The polar vortex swirling over Siberia has generated the coldest temperature on Earth so far this year and, according to meteorologists, is likely to head to Canada in early February.
“We’re showing a large area of all of British Columbia, all of the Prairies, the Northwest Territories, the Yukon, and even northwestern Ontario as being colder than normal for February,” Environment Canada chief meteorologist David Phillips told CTVNews.ca in an interview. phone on Tuesday. “I think this is a direct result of the southward sinking of the polar vortex.”
A weather station in Tungulakh, Siberia, recorded a temperature of -62.4°C on January 14 when a pocket of frigid Arctic air swept over northern Russia. For reference, it’s only 0.3 degrees Celsius warmer than the average temperature on Mars; Cold enough to freeze exposed skin in seconds. It is the coldest temperature Russia has recorded in two decades.
In ideal conditions, Phillips explained, the polar vortices remain over the north and south poles, held in place by their strong spin and powerful polar jet streams that spin counterclockwise — or west — around Earth’s high latitudes to the north and south.
In the northern hemisphere, the polar jet separates the polar vortex from warm, temperate air in the south. When a vortex retains its shape and remains centered over the pole, it is considered a strong vortex. Sometimes, however, warmer air from the south creeps northward over the eddy, and dips down into the eddy from higher up in the atmosphere, displacing cooler air.
When this happens, the entire vortex can deviate from the pole, or parts of it can escape or break off and drift to lower latitudes – to Europe, North America and Asia.
Although the polar vortex is concentrated in the stratosphere, Doug Gilham, a meteorologist for The Weather Network, said it tends to bring cold air into the troposphere wherever it goes.
“It’s fine in the atmosphere, many kilometers high, but it’s generally associated with the coldest air in the hemisphere,” he told CTVNews.ca in a phone interview Tuesday. “So down where we live, when the polar vortex moves off the pole, it often brings cold air with it.”
When could the polar vortex hit Canada?
Right now, Gilham said, the entire vortex has shifted so that the bulk of it is hovering over northern Russia. However, it is likely to start shifting again towards the end of January.
“What we have now is the largest chunk over Siberia, and there was some record-breaking cold air associated with that,” he said.
When cold weather comes to Canada in February, Gilham said it will be because shifts in the jet stream are causing the polar vortex to dissipate and reshape over western Canada, replacing warm air that has settled over the country in recent weeks.
“We had a strong jet stream over the North Pacific Ocean that was blanketing almost all of North America with mild air from the Pacific Ocean,” he said.
“The jet stream will change in a way that will prevent the continent from being flooded with temperate Pacific air, and we will start to see the Arctic air drain further south. And so our winter vacation is coming to an end.”
to me weather network, While western Canada and the prairie expect a spell of cold weather soon, major cities in eastern Canada are on track to see their warmest winter on record. The Met Office reports that Halifax has seen an average temperature of 1.5°C so far this winter.
For southern Ontario and Quebec, cool air from the northwest and warm air from the southeast can collide to create choppy weather when the polar vortex changes again, Gilham said.
“Being a battle zone means we’ll get a much more active storm track, which means a lot of chaotic weather systems, the potential for heavy snow, but also the potential for snow and rain.”