An Arctic air mass continues to cast a deep freeze over large patches of Canada this morning, plunging many parts of the country into the negative double digits and bringing cold air and wind chill warnings.

CBC News meteorologist Jay Scotland said it will be a busy weather day for two primary reasons: Snow for Atlantic Canada, and potentially dangerous wind chill values across much of the country.

Blizzard and snowfall warnings were in effect along the west coast of Newfoundland and southeastern Nova Scotia, where drivers were warned to give themselves ample time to reach morning destinations due to blowing snow and poor visibility. Southeastern Newfoundland looks likely to be the hardest hit by the storm, Scotland said, with about 15 centimetres expected to fall around the vicinity of St. John's and the Avalon.

There are also weather woes forecast in northern Alberta, southern Manitoba, northern Ontario and central Quebec, due to very low wind chill values.

Temperatures in Manitoba are forecast to be particularly harsh.

Homeless shelters opening up emergency beds

In Winnipeg, a Tuesday high of –21 C drives home the severity of its wind chill warning. The extreme chill is forecast to be as low as –40 C in the morning, and daytime highs over the next week aren't expected to get any warmer than –20 C.

City of Toronto officials are urging residents to call the municipality's 311 hotline if they spot homeless people who may be caught out in the bitter cold.City of Toronto officials are urging residents to call the municipality's 311 hotline if they spot homeless people who may be caught out in the bitter cold. (Tony Smyth/CBC)

Staff at the city's homeless shelters have been scrambling to open up emergency beds for those caught out in the bitter cold.

The bone-chilling Toronto temperatures may have already claimed one man's life downtown overnight. A homeless man was found without vital signs and hypothermic on Markham Road in the Scarborough neighbourhood. He later died in hospital.

Environment Canada forecast Toronto temperatures late Monday and into early Tuesday morning to dip into –13 C without the wind chill, and a high of –11 C on Tuesday during the day. With the wind chill, it will feel like –25 C in the city. There were no special weather statements or warnings issued for Toronto, but motorists in the Barrie, Collingwood and Hillsdale regions further northwest were told to brace for snow squalls and near-zero visibility on the roads from blowing snow.

Parts of Northern Ontario are under wind chill warnings due to the Arctic air mass and gusts of around 15 km/h, which could bring wind chill values as low as –55 C in the morning, though daytime heating is likely to bring that up closer to a still-blistering –45 C.

Ottawa will experience a high of –15 C with temperatures falling to –19 C in the afternoon.

A high of –17 C is forecast for parts of Quebec, with a wind chill in the morning making it feel closer to around –30 C. Extreme wind chills were in effect late Monday night for the Abitibi regions, courtesy of a northwest flow from Eastern Quebec bringing strong winds and cold air. Environment Canada issued a warning saying the uncomfortable conditions would spread into Central Quebec and persist in the St Lawrence Valley throughout the week.