Key Takeaways
- A polar vortex is expected to bring extremely cold temperatures to most of Canada over the coming days
- The polar vortex is a band of strong westerly winds that form in the stratosphere above the North Pole every winter, enclosing a large pool of extremely cold air
- The cold blast is expected to last throughout the weekend, with temperatures plunging to -40 to -50 C in some areas
- The polar vortex is becoming a more common occurrence, and is linked to climate change
- The harsh winter conditions are expected to continue until early February, but may return later in the month
Introduction to the Polar Vortex
The polar vortex is a severe weather phenomenon that is expected to bring extremely cold temperatures to most of Canada over the coming days. Environment Canada has issued weather warnings for most of the country, with a "high or moderate impact level" cold blast expected to last throughout the weekend. The daytime average temperature in Toronto is expected to be -12.5 C, with the wind chill making it feel like -23 C, alongside wind gusts hitting up to 41 km/h. Temperatures are expected to plunge to -40 to -50 C in the Prairie provinces and -40 to -48 C in northwestern Ontario.
What is a Polar Vortex?
So, what exactly is a polar vortex? According to the U.S. National Weather Service, the term polar vortex has only recently been popularized, but has always existed as a severe weather event. The term "vortex" refers to the counterclockwise flow of air that helps keep the colder air near the Earth’s poles. The National Weather Service also states that throughout the winter season in the northern hemisphere, the polar vortex will expand, sending cold air southward. The National Oceanographic and Atmospheric Administration in the U.S. states that an arctic polar vortex is a band of strong westerly winds that form in the stratosphere between about 10 and 30 miles above the North Pole every winter, which enclose a large pool of extremely cold air.
Impact of the Polar Vortex
The polar vortex is expected to have a significant impact on the weather across Canada. Global News chief meteorologist Anthony Farnell said that the extent of this system is what has meteorologists paying attention. "Given how widespread it is, that’s what makes this rather remarkable, seeing how most of Canada is into this deep freeze," he said. "We haven’t seen this in a couple of years." The polar vortex is becoming a more common occurrence, and is linked to climate change. Farnell said that the country has had its share of deep freezes in this past November and in January 2024 in Alberta. "It seems we are getting more extremes, whether it’s warmth or in this case cold, and that is a byproduct of climate change," he said.
Regional Weather Patterns
For a considerable part of the country, this has been a tough winter already. "From Saskatchewan, Manitoba, Ontario and Quebec, this has been a colder, snowier winter than normal," Farnell said. "For the Maritimes it has been a lot of back-and-forth — there’s been warmups, rain and then it gets cold. On the west coast, it’s been almost an easier winter; there hasn’t been a flake of snow in Vancouver yet." The winter storm system is set to bring potentially catastrophic ice and snow amounts across large swathes of the United States from Friday through Sunday. That system is set to clash with the polar vortex currently causing a deep freeze across much of Canada, with significant snowfall for regions including Ontario and Quebec starting Sunday afternoon and into the evening as it moves east.
Outlook for the Rest of the Winter
The harsh winter conditions are expected to continue until early February, but may return later in the month. "The arctic air that’s been around will be replaced with more Pacific air," Farnell said. "That arctic air will retreat back to the north and reload." However, Farnell said that the country is not out of the woods yet. "Right now, it is unloading the arctic air, and it is going to moderate by early February and we may see another blast later in the month," he said. "We are not out of the woods yet." The polar vortex is a reminder that the weather can be unpredictable and severe, and it’s essential to stay informed and prepared for any weather-related events.