Monday 11th January 2021

So we are in a bit of a battle between somewhat milder air to the west, and colder air to the north and east. Milder air (with rain) will win temporarily to start the week, but colder air will quickly return. And then it gets complicated.

Of course, where rain meets cold, it can turn to snow. For us down here it is unlikely – the battleground should, this week at least, be further north – say midlands or north of England.

Again, tricky forecasting this week – mild and cold air will be fairly close to each other, so the difference of say 50 miles could make a great deal of difference to the weather – and 50 miles a few days out in atmospheric terms is really quite tiny. So don’t be surprised if some of this is wrong.

Thanks to Laurie for the photograph of a frosty scene from last week.

Tonight will be cloudy with outbreaks of rain spreading down from the north – more persistent in the early hours. 8’C.

Tuesday starts cloudy with a bit of patchy rain. This will clear south, and slowly the sun will increasingly shine.

Starting quite mild at around 9’C but colder air filtering down from the north during the day and temperatures will drop to around 4’C by mid-afternoon. A frost to start the night, down to around -1’C, but cloud will thicken with some patchy light rain from the early hours, and temperatures tick up a bit.

Wednesday morning start cold and wet, the rain becoming heavier and more persistent. As the morning goes on, the rain edges east, temperatures increase as the mild air probably arrives, up to around 10’C. I say probably for the mild air, as it is a close call – on current modelling it will be around 3’C just 40-50 miles to our north-east. The rain also becomes generally patchier and lighter in the afternoon.

During the evening, the band of more persistent rain edges west – or perhaps technically backfills, so further persistent and fairly heavy rain is likely – but again some uncertain on how far west, though I think we should expect it. Probably still in the milder air overnight, but uncertain.

Thursday is likely to see further rain at times, some heavy, as the weather front erratically moves east. It could easily rain for much of the day – clearance time is very uncertain, and there is a small chance of a little back edge sleet or wet snow before it clears – SMALL chance! Temperatures uncertain, more likely in the mild sector to start, say 9’C but dropping later in the day. Cloudy and cold overnight, the odd spot of light rain possible at first, down to around 2’C. Fog possible.

For Friday we are back in cold and dry. There should be some sunshine, but don’t expect too much. Around 5’C. A frost possible at first in the evening, depending on cloud amounts, but cloud thickening as the night goes on and temperatures picking up a tad.

Confidence significantly reduces for the weekend, but the most likely outcome is:

Saturday sees rain crossing. It should be rain, but some wintriness either before or after rain cannot be ruled out. Uncertain on weather front timing and temperatures at this stage.

Sunday dry with some sunshine. Cool or cold, somewhere between 5’C and 8’C.

The most likely outcome for next week is to see cold air spreading down from the north again. Too early to be certain and too early to know whether there could be snow in the mix, or whether just dry. It could well be very, erm, interesting.

Also worth noting by which point we would be 2 weeks from the sudden stratospheric warming event on 5th January, and we often get significant cold spells starting somewhere between 2-4 weeks after. Whether this is a response from the SSW, or is just a continuation of the previous weather patterns I have no idea.

Until the fallout from the SSW is determined, there is no point really in looking further ahead. Even 5 days away is tricky in post-SSW circumstances, let alone a couple of weeks or a couple of months as I like to do.

I wish you an acceptable week.

Leave a Reply

Your email address will not be published. Required fields are marked *