A major winter storm is dumping snow, ice pellets, and freezing rain across southern Ontario, shutting down schools, closing offices and grounding flights.

The same storm could dump up to 40 centimetres on Montreal and Ottawa overnight, while the Maritimes can expect a messy morning commute on Wednesday.

Environment Canada has winter storm, freezing rain and snowfall warnings in effect for nearly all of southern and eastern Ontario, southern Quebec, New Brunswick, Nova Scotia and Prince Edward Island.

A separate storm is expected to dump 15 to 25 centimetres on Metro Vancouver.

That brings the total number of people under snowfall or winter storm alerts to more than 20 million, according to The Weather Network chief meteorologist Chris Scott.

“This is peak winter across the country, really,” Scott told CTV News Channel.

Travel snarled in southern Ontario

Southwestern Ontario was the first to be hit on Tuesday morning. London, Ont., faced freezing rain that continued through the afternoon commute.

In Hamilton, Ont., the storm started out as snow in the morning and turned to freezing rain by noon. Ontario Provincial Police reported cars spinning out of control.

In the Greater Toronto Area, a mix of snow and ice pellets snarled morning commutes. Environment Canada expects 15 to 20 cm of snow to accumulate in the GTA between Tuesday morning and into the early hours of Wednesday.

Ontario Provincial Police Sgt. Kerry Schmidt said Tuesday morning that visibility was extremely limited on major highways around Toronto, and conditions were still deteriorating.

“This is a work-at-home kind of day,” he told CTV News Channel.

Hundreds of flights were cancelled at Pearson International Airport on Tuesday. Few flights were taking off or landing from Toronto’s Billy Bishop Airport

Ottawa International Airport was also facing cancellations.

Environment Canada said up to 40 cm could fall in the capital by Wednesday afternoon. Cold weather was also expected to be a significant factor there, with an afternoon high of -11 C feeling more like -22 due to wind chill, creating the risk of frostbite.

“Some advice for Ottawans: Leave work early,” Scott said.

“You don’t want to be out in the snow this evening, because that’s when the storm will be at its peak.”

Quebec and Atlantic Canada

Snow was expected to start falling in Montreal during the Tuesday afternoon commute, with 25 to 40 cm of accumulation expected by the end of Wednesday. Cold conditions were in the forecast, too, with Environment Canada forecasting wind chill values at or below -20 through the day Tuesday.

Montreal largely escaped the school closures and travel disruptions that dotted Ontario’s landscape on Tuesday. Scott said the situation would be different on Wednesday, predicting that Montreal would likely see cancellations then.

The storm system was on track to start dumping snow on the Maritimes Tuesday night. Between 20 and 40 cm of snow was in the forecast for Moncton, N.B., with the precipitation changing over to ice pellets and possible rain or freezing rain Wednesday afternoon. A similar forecast was issued for P.E.I., although snowfall totals there were not expected to exceed 30 cm.

The northern half of Nova Scotia was expected to see 15 to 25 cm of snow and ice pellet accumulation during the day Wednesday. The winter storm warning did not cover Halifax, although that city was expected to receive as much as 15 cm of snow along with ice pellets and significant winds.

Snow from the system was expected to start moving into Newfoundland and Labrador by Wednesday afternoon.

After the storm

Environment Canada senior climatologist David Phillips told CTV’s Your Morning Tuesday that another Colorado low was brewing and could arrive in Eastern Canada by the tail end of the weekend.

Despite that, he said, Canadians should have some reason for optimism that sunny skies may not be far out.

“The dead of winter is clearly behind us in all parts of Canada. There’s more winter behind us than ahead of us – but you can’t write the obituary on winter yet,” he said.

Phillips said longer-range forecasts suggest temperatures will start warming up in March, and perhaps stay warm enough to avoid a repeat of the April 2018 ice storm that left hundreds of thousands of people without power.

“We can see it coming to an end, but we have to be patient,” he said.

Phillips said a prolonged warmup was likely still “several weeks away” for most of Canada. Scott agreed, saying that winter seemed to be “relatively locked in” across the country for another three weeks.

“Whatever the groundhog said, ignore it,” Scott said.