Warning of high winds and snow forecast for Scotland
Forecasters have warned of high winds and blizzard conditions affecting large parts of Scotland during Monday and into Tuesday morning.
The Met Office has issued amber and yellow warnings.
Several schools in the Western Isles were closed and about 200 homes were without power. Ferry sailings across Scotland were disrupted.
Transport Scotland said the Multi-Agency Response Team would be monitoring conditions.
The bad weather has been forecast until 09:00 on Tuesday.
Transport Minister Keith Brown said difficult driving conditions were expected.
He said the latest Met Office forecast for frequent and at times heavy snow, combined with gales force winds, "will mean a testing journey for many this evening and also, crucially, during rush hour tomorrow".
Mr Brown added: "As always we are playing our part by delivering winter service treatments to our roads, but sudden weather changes can occur, and the impact the weather can have from one location to the next can be very varied."
Ferry operator Caledonian MacBrayne reported disruption to 23 sailings. Some services were cancelled, including the Uig to Tarbert and Tobermory to Kilchoan sailings.
CairnGorm Mountain ski centre said it was closed on Monday because of storm force to hurricane force winds.
The centre said wind speeds at the summit of Cairn Gorm were between 70 and 80mph.
The six schools shut in the Western Isles include Barra's Castlebay primary and secondary.
About 200 homes in Lewis and Harris were without power.
The Met Office warned of heavy, squally wintry showers affecting many parts of Scotland through much of Monday.
It issued an amber "be prepared" warning for the Highlands, Western Isles, south Scotland, Lothian, Tayside, Fife and Strathclyde.
A yellow "be aware" warning was issued for other parts of Scotland, including the north east and Northern Isles.
Winds could gust to gale force, it said.
It has forecaste 10 to 20cm of snow on higher level routes, with drifting and temporary blizzard conditions.
In the mountains it said conditions would be "atrocious".
The Met Office said there could be could five to 10cm of snowfall, with some drifting, at lower levels.
Scientists at Lews Castle College UHI have been measuring what they described as "extreme" wave heights in the sea off west Lewis.
Arne Vogler, a senior research engineer and principal investigator at the Hebridean Marine Energy Futures project, said hurricane force gusts had also been recorded.
He said extreme wave heights with averages of 14m (45ft) and maximum waves of 23m (75.5ft) had been recorded.
Mr Vogler said: "For context, average wave heights depend highly on the time of the year. In the winter we quite often see heights of 3-5m, where in the summer this is often down to 0.5-2m."
The engineer said the waves were energy rich.
He said that if it was possible to harness the power of waves hitting the entire length of the Western Isles' Atlantic coastline on Monday, they would equate to 120 nuclear power stations on maximum electricity generation output.