Ready the shovels and snowblowers: parts of southern Ontario are preparing for their biggest snowstorm of the season.
For Toronto, warnings of the wintry blast come as the city has issued its third extreme cold weather alert.
Environment Canada said Sunday a major snowstorm will bring 20 to 30 centimetres of snow to a wide swath of southern Ontario by the time it's over Wednesday afternoon.
"It's possible it could be the most snow we've seen in a storm so far this year, at least for regions outside the snowbelt," said Environment Canada meteorologist Ria Alsen.
The storm is even on Toronto Mayor Rob Ford's radar.
"Extreme cold weather alert in effect. Bundle up Toronto!" he tweeted Sunday.
A vast area from Windsor to Barrie to Cornwall will be buried, said Alsen. Some areas could receive more accumulation and there could be blowing and drifting snow.
A low pressure system originating in Colorado will dip down into Texas on Monday. It will pick up a lot of moisture from the Gulf of Mexico and head towards Ontario in the next couple of days, said Alsen.
Periods of light snow are expected to develop over much of the region Monday night.
Heavier snow will arrive Tuesday night and linger throughout the day Wednesday as the storm tracks northeastward and passes just south of the lower Great Lakes.
A lake effect snow band could also affect areas near the west end of Lake Ontario on Tuesday morning.
Streamers coming off Lake Ontario could give areas from Hamilton to Oakville a bigger wallop of snow.
Windsor to London and Hamilton will see the highest amounts, said Alsen.
The biting cold will add to commuters' misery.
A ridge of high pressure sitting over northern Ontario is pumping cold air over southern Ontario.
"That's the reason the storm could be so strong - the contrast between the warm air and the cold air," said Alsen.
Temperatures across southern Ontario are expected to be colder than normal for the next few days.
While temperatures will warm slightly during the storm, they will still be below normal and will dip down once again after the storm blows through, said Alsen.
The city of Toronto has activated extra support services. More than 100 agencies have been advised and 171 shelter spaces have been added as outreach workers try to convince homeless people to go indoors.
The city activates the alert when temperature plunges to -15 degrees or lower without the wind chill or in extreme weather conditions.
The Canadian Automobile Association advises motorists to avoid the roads or give themselves extra travel time. It also suggests they carry a fully charged cell phone, winter survival kit, extra clothing, blankets, non-perishable food and a candle in case they get stranded.