The Yellow warning, which covers most of the country, including Glasgow, says that plunging temperatures will cause ice that eventually gives way to snow after showers.
Aberdeen, Dundee and Edinburgh are not thought to be affected by the warning, which runs from 3am until 6pm on Wednesday, as it skips much of the east coast of the country.
The Met Office warns that roads and railways are likely to be affected by snow, reminded commuters that longer journey times by road, bus and train are probable.
The Chief Forecaster’s assessment read: “2-5 cm of snow is expected to accumulate in places above 200 m. Some snow is also possible to low levels at times, mainly overnight.
“Snow is expected to become confined to higher routes, mainly above 250m, on Wednesday afternoon.”