UK weather: 'Dangerous' winter deluge to dump half a foot of snow as Britain freezes in Arctic snap

Worst hit will be Scotland and northern England where weather models suggest the big freeze will dig into the festive season.

Government forecasters warn to expect delays on roads and travel networks, power cuts and mobile phone outages.

Met Office deputy chief forecaster Tom Crabtree said: “Wednesday to Friday has the greatest potential for impactful weather, with multiple warnings in force.

“Overnight, temperatures could fall to minus ten, with a significant wind chill from a strong northerly wind making things feel even colder.

“Snow showers are expected to extend south through Wednesday and into Thursday, mainly affecting north facing coastal areas.”

The heaviest downpours will be to the north, with half a foot of snow likely to settle in parts, he warned.

By mid-week, southern regions could be under a couple of centimetres as temperatures plunge below freezing, he added.

He said: “On hills in parts of Northern Ireland, the northeast of England and Scotland, five to ten centimetres of snow could fall and accumulations of 15 to 20 centimetres are possible above 300 metres.

“Although many places will see plenty of sunshine, daytime temperatures will be well-below average, with a widespread frost setting in during the evening, especially in sheltered areas."

The UK Health Security Agency (UKHSA) has upgraded a yellow cold-weather alert covering northern England to a more serious amber.

It warns of a ‘rise in deaths’ in the over-65s, increased pressure on health services and cold-weather impacts to younger people.

Katherine Crawford, chief executive of Age Scotland said: “Older people might find it increasingly difficult to get out and about safely, leading to increased levels of loneliness and isolation.

“Blocked or icy roads and paths can affect someone’s ability to collect shopping and prescriptions, get to doctors’ appointments, visit friends and family, and attend social groups and clubs, without the fear of falling and needing to go to hospital.

“We urge everyone to check in on older family, friends and neighbours during periods of extreme weather.”

Weather warnings for snow and ice remain in force across Scotland and the north until the end of the week.

A change in wind patterns will bring milder conditions to the south, although parts of the country could remain in the freezer.

Jim Dale, meteorologist for British Weather Services and co-author of ‘Surviving Extreme Weather’, said: “Low pressure comes in during the middle of the week, and that is going to bring the greatest risk of snow to Scotland and the Highlands.

“We are looking at temperatures in minus double figures in exposed parts, with lows at freezing elsewhere.

“At the weekend, a shift in wind direction will bring milder conditions to the south, but the snow and cold is going to hang around in Scotland and the north, and here it could take a while to recover.”