The polar vortex looming over Siberia has generated the coldest temperature on Earth so far this year, and forecasters say it could make its way to Canada as early as February.
“We’re showing a large area of all of British Columbia, all of the prairies, the Northwest Territories, the Yukon and as far as northwestern Ontario as colder than normal for the month of February,” said David Phillips, head of Environment. from Canada. meteorologist, he told CTVNews.ca in a phone interview on Tuesday. “I think it’s a direct result of the southward descent of the polar vortex.”
A weather station in Tongulakh, Siberia, recorded a temperature of -62.4 C on January 1. On February 14, a pocket of frigid arctic air hung over northern Russia. For reference, that temperature is only 0.3C of the average temperature on Mars; cold enough to freeze exposed skin in seconds. It is the coldest temperature Russia has recorded in two decades.
Under ideal conditions, Phillips explained, polar vortices remain over the north and south poles, held up by their own powerful rotations and strong polar jet streams that circle counterclockwise, or west, around Earth’s upper latitudes to the north. and the south.
In the northern hemisphere, the polar jet separates the polar vortex from warmer temperate air to the south. When the vortex holds its shape and remains concentrated over the pole, it is considered a strong vortex. Sometimes, however, warmer air from the south is drawn north over the vortex and plunges into the vortex from high in the atmosphere, displacing cold air.
When this happens, the entire vortex can come off the pole, or parts of it can leak or break off and drift toward lower latitudes, toward lower latitudes. Europe, North America and Asia.
Although the polar vortex is concentrated in the stratosphere, Doug Gillham, a meteorologist for The Weather Network, said it tends to bring cold air into the troposphere wherever it goes.
“It’s way up in the atmosphere, several kilometers up, but it’s generally associated with the cooler air in the hemisphere,” he told CTVNews.ca in a phone interview on Tuesday. “So where we live, when the polar vortex shifts away from the pole, it often brings cold air with it.”
WHEN COULD THE POLAR VORTEX ARRIVE IN CANADA?
By now, Gillham said, the entire vortex has shifted so that most of it hangs over northern Russia. However, it is likely that it will start to change again at the end of January.
“What we have right now is the biggest part is over Siberia, and there’s been unprecedented cold air associated with that,” he said.
When cold weather hits Canada in February, Gillham said it will be because changes in the jet stream cause the polar vortex to dissipate and reform over western Canada, replacing warm air that has settled over the country. in the last weeks.
“We’ve had a powerful jet stream over the North Pacific and it’s been flooding almost all of North America with warm air from the Pacific Ocean,” he said.
“The jet stream is going to change in a way that it will stop flooding the continent with warm air from the Pacific, and we will start to see air from the Arctic drain to the south. And so our winter vacation is coming to an end.”
According to weather network, While western Canada and the prairies can expect a burst of cold weather soon, major cities in eastern Canada are on track to see their warmest winter on record. The weather agency reports that Halifax has experienced an average temperature of 1.5C so far this winter.
For southern Ontario and Quebec, Gillham said cold air from the northwest and warm air from the southeast could collide to create volatile weather when the polar vortex shifts again.
“Being the battle zone means we’re going to get a more active storm track, which means a lot of messy weather systems, the chance of heavy snow, but also the chance of ice and rain.”