The well advertised cold NW air flow which has origins traced back to Arctic Canada is arriving this afternoon and evening across the UK. Expect the air to cool as the wind picks up later this afternoon into evening. Showers will become frequent and increasingly wintry at all levels tonight and through Tuesday likely causing disruption.

Thanks to a collision between subtropical and polar air, the cross Atlantic jet stream has accelerated to 260 mph.

The jet stream running across the UK this week will be very strong, exceeding 260 mph, which is why things are going to turn more unsettled with strong winds and plenty of showers pic.twitter.com/qfANzarU3G

— Met Office (@metoffice) January 14, 2018

The main cold front brought wind and rain last night and this has opened the door to the polar maritime air but the coldest air which is still out over the Atlantic, doesn’t truly arrive until dark this evening.

Note the difference in temperature at 5,000ft between 1500 and 0000 hours tonight!

Plenty of snow showers blowing in on a brisk WNW wind through Tuesday extending into Wednesday.

This has triggered a widespread yellow warning for snow and ice.

Latest GFS snow depth by Wednesday morning.

Once Wednesday arrives our eyes turn to a deepening Atlantic low which is due to cross the UK late Wednesday into Thursday. This has a high chance at becoming our next named storm. As well as severe gales, this thing could be a significant snow maker for areas north of the centre. Exact track will be crucial.

As it stands and according to the latest model runs, the Central Lowlands of Scotland could be hit hard but even a 50 mile shift north and the heavy snow is into the Highlands with just rain between Glasgow and Edinburgh.

Snow depth in the wake of the storm.

Tags: scotland snow, UK Snow