Despite forecasts for a colder weather in February shaped by Greenland blocking highs, very mild conditions have prevailed so far, especially in southern Britain, putting the month on track to be one of the warmest on record. Temperatures now look set to drop closer to normal next week, though.
Long-range forecast models generally went for a strong high-pressure anomaly to the north and north-west of Britain, with an above-average incidence of Greenland blocking highs during February. This type of pattern traditionally brings cold winter weather to the UK with a relatively high frequency of northerly and/or easterly winds. The dominant pattern in the first half of February has sometimes seen a Greenland blocking high. Still, it has not been particularly strong, and with pressure also tending to be high over southern Europe, the jet stream has tended to pass in between the highs and bring mild and wet weather to much of Britain.
Particularly in the southern half of Britain, the first half of February has been exceptionally mild. The long-running Central England Temperature series, which goes back to 1659, saw a mean of 8.1C for 1-15 February, which, if this were sustained in the second half of February, would give us the warmest February on record. The 15th was particularly exceptional. Although no new maximum temperature records were set (the highest being 18.1C), the overnight minimum temperatures were more remarkable, with many areas falling no lower than 12C. The warmth was delivered by south-to-south-westerly winds pulling air masses in from a long way south.
It currently looks unlikely that this level of warmth will be sustained, for temperatures look set to fall much closer to the long-term normal during the last week of February. Still, many areas of the UK, particularly the south, look on course for having a February within the top ten warmest on record. But it seems unlikely that Greenland blocking highs will play a significant role in the second half of February. Much of the upcoming week will be mild with south-westerly winds and high pressure to the south and southeast, and then the subsequent colder weather will feature showery west to north-westerlies and low pressure, with potential for some gales.
Today's weather has started dry and cloudy for most, although there are some well-scattered gaps in the cloud sheet, so a minority of us have been seeing some sunshine. This weather pattern will continue in eastern Britain for the rest of today, but rain will spread eastwards through Northern Ireland during the rest of the morning. During the afternoon and evening, it will stay wet in Northern Ireland until near dusk, while rain will spread from west to east through Scotland, Wales and England, reaching eastern counties by evening. The rain is forecast to be persistent and substantial even in sheltered eastern counties. The Met Office has an amber warning for rain and potential for flooding covering much of the southern half of England and south and west Wales starting at 3pm today and finishing at 9am tomorrow.
Temperatures in northern Scotland will reach around 8C, but elsewhere, temperatures will again be somewhat above average for the time of year, with highs of between 12 and 14C in most parts of England and east Wales. It will remain very mild overnight, especially in England, under the persistent rain, with some places falling no lower than 11 or 12C. Even in Scotland, where some less mild air will spread from the west, it will fall no lower than 5 to 7C for most.
The rain will have cleared away from most areas by dawn on Sunday, though some may persist in the far southeast of England until around mid-morning. Sunday will tend to start cloudy but will generally be much brighter than today, especially in eastern Britain. There will be a scattering of light showers, mainly in the west, but many places will miss them and stay completely dry. It will be another very mild day, with temperatures probably reaching 15C in parts of southeast England and 10 to 13C elsewhere.
Some rain will spread from west to east early Monday, followed by mainly dry and bright weather. Tuesday looks cloudy for most, with some rain in Northern Ireland and Scotland, but generally dry weather in England and Wales, particularly towards the southeast. The rain will push south-eastwards through England and Wales on Tuesday night and looks set to push back northwards on Wednesday, giving much of England and Wales a wet day. It will remain mild, with temperatures reaching or exceeding 10C in most places. However, some colder air will move into Scotland late on Tuesday and early on Wednesday, giving maximum temperatures of 5 to 7C on Wednesday and some wintry showers on higher ground.
Especially from Thursday onwards, we expect a pattern change to colder, showery west to north-westerlies, and it will become very windy for a time, with gales likely in some areas. Temperatures will only fall to around average for the time of year, but it may feel rather cold after recent mild weather. It will be cold enough for some snow on high ground, especially in the north, but it looks likely that showers will fall predominantly as rain at low levels.
