Britain’s official weather forecasters have issued a red alert as blizzards and strong winds are due to hit part of Britain tomorrow.
Upland areas of south Wales are expected to be most affected up to 30cm (12 inches) of snow on mountains and hills, with whiteout conditions, the Met Office said.
Lower areas can expect to see between 10 and 15cm.
An amber warning is in place for other parts of Wales, western England, the Midlands and central and southern England, as well as Northern Ireland where accumulations of 20cm or more over the hills and 10 to 15 cm are expected.
A Met Office spokesperson said: “A red warning means that we need to take action to keep ourselves and others safe from the impacts of the weather. Widespread disruption to travel and other services is likely.
“All of us should consider changing our plans and avoiding dangerous areas.”
Forecasters said that although snow will fall over most areas, the far west, including Cornwall and extreme western parts of Wales are expected to see the snow turning to rain, with the rain replacing snow across other parts of southwest England during the day.
Andy Page, Met Office chief forecaster, said: “The snow is expected to be heaviest during Friday morning across Wales and the southern half of England.
“Clearly there is the potential for significant disruption to people’s plans. We should follow the advice of the emergency services and local authorities to help keep ourselves, our families and our communities safe in light of the forecast.”
Darron Burness, head of the AA’s severe weather team, said: “With the outlook remaining cold, drivers need to be prepared for possible disruption.
Steve Crosthwaite, head of the Highways Agency’s national traffic operations centre, said: “We advise drivers to check road conditions and the Met Office weather forecast before they set off and during severe weather to consider whether their journey is essential.
They may want to delay their travel until conditions improve and to allow our winter fleet the chance to treat the roads.
The Met Office spokesperson added: “Over the weekend we will see less severe conditions but further outbreaks of rain, sleet and snow are possible in places. The snow that has fallen will be slow to melt and ice will continue to be a risk, especially at night.”