whilst dry for much of the weekend, there will be an increased threat of snow showers drifting in from the east on Sunday night. Frost overnight will be the main hazard, with widespread sharp frosts (-4C to -6C quite widely, locally down to -9C). The cold air will be accentuated by the fresh easterly winds.
Monday 26 February—Sunday 4 March
Bitterly cold end to winter with snowfall.
The start of next week marks an uptick in the arrival of a very cold airmass from Scandinavia and N Russia. The UK is very likely to experience a severe episode of winter weather conditions, possibly with close to record cold for this time of year. Similar very cold easterly spells at this time of year in the past include February 1962 and 1986, and more recently 2005 and 2013.
Fresh E to NE winds will start to drive in lines of snow showers from the North Sea from the word go next week into the eastern half of Scotland and England. A few will filter further west, but will be much lighter here. Snow accumulations starting to occur on Monday, but there is a threat of a zone of more organised snow showers pushing SW across the UK on Monday night and Tuesday, which could give more widespread and significant snow accumulations - especially over eastern Scotland, north-eastern England and down through parts of the Midlands. However, there is uncertainty on amounts with weather models often having a poor handling on such situations several days ahead. There will also be the risk for a stream of snow showers into southern parts of SW England Tuesday night into Wednesday. Due to the cold and very dry air, the snow will be powdery in nature and will easily drift in the fresh NE winds. Severe frost overnight and daytime maxima struggling to rise above 0C, especially the higher parts of England.
Extreme wind chill values (feels like temperature) expected on Tuesday to Thursday (feeling like -10C to -14C). Regarding snowfall, it will still be the eastern half of the UK most exposed to frequent and heavy snow showers and disruptive accumulations midweek. However, there is the threat of a band of widespread and heavy snow, accompanied by fresh easterly winds, moving northwards over the southern half of the UK between Thursday night and Saturday, although confidence is very low on this potential event. Regardless of this, temperatures will remain well below average through the second half of next week.
Monday 5 March—Sunday 18 March
Gradually less cold, although still a snow risk.
Analysis of longer-range models suggests that there will be somewhat of a transition during the second week of March and more especially around mid-month. The strong high pressure over N Europe that was responsible for the severe cold outbreak at the start of March should weaken, opening the door to low pressure influence from the south (which will in the meantime give disturbed weather to S Europe). It is therefore likely to turn more unsettled with a greater frequency of wet and breezy days, and with cold air masses still lingering over the UK this will present the risk of further snow.
Indeed, there is the risk for further disruptive wintry weather entering the early part of the meteorological spring, with snow, ice and overnight frosts all possible as cold air is only gradually eroded by mild SW air flows. However, a repeat of the imminent significant cold weather is unlikely by the time we reach mid-March.
Next Update
How influential could the return of low pressure areas be by mid-March? Will we experience stormy conditions again after mid-month or will there be another late burst of wintry weather?
https://www.bbc.co.uk/weather/outlook