First, I have to say that I cannot tell you for definite, where or when, and how much, it will snow over the next few days. But you will get some. Probably quite a bit. Perhaps quite a lot.
This plunge of cold Arctic air was fairly easy to forecast, and I think I got it pretty spot on, those of you who follow my forecasts may remember me mentioning it a week ago.
However, the next few days are very difficult, perhaps impossible, to give an exact output on where and when snow will fall perhaps until even 6 hours beforehand, as the low pressure system is complex, and has only just started to develop, and the situation is very mobile.
So this is more of a general overview, and my best guess.
Tonight will be cold, eventually down to -5’C. I do not rule out some snow in the early hours, as I think that the snow showers which are hitting the coastal regions may go far enough inland if they get organised. This will probably not be clear until about midnight/1am as to whether it will happen.
Friday will be cold, perhaps a wintry shower in the wind but nothing much, probably no more than -1’C. -4’C overnight.
Saturday is where it gets interesting. As I suggested on Monday, it looks like the low pressure will split into two as it develops, one will push itself westwards (ready for Sunday), the other will push itself eastwards, and as it does, there will be an area of snow for much of the south and some central areas of England. As I advised above, it is very difficult to work out where will be hit. But I am expecting perhaps around 5cm of snow in Reading. Potential is there for 15cm, equally, it might just be 2cm. Temperature of -1’C.
Saturday night probably will be dry and very cold, -7’C though I would not be surprised to see -12’C if there has been a lot of snow and it is a cloudless night.
Sunday is where I get into a state of disbelief. It seems to be too much snow to be true. The second area of low pressure that I mentioned is supposed to then move across the south of the country, bringing blizzard conditions. Anything up to a foot of snow. My brain tells me that this cannot be right as I have not seen this happen before. I have bought a few tins of food just in case. I am confused as it would be something very extreme and I have seen these things projected in models before, although up to a week away, and they never deliver. This time it is in a much more reliable time-frame so maybe we will have a huge blizzard.
And after that? Well I originally said no to a white Christmas, as I was expecting temperatures of 10’C by then.
Monday will see further falls of snow at times, temperatures still around 0’C and it could be very cold overnight, -7’C perhaps.
Tuesday sees the mild Atlantic weather systems really try to organise themselves, as our cold air moves away slightly, it will still be a cold day, maybe -2’C at best, chance of some snow showers but nothing organised looks likely at the moment.
Wednesday also looks similar – wet and mild air to the south wants to move north.
I think that there will be a lot of potential for disruption next week – these areas of low pressure will eventually win out and bring wet and milder weather. But there will be snow to come first.
I am still saying – Christmas day in the south will be mild at 10’C. But I think in the north, it could be blizzard heaven.
Milder air to reach all before the end of the year…but the winter will be back.