Winter is about to take a savage parting shot unleashing a possible four-week assault of sub-zero gales and blizzards and wreaking havoc across the UK.
A violent storm system poised to rip into the country on Sunday will drag a swathe of bitter air in from the North Pole pushing temperatures to -14C (6.8F) in parts and kick-starting the late winter mega-chill.
Northern regions are on alert for snowfall through the coming days with southern England and even London at risk later in the month, forecasters warn.
Government weathermen predict unsettled conditions through the rest of March with unusually cold weather to hold out at least until the end of next week.
Long-range experts paint a dreary picture of heavy snow and even blizzards mauling Britain into the start of April.
Exacta Weather’s James Madden said: “Wintry showers will start to spread across much of the country this month, we are looking at a significant snow risk which could reach as far south as London.
“There are some potentially testing conditions building from the middle of the month, we are at risk of a potent late winter blast.
“During this period there is a risk of significant snowfall which could lead to accumulations lasting several days, this could bring some disruption.
“We cannot rule out the risk of snowdrifts through the latter part of this month which although will likely be confined to remote areas of high ground, could hit lower levels at times.”
The freezing blast will be supercharged by a barrage of storm systems lined up to barrel into Britain through the coming days and weeks.
A powerful low-pressure system poised to bear down on the nation on Sunday will arrive with icy-cold winds swept in from the Arctic.
It will open the floodgates to a snow-laden torrent of air from the North Pole which threatens to keep the UK locked in the freezer for weeks.
The weather will take a downwards turn this weekend with torrential rain and gales forecast widely on Saturday and Sunday.
Temperatures will plunge on Sunday as a potentially powerful storm system rips in from the Atlantic, the Met Office warned.
Meteorologist Becky Mitchell said: “There is some uncertainty about this weekend but it is looking unsettled with some potentially deep areas of low pressure bringing very wet and windy weather.
“Everywhere is going to have a chance of seeing wind and rain and in parts of the country there is a risk of gales.
“On Sunday there is one area of low pressure that we have our eyes on and this may bring some cold air in from the north-west which will be Arctic in origin.”
Northern Britain will see the sharpest drop in temperatures this weekend with chilly conditions holding out through next week, she said.
It could be the start of April before the wind and rain dies down and the weather returns to something more spring-like, she added.
She said: “There is a chance we could see snow from this weekend although this is likely to be in northern areas.
“It is going to turn colder towards the end of the week and this cold air will stay with us, particularly in the north, into the middle of the month.
“In the longer term it is going to stay colder in the north and unsettled everywhere for the next couple of weeks.
“At the end of the month we think it will turn a bit more settled.”
Weather charts show a risk of snow in northern parts of the UK this weekend with a nation-wide whiteout possible from mid-month.
Wind-chill temperature charts show feels-like temperatures plummeting to -14C (6.8F) in Scotland by this weekend with the south dipping below zero.
Pressure and wind charts reveal a violent barrage of storms tearing into Britain this weekend and through next week.
Parts of the country face gusts of up to 120km/h towards the middle of next week with risk of travel chaos and floods possible.
The Environment Agency has issued 20 flood alerts and one more serious flood warning ahead of heavy rain this week.
A spokesman said: “River levels are rising and predicted to continue to rise in response to the rainfall.
“Some land and roads may flood and there may be local travel disruption.”