The Met Office deep dives into the forecast for the rest of this week which suggests disruptive snow.
Part transcribed:
Cold arctic air in the north, milder in the south. Over the next few days, that boundary between the two tends to oscillate across the UK so that first the cold air sinks south. A band of rain clears the UK overnight into the start of Wednesday. But then an area of low pressure in the Atlantic pushes a weather front back in across the UK.
Initially, a spell of rain comes into the south and southwest on Wednesday night into Thursday morning. But as that band of rain mixes with the cold air across central parts, there’s likely to be some significant and disruptive snow. We keep the cold air there in the far north, then further ahead, that low pressure looking increasingly dominant now.
@westbridgfordwirenews The Met Office has issued an updated yellow weather warning for snow this week. A band of rain, sleet and snow will move north on Thursday. At low levels, accumulating snow will be very variable, some locations will see 2-5 cm accumulate over a few hours before gradually thawing later Thursday and overnight. Over higher ground, mainly above 200 metres, 5-10 cm of snow is likely, with higher totals for higher ground of North Wales and the south Pennines. . #nottinghamshire #derbyshire #fyp #foryoupage #nottingham #westbridgford #notts #nottinghamnews #derby #peakdistrict #uksnow #snow #metoffice #metofficeweatherwarning ♬ original sound – West Bridgford Wire News
This has been a significant change in the computer model outputs over the last 24 hours. Now, if you’d been paying attention to previous weather forecasts, there was a reasonably strong signal that into the weekend, the low pressure that arrives later this week would sink away into the continent and the whole of the UK would return to colder air from the north or the east.
But what now looks most likely is that low pressure exerts more of an influence across the UK, sending milder air across the country so that the cold air becomes displaced to the far north. And actually, you can trace those differences in the computer modelling back to very subtle differences at the start of the forecast out in the mid-Atlantic, where this low pressure is currently sitting.
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And we’ve also got the jet stream picking up that low. Now, what’s happened in the last 24 hours with much of the computer modelling is that they’ve developed this low just a fraction more than before. And that is an important difference because that means that it can exert more of its influence from the Atlantic.
It can send the rain further north across the UK, snow in places, and it can displace the cold air more firmly to the north, rather than the cold air winning and pushing the low to the south. So there’s been this important change in the computer modelling heading into the weekend in terms of that low that’s currently sitting in the Atlantic and how much it takes over the UK’s weather into the weekend and returns much of the UK to milder and in places, wetter weather, with the cold air displaced to the far, uh, north of Scotland.
But after that, well, we’ve got a bit more, I’d say, confidence about weather patterns and how they’ll evolve through next week and beyond, and I’ll be covering that in a bit more later on. But let’s take a look at the next few days. First of all, uh, because there’s plenty to talk about.
And at the moment, as I mentioned, we’ve got this band of rain sinking south and we’ve already got the wintry weather into the north. So for the rest of Tuesday and overnight, we’ve got further snow showers coming into the north and northwest of Scotland. Ice warning in force. I’d say, in parts of north and northwest Scotland, we’ll see another two to five centimetres, perhaps eight centimetres over higher parts of the northwest Highlands.
And we have certainly seen some significant snow building up during Tuesday across Shetland. So Scotland will stay roughly in the same kind of regime over the next few days. We can expect further snow showers coming in. This is the start of Thursday. Again, more significant snow showers building up across the north and northwest of Scotland.
Nothing exceptional, uh, for Scotland for the time of year. Of course, it often snows in February, but, yes, could cause a few issues. But you might have noticed further south, we’ve got some more significant snow arriving by this stage. Let’s rewind to the end of Wednesday. Wednesday’s a fine day, bright for many, just some lingering cloud and dampness across the far south and southwest.
Before that low that I mentioned in the mid Atlantic pushes the spell of rain back in from the south and, um, southwest, and it will be rain across much of the south of Wales, south of England, really, Birmingham to mid Wales southwards. This is rain and it’s heavy and it’s persistent.
Could be a few issues, although the dry weather recently will help mitigate against the worst of the impacts. But nevertheless, it’s a wet start to the day across much of south Wales and southern England as that rain moves in, then playing it forward. And what we’ve got is that rain mixing with the cold air and turning increasingly to snow.
To understand why, just want to show this. This is really interesting in terms of the contrast across the UK and this is the freezing level. So the height of the zero degree isotherm and what it shows is normally, as a rule of thumb as meteorologists, we look at 2300 metres for the height of the zero degree isotherm for snow to be falling at the surface.
So it doesn’t have to be below zero at the surface. But if it’s below zero, about 200 metres, then it means that snow at 200 metres won’t have time to melt. Or if it does melt, then it’s going to be, well, sleety or whatever. But also the, uh, cooling that you get for evaporation as that precipitation falls from the sky also helps to keep it as snow.
