A RARE red "take action" alert has been issued for part of Wales tomorrow as snow and strong winds hit the UK.
The snow warning covers south-east Wales and says 20-30cm of snow is likely with strong winds causing blizzards and severe drifting. The red alert covers from 3am tomorrow until 9pm.
A yellow "be aware" alert for snow covers virtually all of England, Wales and Northern Ireland - as well as southern and eastern Scotland. Drivers are being warned of widespread snowfall of up to 10cm.
"You should be aware of the risk," said British Met Office spokesman Robin Thwaytes. He said south-west England, south Wales, the West Midlands and central southern England would be worst affected. An amber severe weather warning has been issued.
"You should seriously consider whether to travel - it will be disruptive."
There would be widespread falls of 5 to 10cm with up to 20cm on higher ground. He said some snow would arrive in London but it should not be as disruptive.
Snow will arrive in the south-west overnight, said Laura Caldwell, a forecaster with the MeteoGroup weather division of the Press Association - with heavy winds driving it through Wales and the Midlands by morning.
It will reach East Anglia by lunchtime and arrive in Scotland later "but it will be a lovely day in north-west Scotland."
For much of the UK however, the temperature will struggle to reach a maximum -1C or -2C - and it will feel several degrees colder in string, gusty winds.
There will be some light snow lingering on Saturday - particularly in the East. Maximum temperatures will struggle to climb above freezing, but winds will be lighter.
Steve Crosthwaite, head of the agency's National Traffic Operations Centre, urged drivers to allow more time for morning travel.
"During periods of severe weather we also suggest people consider whether their journey is essential," he added.
"They may want to delay their travel until conditions improve and to allow our winter fleet the chance to treat the roads."
London Fire Brigade urged caution during the " Arctic blast".
Its warning follows two serious fires this week caused by householders taking extreme measures to keep warm.
Yesterday, fire crews were called to rescue an elderly man from a serious blaze in Wembley, north London, which is believed to have been caused by a halogen heater being placed too close to flammable items.
Last week, firefighters battled flames in Fulham, west London, after an electric blanket was left on for the weekend.
British Gas said it was expecting a "huge spike of activity" for its home service engineers this weekend, predicting they would attend around 20,000 call-outs.