Winds reaching speeds of 100mph are expected on Scottish mountains over the next two days.
The Met Office has issued an amber warning for the Highlands, Western and Northern Isles and Strathclyde for Thursday night and Friday morning.
Snow showers and lightning are also forecast for Scotland’s northern and western mountains as a vigorous depression passes over the area.
The amber warning means people should be prepared for disruption to transport and power supplies and there may also be structural damage to buildings.
The Mountain Weather Information Service said extreme winds will develop after dark, with a severe wind chill on mountain tops. Whiteout conditions will hit munros from time to time. It will feel like –17C on the hills in the windy conditions.
A lesser yellow warning for strong winds has been issued for the rest of Scotland and the northernmost part of Northern Ireland.
Police Scotland said anyone travelling during late Thursday and early Friday should take extra care.
Superintendent Stewart Carle said: “During this period of extreme weather, Police Scotland road policing crews will be patrolling the road network in order to keep people safe.
“Please be aware of the advice being issued, and drive with extra caution and use common sense in challenging situations.”
Police said people should ensure that they and their vehicle are adequately prepared for the conditions. Make sure you have sufficient fuel and supplies such as warm clothing, food and water in the event you are delayed for several hours. Charge your mobile phone and plan your route as well as alternative routes.
Coastlines are likely to be at threat from large waves, the Met Office said.
Avalanche risk on Thursday is likely to be considerable on northern to eastern aspects in all five areas covered by the Scottish Avalanche Information Service.