The Met Office has issued new yellow alert weather warnings for snow and ice across most of England, Wales, Scotland and Northern Ireland.
Warnings are now in place for Thursday and Friday.
Existing warnings now include the risk of snow as well as ice, and have been extended south to cover the whole of England except London, the South East and the South Coast.
The whole of Wales is covered as is the eastern half of Scotland and the whole of Northern Ireland.
The warning, which comes into force at 5pm today and lasts through the whole of Friday, reads: "Showers, a mixture of rain sleet and snow, are expected to fall onto frozen surfaces leading to icy stretches forming.
"In addition, a more persistent spell of rain and hill snow is likely to move south across northern England and north Wales during Thursday evening and night.
"This then gradually moving into parts of central and southwest England and southeast Wales on Friday.
"Whilst ice is expected to be the most widespread hazard, snow is likely in places too.
"Snow is most likely to fall over The Pennines, North York Moors and the high ground of Wales and southwest England, with 2-5 cm possible here.
"Elsewhere, whilst some snowfall is possible, accumulations are likely to be slight and temporary. Freezing fog patches are also likely to persist and may prove an additional hazard with areas of visibility less than 100 m at times."
