Motorists are warned of potentially difficult driving conditions today with up to 15cm (6in) of snow forecast to fall on Scotland’s highest roads.
The first widespread snow of the autumn could also see wet snow down to lower levels, including in Glasgow and the south west.
A Met Office yellow - “be aware” - severe weather warning is in force from 3pm until 10am tomorrow for much of western and central mainland Scotland.
Up to 8cm (3in) of snow is expected to fall across areas above 200m, which include major routes such as as the A702 south of Edinburgh and the M74 in South Lanarkshire.
However, double that amount could hit the A9 around the Drumochter and Slochd summits between Perth and Inverness, and on the A82 through Glencoe, which are above 300m.
A Met Office spokeswoman said: “Rain will turn to snow in places later on Tuesday and into Wednesday morning.
“This could bring accumulations of 4-8cm across some hilly areas of northern England and Scotland, largely above 200-300m, with as much as 15cm possible above 300-400m.
“Please be aware of the potential for difficult driving conditions in some areas.”
The agency said snow would peter out across Scotland overnight but may fall in the Pennines, with up to 10cm (4in) to low levels in parts of Yorkshire and north-east Midlands.
Temperatures last night dipped to -3C at Eskdalemuir in Dumfries and Galloway and -2C at Loch Glascarnoch, north west of Dingwall.
However, it was colder in England, reaching -5C in parts of central England - the lowest yet this autumn.
The Lecht snowsports centre, at 630m on the Aberdeenshire/Moray border, was covered with snow today, but officials said there was not enough for it to open yet.
At the CairnGorm Mountain resort, which has pistes at up to 1,000m, staff reported the "first significant dump of snow" yesterday with further snowfalls forecast all week.
BEAR Scotland, which maintains the 1,500 miles of trunk roads north of the Central Belt, said it had 56,600 tonnes of salt ready to tackle snow and ice.
It said staff would use detailed forecasts and information from 86 roadside weather stations to decide where to send its 94 gritters and patrol vehicles.
Managing director Brian Gordon said: “Tuesday night into Wednesday morning is likely to see the first forecasted snow and sleet across some higher-up routes in Scotland.
“As ever, we ask members of the public to ensure their vehicle is well maintained, that they pay close attention to local and national media and information to help plan journeys during inclement weather and that they carry equipment to help themselves should conditions deteriorate.”