Met Office chief meteorologist Jason Kelly said: “Storm Bert starts to arrive overnight on Friday and into Saturday, initially over Northern Ireland.
“As we go through the first part of Saturday morning, it will start to show its hand across Scotland, north Wales and northern England, with the potential for some heavy snowfall, especially over higher ground.”
He warned that rapid melting of lying snow over the weekend may lead to flooding in some areas.
Storm Bert is expected to be a “multi-hazard event” due to the potential impact of combining heavy snow, rain and wind.
Supt Vinnie Fisher, deputy head of road policing, said: “All road users should consider if they really need to travel in adverse weather.
“Listen to media broadcasts for updates, follow Transport Scotland and the Met Office on social media and share information with others.”
Scottish government agency Transport Scotland said roads may be affected by deep snow, particularly over higher routes, and some rural communities might be cut off.
Interruptions to power supplies and telephone networks could also occur.