People in most of southern Ontario, including Toronto, are bracing for an onslaught of wintry weather that may bring more snow to Canada's largest city than any other storm since late 2008.

With snowfall and winter storm warnings in effect, Environment Canada is predicting up to 25 centimetres of snow between Thursday and Friday nights as the storm moves into Canada from the U.S.

The City of Toronto issued an extreme weather alert and shelter employees are encouraging homeless people to spend the night in a shelter during the storm.

Light snow will spread into southern Ontario from Michigan and Lake Huron during the day and the heaviest snowfall will begin overnight, the national weather agency said.

Up to 15 cm of snow is possible by the start of Friday morning’s commute, meaning it could be a slow, messy and dangerous drive to work.

According to Environment Canada, the heaviest snow is expected to occur along the Highway 401 corridor from London to the GTA, so motorists should be prepared for hazardous driving conditions, including poor visibility in blowing snow, if they venture onto the roads.

Toronto’s fleet of plows and salt trucks are ready to go. After clearing expressways and main roads, trucks will clear local roads if the city receives at least eight cm of snow accumulation. Normally, local road plowing is completed 14 to 16 hours after a storm has passed.

The city says it will clear snow from sidewalks on local roads where it is mechanically possible if there is at least five cm of snow accumulation.

In the central core of the city, property owners are required to clear their sidewalks within 12 hours of a storm, the city says.

Storm a 'cowboy kind of an event'

David Phillips, a senior climatologist with Environment Canada, said the province is getting hit by two weather systems - an Alberta clipper and a Texas low - at once.

“It’s really a double whammy,” Phillips told CP24 on Thursday morning. “It’s a real cowboy kind of an event for us.”

Snowfall amounts will likely range between 15 and 25 cm, but some regions along Lake Ontario may receive more than that because of lake-effect snow, Phillips warned.

Phillips said the storm will affect a region from Owen Sound to Kingston and south to London and Niagara Region.

If the forecast is accurate, Toronto may receive its largest individual snowfall in almost half a decade.

The last time Toronto has had a single snowfall of more than 16 cm was Dec. 19, 2008, so people should be prepared to grab a shovel, Phillips said.

“We’re maybe a little out of shape and we’ll put our muscles into good use digging out of this particular one,” Phillips said.

Police urge motorists to drive carefully

Meanwhile, police are reminding people to drive with caution during the storm, but they also urged people not to drive if they don't have to.

Motorists should slow down, leave extra room between vehicles in case they are forced to come to a sudden stop, and be prepared for delays because the snow will likely create a slow commute, police said.

Ontario Provincial Police offered additional tips:

  • Drive with your full lighting system on to help you see and to be seen by others on the road
  • Top up your windshield washer fluid and carry an extra container
  • Travel with a full tank of gas
  • Clear snow off of your vehicle, including the roof, trunk, hood and windows
  • Carry a fully-charged cellphone and a cellphone charger
  • Carry a roadside safety kit that consists of a warm blanket, a winter hat, pair of gloves, a candle for heat in case your vehicle breaks down, matches, a flashlight, snow shovel, dry food that will not freeze, and a small metal can that can be used to melt snow

People who become involved in a collision should remain inside the vehicle and avoid walking on the highway or road.

Airlines are urging customers to confirm their flight status before heading to Pearson or Billy Bishop airports, just in case there are any delays or cancellations.

The snowfall is expected to continue well into Friday as the weather disturbance passes just south of the Great Lakes.

Rain possible next week

Once the storm passes, it appears the GTA is in for a decent weekend.

Environment Canada is predicting sun and a high of -5 C on Saturday, and a mix of sun and cloud and a high of 2 C on Sunday. Rain and a high of 7 C is possible Monday.

People who live in the northeastern U.S. states may not be as fortunate, however.

After the storm leaves a blanket of snow in southern Ontario, it is expected to merge with a weather disturbance along the Atlantic coast and dump as much as 60 cm of snow in New England, Phillips said.

Phillips described it as a "classic" nor'easter with blizzard conditions.

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