Temperatures will plummet over the next 24 hours with lows of -15C forecast in exposed regions and snow ‘possible anywhere’. Most at risk, however, will be Scotland, parts of northern England and the West Country as icy winds blow in from the Arctic.
It will travel across Scandinavia, and through the Norwegian Trondheim Fjords in a ‘carbon copy’ of the pre-Christmas chill which left swathes of Britain buried under snow, and was dubbed the ‘Troll from Trondheim’.
Jim Dale, meteorologist for British Weather Services, said: “A northerly airflow will come into Britain this week, and again will come through Scandinavia and Norway, so we are looking at a similar set-up to the cold snap and snow before Christmas.
“In effect, this is going to be a repeat of the Troll from Trondheim, although it will be a mini version as we do not expect it to last as long or have as wide an impact.
“But in terms of the meteorological set-up, it is more or less the same. It is a carbon copy of the change in airflow which brought the very cold snap in December.”
Freezing air will sweep in from the North Pole from today with the main risk of snow through the first half of next week.
Eastern and south-eastern regions may dodge the worst of the Arctic deluge, although snow is possible widely, Mr Dale warned.
He said: “The cold push will move south during the course of Sunday.
“The risk of snow will be on Monday and Tuesday, and this will be mainly to the north although there is a risk of wintry showers across the southwest and even though eastern and south-eastern regions are not showing up as being in the firing line, snow here can’t be ruled out.
“People are going to notice the drop in temperatures with lows of -15C possible in the most exposed regions of Scotland, but even further south, we could see -7C.”
Met Office meteorologist Aidan McGivern said: “Our winds will start to come with more of a north-westerly flavour with colder weather coming in from the northwest.
“Colder and fairly showery weather will come from the north and the northwest.
“It is not going to be as cold as we started the winter, but it is going to be cold enough for snow in some places.
“On Sunday, there will be frequent showers coming in from the north and the northwest, where they will be falling as rain, sleet and hail, but as snow certainly over the hills.”
The Met Office has issued alerts for ice and up to six inches of snow across northern Scotland through the week.
Government forecasters warn of ‘frequent wintry showers’ with significant accumulations in a short time.
Those heading out on the roads are warned to take care with icy stretches triggering treacherous driving conditions.
Eastern regions will see the brightest skies through the start of the week although everywhere will be cold, he added.
He said: “The brightest skies will be towards the east, and it is going to feel cold wherever you are in the wind.
“That weather from the north continues to affect us as we start off next week, you wouldn’t rule out snow anywhere but it’s coming in the form of showers, and predominantly any accumulation will be over the northern hills, but not exclusively.”
James Madden, forecaster for Exacta Weather, said: “The snow is likely to affect the north at first through the start of the week, but it could travel to southern regions.
“We could see some weather warnings more widely as the risk of heavy accumulations builds.
“The main risk will be from some heavy and persistent snow, which with the wind will bring blizzard conditions to parts of the country, and with that will be hazards on the roads and transport networks.”