A Polar Vortex Is Expected To Hit Eastern Canada & Temps Could Drop To -20 C

Eastern Canada is bracing for some of the coldest air of the season, as a wave of Arctic chill is set to plunge temperatures from Ontario to Nova Scotia this week, including Southern Quebec. The frosty grip, extending all the way down to the Gulf of Mexico, follows a blizzard in far Northern Canada, where Nunavut saw temperatures plummet into the -40s.

The frigid air mass is part of a polar vortex, a phenomenon that intensifies in winter, wrapping around the Arctic and occasionally sending shivers down to lower latitudes. According to The Weather Network, instability is resulting in a pronounced dip — or 'trough' — out of the Arctic, signalling a brief but intense cold spell for millions of Canadians.

From blizzard to bitter cold

Nunavut recently experienced a major snowstorm, with record-breaking winds and power outages. As remnants of the storm intensify near Baffin Island, the eastern half of Canada is set to experience a steep drop in temperatures. Manitoba is already feeling the chill, with forecasts predicting lows of -20.

By Tuesday, northern Ontario will see temperatures more than 10 degrees below normal for this time of year, extending down to the Gulf of Mexico. Toronto could have its first subfreezing day of the season, with highs just below zero.

The big chill

The sudden cold snap could also generate significant "lake-effect snow" across the Great Lakes, meteorologists say. Southern Ontario could see over 15 cm of snow accumulation, while the warmer lakes temper the Arctic air's impact.

Central and eastern Ontario, along with southern Quebec, won't be as lucky, facing the full force of the cold with night-time lows possibly reaching the negative teens.

The Maritime provinces won't be spared either, with forecasters watching Halifax for its potential first subfreezing day. Fortunately, the burst of Arctic air is not expected to linger. The frigid air mass will be short-lived, paving the way for a return to seasonal or slightly warmer temperatures in Ontario, Quebec, and the Maritimes by week's end.

Frosty forecast

In Montreal, Environment Canada forecasts mainly cloudy skies on Tuesday with a 40 percent chance of flurries in the afternoon. Temperatures are expected to remain steady near -1 C, with a wind chill making it feel closer to -11 C. The night will bring cloudy periods and a low of -7 C.

On Wednesday, the city should see a mix of sun and cloud, with the high hovering around zero degrees. Cloudy conditions will persist into the night, with the temperature remaining at zero. The forecast for Thursday, calls for cloudy skies throughout the day and a high of 5 C. The night is expected to stay cloudy, with a low of 4 C.

Heading into Friday, rain is predicted with a high of 5 C. The night will likely see periods of rain or snow, dipping to a low of -3. Saturday will have a mix of sun and cloud with a daytime high of 1 C and nighttime lows around -6 C under cloudy periods. Meanwhile, Sunday will be cloudy with a 60 percent chance of flurries and a high of 0 C.

While this week's polar vortex-induced cold spell should be brief, its impact marks a dramatic start to the winter season in Canada.