A winter storm blamed for at least two deaths and commuter chaos in southern Ontario is bringing high winds and heavy snowfall to Quebec on Friday as it sweeps toward the Maritimes.

Environment Canada has issued a winter storm warning for regions stretching from Ottawa into southern Quebec as well as all of New Brunswick, Nova Scotia and Prince Edward Island.

"The problem with this winter storm is we've seen everything — snow, freezing rain, rain, ice pellets and high winds," said CBC meteorologist Nick Czernkovich.

The storm, which knocked out power to roughly 80,000 people in Ontario overnight, brought 27 centimetres of snow to the Montreal area in just 12 hours, Czernkovich said.

Friday was a snow day for most students in the greater Montreal region, as all major school boards called off classes for the day. Many flights were cancelled at Pierre Elliott Trudeau International Airport.

The combination of heavy snow, freezing rain and winds brought down power lines and trees, Czernkovich added.

"We all look at the snowfall, but we can't underestimate the effect of winds."

Part of the storm is sheering off toward northern Ontario as the main body heads eastward and is expected to hit the Atlantic provinces later on Friday.

In Nova Scotia, high winds were forecast for the shoreline late Friday, with some areas expected to be hit with gusts of up to 100 km/h.

Thousands without power

Meanwhile, across Ontario, thousands of residents woke up Friday morning in homes without power.

Hydro One spokesman Daffyd Roderick told CBC Newsworld about 80,000 households and businesses had no electricity.

Hydro crews were alerted to 25 snapped poles on Thursday afternoon, but the main obstacle facing power crews is gaining access, he said.

"There's only so much we can do until Mother Nature does her work, and then we can set about repairing … when conditions are safe out there."

By Friday afternoon, officials said power had been restored to 40,000 customers.

Meanwhile, police in Toronto closed a downtown section of Front Street after chunks of ice were seen falling from the CN Tower and other buildings.

"It's like shrapnel when it hits the ground," a police officer told CBC News.

Few parts of southwestern Ont. "unscathed"

The power failures have affected portions of southwestern Ontario from Strathroy and Walkerton to Newmarket and the GTA.

"Very few parts are unscathed today," Roderick said, adding the hardest-hit areas may have to wait between three and five days to see the situation restored to normal. 

Wind gusts of up to 82 km/h were recorded at Toronto Island Airport.

Many Ontario roads are flooded or slick with ice, and more freezing rain and snow on Friday could make driving conditions just as treacherous as the previous day, when the intense storm was blamed for the deaths of two children.

Police said the children — seven-year-old Anita Hiebert and her six-year-old brother, Pancho — died Thursday when a car and a truck collided on an icy, snow-blown road near the town of Listowel, northwest of Kitchener. The children's mother, Christina Hiebert, is in critical condition in a London hospital.

Police and tow trucks responded to hundreds of other crashes across southern Ontario, as blowing snow and ice pellets created slippery conditions and poor visibility.

With files from the Canadian Press