A winter storm is hammering eastern Ontario and southern Quebec, while a second low-pressure system has prompted Environment Canada to issue weather warnings in the Prairies.

The storm in Eastern Canada has caused major headaches on roads in the national capital region, where snow began falling around noon.

Forecasters were calling for 10 to 15 centimetres of snow in the area. By 5 p.m. ET, Ottawa police said they had responded to more than 100 collisions and were advising motorists to adjust their driving to slippery conditions.

A fire tanker also went off the road on Highway 416 near Ottawa on Friday.

Police said none of the dozens of collisions led to serious injuries.

The wintry weather has also affected flight schedules in Quebec and Ontario. A number of flights at airports in Toronto, Ottawa and Montreal have been cancelled or delayed.

The storm hit Montreal Friday afternoon and was expected to blanket the area with between 15 and 20 centimetres of snow, while Eastern Quebec could see up to 30 centimetres by Saturday morning.

“Quebec City and east, tomorrow it will be really, really bad,” said René Héroux, a meteorologist with Environment Canada.

Héroux said motorists in eastern Quebec can likely expect road closures into the weekend as snowfall makes driving hazardous.

Conditions around Toronto

Downtown Toronto was spared from the worst of the storm, experiencing only rain and high winds with temperatures hovering around zero. But areas north and west of Highway 401 were expected to get between five and 15 centimetres of snow by Friday evening.

Environment Canada had issued snowfall warnings for the Greater Toronto area Thursday, but CBC weather specialist Jay Scotland said the storm system warmed as it moved east across Lake Ontario, causing more rain than snow to fall south of Highway 401.

To the north, there was snow from Georgian Bay east through the Kawarthas and into Eastern Ontario. Windsor in southwestern Ontario received at least five centimetres of snow, while London and Hamilton were expected to see up to two centimetres.

After a rainy day on Thursday, the Maritime provinces are looking at blizzard warnings as the storm sweeps through the region this weekend.

In New Brunswick, Environment Canada was forecasting that blizzard conditions could hit Miramichi and communities in the Acadian Peninsula on Saturday. The blizzard could bring up to 30 centimetres of snow, along with strong winds. Whiteout conditions are expected to last at least four hours, said CBC meteorologist Kalin Mitchell.

Western Canada

Environment Canada issued a winter storm watch for much of southern Saskatchewan as a separate low pressure system moves east. The agency said a major winter storm would hit most of southern Saskatchewan beginning on Saturday. Snowfall amounts of 10 to 15 centimetres are expected.

Similar amounts of snow are forecast in the Edmonton area by Saturday evening. A snowfall warning was in effect for a swath of Alberta from Grande Prairie in the west to Lloydminster in the east.

Vancouver was told to expect about five centimetres of snow, while parts of the B.C. Interior could see closer to 15 centimetres.

The Canadian Avalanche Centre expanded an avalanche warning for B.C. on Friday. The warning lasts through Monday.

"The clear, dry spell covering the province in early February had a weakening effect on the surface of the snow at that time," said Karl Klassen, manager of the CAC’s public avalanche warning services, in a news release.

"Now that surface is buried and left us with a very complex upper snowpack, with a number of weak layers. Conditions are very tricky to manage right now. If you’re going into avalanche terrain, you need local knowledge, extensive experience and training," he said.