Some woke to a ‘surprise’ covering of snow across Scotland this morning. Expect more of this as we head into the weekend as lows slide underneath a building dome of cold air.

Yellow warning out for snow across northeast Scotland tomorrow!

These deflected lows are a result of the Arctic Oscillation flipping back negative, triggered by strong cross polar stratospheric warming.

This strat warming supports a -AO but unfortunately not a -NAO hence the still active Atlantic pattern. This cold spell is fairly temporary as the swell of arctic air south has forced the jet south.

Cold will be marginal over southern Britain hence lows pushing through the English Channel will likely bring rain to far southern England but further north into the colder air and snow is likely to break out over parts of Wales and Midland England.

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Further north easterly winds strengthen and it will turn bitter, particularly along the North Sea coast. I expect to see snow in eastern areas as models show moisture entrained in this cold easterly. Snow showers could bring a covering from Aberdeenshire to the Borders as well as through the Central Lowlands reaching the Glasgow area.

One of two lows push through Friday-Saturday and it’s the second (Saturday) which bears watching for the threat of plowable snow. Stormy conditions are expected to the south of the lows with storm-force winds for the Atlantic coasts of France, Spain and Portugal.

Here’s the latest GFS surface/precip charts.

Across the north, where skies are clear, it will turn cold with fast frost and ice formation following sunset. Where there’s snow cover, winds are light, I expect lows to push -10C.

High pressure slides over the UK from Iceland early next week. We could push for this winter’s coldest minimum. (-12C)

See video for the discussion.

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