Despite a winter blast of sub-zero temperatures and bitter winds, the blanket of snow that greeted residents in parts of Scotland and Northern England this morning has moved only hesitantly southwards during the day.

Late morning snow showers had been forecast across the south of England and Wales, with temperatures ranging between 0C and 3C (32 to 37F).

But although flurries have been reported as far south as Brighton, most of the country has seen light sleet rapidly turning into sludge.

Meanwhile, up to 20cm (8in) of snow in areas of Eastern Scotland and North East England have wreaked havoc on the roads. A driver died when his BMW slid off the A90 and down a 30ft embankment north of Dundee. Part of the A1 in Northumberland was closed temporarily after cars became stuck in the snow. Hazardous driving conditions were also reported in North Yorkshire, where there have been around 30 car collisions.

The first cold snap of the new year comes after strong easterly winds from Siberia sent temperatures tumbling yesterday, and the Met Office issued a weather warning covering the entire country.

"There will be frost and ice all over the country, and we are likely to see some flurries of snow," said Helen Chivers, from the Met Office. "We could finally have a white winter almost anywhere in the country because the temperatures will be low enough."

But Brendan Jones, a forecaster for MeteoGroup UK, said the snow in the south would be "very patchy in nature" and would soon turn to drizzle.

The Highways Agency issued a warning to drivers this morning, urging them to check the forecast and road conditions before setting out.

It advised motorists to pack warm clothes, food, water, boots, de-icer, a torch and a spade in their cars.

Hundreds of the agency's gritting trucks have been out all night, working to limit the travel chaos, and the RAC was this this morning bracing itself for a record number of breakdown calls.

It was also feared the weather could bring about further disruption for rail travellers in a week already plagued with delays and service cancellations due to overrunning repair work on both the West Coast Main Line between London and Scotland and London's Liverpool Street station.

Network Rail, which runs the West Coast line, said today that it had snowploughs, heaters and staff on standby ready to patrol the tracks.

Temperatures are expected to rise again by the weekend, with some areas reaching as high as 8C by tomorrow.