The system is expected to rapidly intensify as it crosses southwestern Newfoundland and moves into central Labrador later Monday.
"Strong winds gusting from 100 to 140 km/h are expected across all of Newfoundland," Environment Canada said in a late afternoon warning.
Blizzard warnings and blowing snow warnings are in effect in several areas of Labrador. Environment Canada said almost 30 centimetres of snow has already fallen over southeastern Labrador. It also said a further 10 to 25 centimetres are expected for central and northern Labrador tonight.
Nova Scotia was hit with snow on Saturday, and it changed into freezing rain and then back into snow on Monday, creating slushy roads for morning commuters.
Environment Canada said there's still a risk of freezing rain and blowing snow in the Halifax region.
Cape Breton isn't escaping unscathed either. "Blizzard conditions can be expected this afternoon and evening in the Cape Breton Highlands," warned Environment Canada.
Prince Edward Island is almost at a standstill as snow and high winds batter the province. Police are telling drivers to stay off the road.
A wind warning is in effect in central P.E.I. through tonight with gusts approaching 90 km/h.
Travel a challenge
High winds prompted Marine Atlantic to cancel ferry crossings on Monday, as a stormy system swept into much of Newfoundland and Labrador.
The Crown corporation had already cancelled crossings that had been set for late Sunday, forcing travellers and truckers to wait until conditions improved.
Winds on the Newfoundland side of the Cabot Strait hit 110 km/h on Sunday. Marine Atlantic said it will update its website when it makes a decision about Monday night's schedule.
Travelling by plane isn't much easier. The departure board at the Halifax Stanfield International Airport is a sea of red with dozens of cancellations and some delays.
Lois Preston said she left Truro, N.S., early Monday morning to catch a flight. Now she has a long wait ahead of her.
"I was to fly out of here this morning at 7:30 and then they booked me for the 9:30, and now I'm waiting for the 6:30," she said.
Many highways around Nova Scotia are slippery. The Confederation Bridge, which links P.E.I. and New Brunswick, is closed to high-sided vehicles, including transport trucks.
In many parts of the East, teachers and schoolchildren at least won't have to travel in the stormy weather because of school closures, including many in Nova Scotia, all on Prince Edward Island, and in Labrador and on Newfoundland's Burin Peninsula.
Government offices and dozens of businesses have closed for the day on P.E.I.
New Brunswick remains mainly unaffected.