The first significant snowfall of the winter is set to arrive in Wales on Friday, though it is not expected to be as bad as that in December last year.
The Met Office says the south Wales valleys, the hills of mid Wales, the Black Mountains and the Brecon Beacons are likely to be worst hit.
It has upgraded snow warnings into Friday morning, warning of over 10cm (4in) of snow on higher ground.
Meanwhile, rail delays caused by a lightning strike have been cleared.
The Met Office has warned that heavy rain overnight is likely to turn to snow early on Friday.
BBC Wales meteorologist Derek Brockway said: "It's still coming but don't panic - the snow won't be anywhere near as bad as last December.
"Some disruption is likely but not everywhere will have snow. In fact we're in for a real mix of rain, hail and snow.
"Whether you get snow will depend on where you live and how high you are above sea level."
The Met Office has issued an amber warning which means be prepared, plus a map showing where most of the snow will fall.
A yellow [be aware] warning remains in place in some areas.
Mr Brockway added: "After midnight the rain will turn increasingly to sleet and snow with temperatures around freezing or just above with a north-easterly breeze.
"So first thing tomorrow a mixture of rain and snow. During the day the rain and snow will move away. It will brighten-up but with wintry showers."
While the wintry weather continues, police are advising drivers to ensure they have plenty of fuel in the tank, fully charge their mobile phones before setting off, and to carry warm waterproof clothing, food, water and a torch.
Rail passengers across much of south Wales faced continued delays and disruption from first thing on Thursday following a double lightning strike early on Wednesday that damaged signals on the Cardiff to Bridgend mainline.
The fault was fixed on Thursday afternoon and normal timetables were resumed in time of the evening rush hour.