BBC monthly outlook
Summary
Unsettled start with drier, colder weeks to follow
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Saturday 30 January – Sunday 7 February
Unsettled start to February; turning colder
This weekend will see a weak ridge of high pressure over Scotland and the North Sea keeping northern and eastern areas drier. A set of weather fronts will cross the southern half of the UK, bringing heavy rain and hill snow to Wales, the Midlands, and South England on both Saturday and Sunday. A colder air from the north will lead to a sharp frost for Saturday night and Sunday morning. Sunday will generally feel noticeably colder than Saturday for many. Next week, as the colder air lingers over the country from Sunday into Monday, there will be a more widespread risk of lowland snow Monday night and into Tuesday morning.
This is due to yet another advancing front from the west bringing bands of snow and cold rain. The front will also bring in some milder Atlantic air, so temperatures will recover to a bit above normal for southern areas. From midweek through the end of the working week, lows will weaken and drift away to the south with bands of rain or wintry precipitation easing for most. It will also slowly turn colder with temperatures dropping to near or a bit below average. High pressure is expected to build over Scandinavia as we head into the weekend. This will lead to the development of a strong easterly wind on Saturday and Sunday. This will bring a sharp cold air from Russia into the UK and may well bring some wintry showers to eastern areas. There is some uncertainty on the magnitude of the cold at the moment, which is highly sensitive to the exact strength of the high (and easterly winds through North Europe).
Monday 8 February – Sunday 14 February
Colder start to the week but less cold later
In mid-February, high pressure is expected to remain over Scandinavia at least for the first half of the week, keeping things rather cold. This setup is similar to the classic "Beast from the East" from 2018. There is potential for some heavy snow showers for eastern areas for the first few days of the week. However, this is very sensitive to the strength of the high to the northeast, and a minor shift will see the easterly winds fail to transport the coldest air from Russia all the way to us in the UK. We have high confidence that the high pressure system will develop, and it will turn colder than normal, but lower confidence on exactly how cold (and the potential for snow showers). Later in the week, the high in Scandinavia is expected to shift a bit further south and southeast, nearer to Belarus or western Russia.
This shift would kill off any easterly winds through the North Sea, shifting them more southeast. This is still a cold flow for us in this setup, but much less cold than the first half of the week is expected to be. This weather pattern is also drier for the UK, so some crisp afternoon sunshine is expected. The main risk for the mid-February forecast is for the easterly winds to linger for longer into the second half of the week if the high pressure system stubbornly remains over Scandinavia. This would make for a very cold, windy week across the country, but more so for eastern areas where it will feel very raw outside.
Monday 15 February – Sunday 28 February
Gradually turning drier but colder
For the second half of February, the drier and colder pattern from mid-February is expected to continue for the third week of the month. High pressure is likely to remain strong to the north of Europe and into Northeast and East Europe. This will result in some colder air sticking around for the UK as low pressure systems travel south into the Mediterranean. There is a chance for some very cold days to develop if high pressure lines up an easterly wind to transport the very cold air from Russia into the UK, but these would only last for 2-3 days at most at any one time. For the final week of February, high pressure to the north of Europe is expected to slowly decline and shift further away.
This will allow the jet stream, a ribbon of fast-moving air in the upper atmosphere that drives weather systems, to return to North Europe. This pattern would allow Atlantic weather systems to bring wetter but milder air in from the sub-tropical Atlantic as cold air becomes increasingly confined to Russia and Scandinavia. There is some uncertainty on the exact timing of the pattern shift though, and these cold winter highs tend to be rather tenacious and slow to decline. The main risk for late February is that high pressure and colder air stick around through the end of the month and into early March, making for a cold but somewhat dry February overall.
Further ahead
With the latest model data we will hopefully be able to pin down the magnitude and length of the cold outbreak in early-to-mid February with greater accuracy.
https://www.bbc.co.uk/weather/outlook
Just a reminder - their Monthly forecast was issued only a day or so back.