BBC monthly outlook
Summary
Turning rather chilly and unsettled.
Saturday 19 January—Sunday 27 January
Cold week with a chance of snow for some.
This week looks to be rather unsettled with low pressure diving south across the UK into Western Europe. It will generally be cloudy with rain coming in along fronts that are expected to arrive Sunday and again on Tuesday. Scattered sharp showers will drift in at times mainly for western counties, and these may be wintry of thundery in places.
Beyond Tuesday, high pressure will build in the Atlantic with a broad area of low pressure developing in the Western Mediterranean. The weather will be chilly but a bit dull for the UK until Thursday, when a ridge of high pressure will extend to the north of the UK and help to develop some easterly winds. There is still some uncertainty on the exact timing and intensity of these winds, with a chance of high pressure staying further west and keeping the winds northerly. In either case, however, it will be colder than average with a brisk wind at times.
If easterlies develop for the latter part of the week, expect scattered snow showers drifting in from the east across the North Sea, mainly impacting eastern and central Britain with western counties staying dry but cold with largely clear skies. Frosts are expected overnight for most places throughout the week with crisp afternoon highs. There is still a risk (~20%) that easterlies will struggle to develop later in the week. It will still be cold in this scenario, but snow showers in the east would be unlikely.
Monday 28 January—Sunday 3 February
Staying cold with further snow risks.
The end of January and the start of February see a continuation of the cold weather for the UK, with a period of even colder weather becoming increasingly likely. Model solutions are beginning to converge on a generally cold but dry week, with some pulses of colder air bringing in a risk for wintry weather.
High pressure in the Atlantic is expected to persist through the week, with generally lower pressure over mainland Europe and the Western Mediterranean, occasionally shifting north and closer to the UK. A rather complex weather pattern unfolding, is leading to a higher degree of uncertainty on the day-to-day specifics of the forecast, with minor shifts in the location of the low and high pressure areas leading to large swings in temperature and precipitation forecasts for the UK. There is a chance (~20%) of high pressure in the Atlantic breaking down and retreating further south, leading to a more progressive flow bringing fronts and milder but windier weather into the UK.
Monday 4 February—Sunday 17 February
Colder than average but with some mild weather too
There continues to be the likelihood of some cold and perhaps wintry weather through mid-February. Stratospheric weather patterns above the Arctic at a height of around 30 km have been much weaker and warmer than usual in January. However, these patterns are expected to strengthen again through February.
What this means for us down at the surface in the UK, is that at some point in mid or perhaps late February we should see the colder air retreat into Scandinavia and Russia and a return to milder weather with progressive fronts moving in from the west. There can be quite a delay in the low levels of the atmosphere responding to this stratospheric pattern, so the cold pattern is expected to linger for most of Northern Europe, including the UK, through to at least mid-February. However, we may start to see some milder breaks in the cold weather by mid-month, with occasional lows moving in from the north-west bringing some milder air for a day or two. Similar to previous weeks discussed above, the complex weather pattern is leading to some uncertainty in any day-to-day specifics.
Next Update
We will take a closer look at the risk for snow showers in the east later this month and just how long we will be in the grips of this cold spell.
https://www.bbc.co.uk/weather/outlook