Residents in Ontario were being advised Thursday to pull out the shovels, prepare their snowblowers, fill their gas tanks and stock up on salt and windshield washer fluid to prepare for a major snowstorm that’s on its way.

The province will be slammed with a double whammy of an Alberta clipper and a Texas low, said Environment Canada senior climatologist David Phillips.

Forecasters said a wide swath of the province could see anywhere between 15 to 30 centimetres of snow over 36 hours, with winds gusting to at least 60 kilometres an hour. Environment Canada issued snowfall warnings and special weather statements from Windsor and Niagara Falls in the west to Ottawa and Gatineau, Quebec in the east to Parry Sound-Muskoka.

While many parts of the region were already seeing flurries Thursday morning, the biggest dump was expected to start by the evening and continue through Friday. The heaviest snow is expected to occur during the Friday morning rush hour along the Highway 401 corridor from London to the Greater Toronto area and down through Niagara and the Golden Horseshoe.

Heavy and blowing snow was forecast for the Friday afternoon commute, the worst of it for communities on the western end of Lake Ontario. Some freezing rain and ice pellets are possible over the extreme southwest.

Provincial police were urging people not to drive but if they have to go out, motorists should slow down and leave extra following room between vehicles.

For Toronto, it could be the biggest snowfall in a single storm in years.

"We're out of practice here," Phillips told CTV's Toronto affiliate CP24.

"You'd have to go back about five years to find a snowfall of say more than 16 centimetres back to December 19, 2008," said Phillips.

Last year, Toronto had a record low amount of snowfall -- at the most in one day five centimetres, he added.

GTA prepares for disruptions

As of 8:45 p.m. Thursday, 64 of 708 daily arriving flights had been cancelled at Toronto's Pearson International Airport. A statement on the airport’s website urged travellers to check the status of their flights before coming to the airport on Thursday and Friday.

Meanwhile, most school boards around the Greater Toronto Area said they would wait until about 5:30 a.m. on Friday to announce any disruptions to bus routes and possible school closures. The boards often cancel buses but still keep the schools open.

The Toronto-area schools that have confirmed they’ll be closed Friday include:

  • Crestwood Preparatory School and Crestwood School
  • Leo Beack Day School, including north and south campuses in Toronto and Thornhill
  • Wishing Well Montessori school in Markham

The City of Toronto issued an extreme weather alert, urging homeless people to take shelter indoors. The city also made another 172 shelter spaces available. The city is also increasing its overnight street outreach where workers will take homeless people to warm places.

Dump trucks were busy dumping big piles of salt brought in from Windsor at Toronto city works yards in preparation for the wicked weather. Workers were also mixing brine -- a mixture of salt and water -- and transferring it into trucks that then headed out to spray roads before the storm hit. The brine makes it easier to plow the road.

"Brine, what it does is it allows the salt to react immediately upon application on the roadway as opposed to waiting for the snow to actually kick in and start the process with the salt,” Hector Moreno, an acting manager of road operations in Toronto, told CTV News.

"It actually binds to the pavement so when we are ready to send the plows it just basically comes right off," said Moreno.

Motorists should keep an emergency kit in the trunk of their vehicle that includes a blanket, non-perishable food and water, salt or sand, a shovel and scraper, said the Canadian Red Cross.

Shovelling snow has been known to cause heart attacks, the Red Cross said. The agency recommends taking breaks and staying hydrated.

Ontario farmers were being urged to be prepared for possible power outages that could affect livestock by having a generator handy. Farms.com also recommended famers have extra water and feed on hand for their animals.

The blast of snow is a mix of an Alberta clipper and a trough moving ahead of a Texas low that is tracking northeast across Oklahoma to Illinois on Thursday then following a path near the south shore of Lake Erie on Friday.

Forecasters expect the storm to reach parts of Quebec by Friday before heading to New Brunswick and Nova Scotia over the next couple of days.

South of the border, much of New England is also being warned to prepare for a major storm. As much as 60 centimetres of snow could fall on the region, which has seen very little of the white stuff this winter.

The U.S. National Weather Service says Massachusetts, northeast Connecticut and Maine, are expected to feel the brunt of the storm. It’s expected to start Friday morning, and continue into Saturday as it moves past New England and upstate New York, the National Weather Service said.

A coastal flooding watch also is in effect for some shoreline communities in Massachusetts, Connecticut and Long Island.

With files from The Canadian Press and The Associated Press