Weather forecasters have warned that wind speeds could reach 80mph as gales batter parts of Scotland.
The Met Office issued a severe weather warning for the Western Isles, Shetland, the south west and parts of Ayrshire.
An emergency planning group on the Western Isles has urged people not to leave their homes or travel unless absolutely necessary.
The A9 in the Highlands has also been badly hit by drifting snow.
Police said the road southbound at Dalwhinnie was closed because of minor accidents and was restricted to a single lane northbound at Tomatin due to a jack-knifed lorry.
The A9 from the Drumossie Brae south was described as treacherous with whiteout conditions and gale force winds.
Northern Constabulary added that the A835 Ullapool to Dingwall road was also affected by drifting snow and winds.
The BBC's 23 Degrees team is blogging on the storm, describing what has caused it and monitoring its progress.
There have been reports across the country of property damage, fallen trees and loose debris, including a chimney which has fallen from a property on Kilmarnock Road, Glasgow.
Strathclyde Police advised drivers not to travel unless their trip was essential.
The Western Isles Emergency Planning Co-ordinating Group said people should remain indoors.
A spokesman said: "High speed winds are currently buffeting the islands and are expected to continue until late tonight and into the early morning.
"Essential travel only should be undertaken although key workers should report as normal."
All schools on the Western Isles closed early and public transport services were being reduced, the islands council said.
Overnight ferry sailings to and from Shetland have also been cancelled.
The Scottish Environment Protection Agency (Sepa) has also issued flood alerts, with up to 50mm of rain expected in some parts in the next 48 hours.
The stormy conditions have resulted in the Hrossey, from Aberdeen, and the Hjaltland, which was due to leave Lerwick for Aberdeen via Orkney, being cancelled.
The shipping forecast has also warned of possible hurricane force 12 winds for the Hebrides. Gusts of 63mph have already been recorded in Tiree and at South Uist.
According to the Met Office, there could be up to 60mm of rain in the west of the country and higher levels in the coming days.
They have joined Sepa to ensure co-ordination over possible flood risks.
'Manage circumstances'Sepa has issued a number of flood watches for rivers in Argyll, Highland, Tayside, Shetland and around the Forth Valley.
It comes as the Scottish government activated its multi-agency response team after snow was forecast for many areas.
Transport Minister Keith Brown said more than 115 winter vehicles were on hand to respond to the conditions.
He urged drivers to plan journeys and to follow police travel advice.
He added that the Traffic Scotland website would provide regular travel updates.
"Our multi-agency response team has been activated ahead of the forecast snow to manage circumstances as they unfold, and ensure a co-ordinated approach to dealing with any issues as they arise," he said.
"In addition we are well prepared with over 455,750 tonnes of salt secured or on order across Scotland - compared to the 545,600 tonnes used from the start of winter to date."
The multi-agency team, which includes operating companies, the police, Traffic Scotland and ScotRail, was set up following the last severe winter weather.
