Snow chaos as ambulance crashes and drivers are stranded during Britain's minus 8C Big Freeze - with four inches of rain and 70mph winds on way for the weekend

Motorists were trapped in blizzard conditions and drifts while an ambulance overturned in heavy snow as the big freeze continued to bring chaos to Britain.

Police, gritters and tractors went to help trapped drivers in a major rescue operation on the A9 in the Highlands yesterday when vehicles became stuck in the snow.

High winds and drifting snow made the road impassable and efforts to reach them and help them to safety took several hours. The road’s snow gates were closed at Helmsdale and Dunbeath and police advised people to avoid travelling in the area.

It comes as temperatures fell to -8C (18F) in West London, Oxfordshire, Dorset and Hampshire early this morning at the start of another day of sub-zero conditions.

Stormy weather will follow this Sunday with 4in (100mm) of rain and 70mph gusts on the way. But a big 20C temperature swing will then sweep away the Arctic chill and make parts of southern England as mild as the French Riviera by early next week.

An ambulance crashed off the A98 and overturned in heavy snow in Aberdeenshire yesterday

A tractor battles through snow drifts on the A9 at Caithness in the Highlands yesterday

A commuter crosses London Bridge on a freezing morning today as temperatures remain low

The Trafalgar Square fountains in London remain frozen this morning amid the big chill

A thick frost covers a car amid sub-zero temperatures in Greenwich, South East London, today

Bear Scotland – which manages Scotland’s trunk roads – shared pictures online of gritters battling the elements to clear drifting snow from the A9.

Last night, Police Scotland said: ‘The A9 between Helmsdale and Dunbeath remains closed due to high winds and drifting snow making the road conditions impassable.’

Several other roads, including stretches of the A836 and A897, were closed.

An ambulance also crashed off the A98 and overturned in heavy snow yesterday in Aberdeenshire. No one on board is thought to have been hurt in the accident.

This weekend, Atlantic frontal systems are due to sweep in, with temperatures initially rising to 11C (52F) in South West England tomorrow.

And by Monday and Tuesday, daytime highs of up to 15C (59F) are possible in southern England.

Benson, in Oxfordshire, which was England’s coldest place on Monday night into Tuesday, falling to -8.3C (17F), is set to reach 13C (55F) during the day by this coming Tuesday, a difference of over 21C.

Britain’s highest temperatures early next week, under the milder air, are set to be on a par with those in Nice, on the south coast of France.

Strong winds and heavy rain are set to accompany the milder weather, however, and a warning for gales has been issued covering the western half of the country on Sunday.

An amber weather warning was in force for the Highlands, Western Isles, Orkney and Shetland yesterday as forecasters said four to eight inches of snow could fall.

An ice warning is in place for western parts of the country this morning which expires at 10am

More than 350 schools remained shut. Around 15,000 pupils in the Highland Council area were affected, and all schools in the Northern and Western Isles, as well as most of those in Aberdeenshire, were closed.

Yellow alerts for snow and ice remain in effect across Scotland today, with the Met Office warning wintry showers could bring disruption to transport and travel.

A warning covering northern Scotland has been extended east into the Grampian region and across the Northern Isles.

The warning is in place until 3pm today, while a similar alert across Scotland’s south, including Glasgow and Edinburgh, expires at 12pm.

Elsewhere today, yellow warnings for ice are in place for much of Northern Ireland and the western coast of England and Wales until 10am.

Overnight temperatures in Scotland again fell below freezing, with data indicating that the mercury dipped to -10C in Eskdalemuir, Dumfries and Galloway, at around 8pm last night.

However, the mercury climbed upward in the region from then on, with the same village sitting at -1C at 5am this morning, as per preliminary Met Office data.

From tomorrow to Monday the weather is forecast to turn milder, with wet and windy conditions expected through the weekend and into next week.

The heaviest rain is expected on Sunday – with 30mm to 50mm falling widely and the potential for peaks of 80mm to 100mm over hills, the forecaster said.

Milder conditions will also result in the thaw of lying snow.

A yellow weather warning for rain has been issued for Sunday and Monday, covering most of the country, with a yellow wind warning issued for parts of Scotland.

Met Office deputy chief meteorologist David Hayter said: ‘Conditions will stay cold on Friday but a change in weather type is on the way, bringing milder air for the UK during the course of the weekend.

‘This change will initially be relatively benign in terms of weather impacts, with a dry Friday and start to Saturday for many in the south of the UK.

A wind warning for gusts of up to 70mph in western areas has been imposed for Sunday

A wind warning for gusts of up to 70mph in western areas has been imposed for Sunday

Forecasters expect up to 4in (100mm) of rain could fall in some western areas on Sunday

The strongest winds hitting on Sunday into Monday could bring gusts of up to 70mph

‘The Atlantic influence will then introduce some wet and windy weather, with a deep area of low pressure approaching from the west on Sunday.

‘While detail is still being worked out, we expect windy weather for many and some heavy rain in the west and so we’ve issued warnings for Sunday for wind and rain.

‘Watch out for updates to these warnings on Friday and Saturday as the forecast develops.’

Scotland may not enjoy the dry spell experienced by much of the country, with showers continuing on Friday and into Saturday.