After an unusually mild start to November, winter is preparing to make a dramatic entrance. Temperatures are set to plunge below freezing next week, with new weather maps showing a massive blanket of snow sweeping across the UK. Fresh data from WX Charts suggests that by 6am on Wednesday, November 19, a 500-mile-long snow front will stretch from John O’ Groats at the northern tip of Scotland right down to London.

Some areas are forecast to receive up to 20 inches and the heaviest accumulations are expected in the coldest regions of northern Scotland, where the latest model even suggests up to 39 inches on higher ground. WX Charts predicts the first flakes will begin falling as soon as 3pm on Thursday, November 18, particularly across northern England and southern Scotland. Overnight into Wednesday, further bands of snow are shown sweeping across Manchester, Newcastle, northern England and Scotland, before pushing southwards through the early hours and into the morning.

The Met Office’s long-range forecast for November 18 to November 27 states that the colder air already gripping the far north of the UK and is set to move further down the country.

The Met Office‘s long-range forecast for the period of Thursday, November 18, to Thursday, November 27, reads: “Colder conditions, already affecting the far north of the UK are likely to extend south to affect all pasts through the early part of the period.

“Initially we may see some less cold conditions with some cloud, rain and possibly hill snow affecting parts of the west.

“It is as this clears later Tuesday that the colder conditions will extend south, bringing some snow showers into northern parts, and the first frosts of the season for many parts of the south.

“Later in the period there is increasing uncertainty, but a trend towards more changeable conditions is possible, with some rain or showers in places, and perhaps some hill snow at times in the north. Temperatures overall likely to return to near-average.”

Full list of the 19 counties affected according to WX Charts 

• Highland
• Moray
• Aberdeenshire
• Perth and Kinross
• Stirling
• Argyll and Bute
• Fife
• Scottish Borders
• Dumfries and Galloway
• Northumberland
• County Durham
• North Yorkshire
• Derbyshire
• Nottinghamshire
• Greater London
• Hertfordshire
• Buckinghamshire
• Essex
• Kent