A Met Office snow warning for south-east Scotland has been upgraded to amber as Storm Christoph brings in “challenging weather conditions”.
The alert covers the Borders, East and West Lothian and Midlothian until 08:00 on Thursday.
A wider yellow warning for snow is in place for southern Scotland with another for the north east.
The Met Office said up to 30cm (12in) of snow was possible on the highest ground covered by the amber alert.
Police Scotland has urged people to avoid travelling in the affected areas.
Chief Superintendent Louise Blakelock said: “Government restrictions on only travelling if your journey is essential remain in place and with an amber warning for snow, please consider if your journey really is essential and whether you can delay it until the weather improves.
“If you deem your journey is essential, plan ahead and make sure you and your vehicle are suitably prepared by having sufficient fuel and supplies such as warm clothing, food, water and charge in your mobile phone in the event you require assistance.”
The amber warning for snow covers a slice of Scotland from south of Edinburgh to close to the Scotland-England border and is valid overnight from Wednesday into Thursday.
Much of the rest of southern Scotland has a yellow alert for snow in place.
In the north east of Scotland, a snow and ice warning was in place for most of Wednesday with a wider snow warning from Thursday until 12:00 on Friday.
Heavy rain is expected to affect the extreme north east and Orkney.