Morning everyone, what a week of weather to come. Intense cold and plenty of #snow. Enjoy or endure, here it comes.
What a week to come for British weather. You may be wishing it was “potentially historic” heat and sunshine if that is more your thing, rather than intense cold and the threat of deep snow. Or just weighing up the inconvenience/opportunity of a snow day. With a pool of very cold Polar continental air (504dam on 1000- 500hPa thickness charts, very unusual for the UK) over us by Wednesday, bitter wind chill, snow showers from the east and then a low pressure from the south striking the very cold air, winter is hitting hard.
This morning snow showers are working their way in from the east, off the North Sea. This will continue over the next few days. It’s a chilly start but the coldest air won’t be across us until midweek and that’s when the east wind will really pickup so that the wind chill will be extreme. There will also be ice and severe frosts.
Although the focus for the start of the week’s snow is for eastern Britain, lines of showers will develop, streaming further inland, with some spots seeing several cms of snow as they just keep on feeding in. A few miles away there could be barely any snow. This variation will be marked, that is the nature of showers and also this particular set up of flow from the sea as the showers funnel and jostle to move over the land. See Sea Effect Snow link at the end of this update. Smaller features appear in the flow too enhancing the upper forcing which results in larger clusters and heavier snowfall.
Later in the week the focus for snow will change as an area of low pressure develops and moves up from Iberia. There is some uncertainty about this part of the forecast as the low will include milder air, but as the fronts hit our very cold air snow is likely for a time. The SW of Britain looks prone and southern Ireland. These fronts then head north, probably bringing even more snow, and then its what will happen in southern England, if there will be rain, freezing rain or a dumping of snow
Don’t just look at an app and think that is going to give you a detailed answer. This is about areas of risk and shorter time detail. Coming in from the North Sea start of the week, but some showers working their way right across the UK and other parts seeing lots, some missing out, watch the radar.
Then later in the week the risk of for southern Britain, still with a flow of showers off the North Sea
Temperatures
Remember, you have the still air temperatures with a maximum and minimum every 24 hours. So, if you see a forecast, say a display on an app that says +2C, that temperature may occur for 40 minutes in the afternoon. If you were sheltered from the wind, standing outside in the shade, that is the air temp. reading. However, the minute you turn a corner into the wind, boy it feels different. By mid-week it will all be about the wind chill. The cloud is increasing from the east, we won’t have the glorious sunshine which was around at the weekend, there won’t be that warmth to cheer us either.
People keep on asking, how cold is it going to get, wanting a number. Record breaking lows take days of air sitting above snow fields. -10C is the UK February lowest daytime max. Our air will be whizzing across the UK on these Siberian easterlies. It may not be about the actual numeric air temperature, but it will feel bone chillingly cold mid-week and for anyone out in that for any length of time, there is a serious risk to their health.
Snow
If you are in a county by the North Sea you are likely to see some snow, high ground several cms, and areas affected by convergence zones or streamers could get 5 -10cm, a few spots or higher ground 15 to 20cm. 10cms is 4 inches. There are signs by late Monday of a line in from the Wash and off the Thames. The Met office have a Yellow Be Aware warning this afternoon for eastern and SE England as the impacts of the snow begin to appear.
This flow of showers continues into Tuesday but with another feature appearing from the North Sea, a small developing low which could bring heavier more widespread snowfall into Yorkshire, particularly North York Moors early Tuesday, across to the Pennines and Peaks and across NE Britain. It will be accompanied by strong winds, bringing the risk of blizzard conditions and drifting for a time. There is an Amber Be Prepared warning from the Met Office on Tuesday. Through Tuesday snow could reach across Britain to Wales.
The showers keep feeding in from the east through Tuesday into Wednesday with heavier lines and other parts missing the worst. There is another Amber warning for NE Britain for the snow and the risk of thundersnow. Snow, thunder and lightning. Transport and power supplies could be effected.
Utter cold
Wednesday will see the coldest air across us and a fresh easterly wind. This brisk wind continues into Thursday and it will feel bitter. It could then strengthen as the low pressure approaches from the SW.
More Snow
There is a yellow Be Aware warning out for Thursday for this approaching low, Snow and wind. This might be upgraded to Amber as the details firm up and there is more confidence in the impacts and locations. The Met Office warnings page is down at the moment but that can happen to the best of websites (forum overload f09f9889) so keep an eye on how the forecast develops this week. This is not a drill, or media hype, this week will bring severe winter weather and disruption.
Sea Effect snow coming across the North Sea
Cold weather, your health and heating costs