Uh oh. The dreaded polar vortex may be making an appearance very soon

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In 2014, the term “polar vortex” appeared in Canada and the United States as temperatures plummeted.. In some places it was colder than it was on Mars.

Well, get ready to hear more about it. ForecastersMany parts of Western and Central Canada are about to feel the effects of an event that will bring cold weather in the coming weeks. And he may move to Eastern Canada.

“European [model]The latest one looks like a pretty impressive cold pattern,” said Judah Cohen, a climate scientist at the Massachusetts Institute of Technology (MIT).

“The cold will come east of the Rockies… you'll hear about Calgary, definitely Winnipeg.”

Although the term became popular a decade ago, the fact remains that the polar vortex always exists. It’s just that in the north it usually remains high.

The polar vortex is found in the upper atmosphere, especially in the stratosphere. If it's stable, it stays there. However, from time to time in winter it destabilizes and moves further south, bringing cold air to lower latitudes. It interacts with the jet stream in the troposphere where we humans live, and this is what leads to colder than normal temperatures.

“Every two years, there's a disruption of the polar summit. So you get very large warming, like tens of degrees Celsius in a few days, due to the breakup, stretching or disruption of these winds,” said Michael Sigmond, a research scientist at Environment and Climate Change Canada (ECCC).

Two illustrations of the Earth are shown: the first with arrows circling over the north pole, and the second with arrows along a wavy line. — An illustration of what happens when the polar vortex breaks down. Typically, as seen on the left, it remains between 15 and 50 km above the surface and remains in the Arctic. But when it weakens, as seen to the right, it can break down, interacting with winds closer to the surface and carrying cold air to lower latitudes. (NOAA)

Different types of polar vortexes

Not all polar vortexes are created equal, Cohen explained.

One of them is called sudden stratospheric warming, where there is extreme warming in the upper atmosphere, about 30 kilometers above the Earth. This disrupts the flow and carries it south.

“Sudden stratospheric warming is what everyone is most concerned about,” Cohen said. “It can have a big impact, not so much because of the intensity, but because of its duration.”

In addition, there are polar vortexes that separate and those that simply trail down south.

So which one is it?

The jury is still out, he said, although some believe that this will be a sudden stratospheric warming, which, contrary to its name, brings cold air to the south.

“If this does materialize, it will be the earliest event in history,” Sigmond said.

An image of Niagara Falls, most of which is frozen. — The American side of Niagara Falls begins to melt after the polar vortex in early January 2014. (Nick LoVerde/Associated Press)

Interestingly, Sigmond left Toronto for the more temperate climate of Victoria after the 2014 polar vortex cold snap.

“We moved in May, but I always say, oh, that was our goodbye,” he said.

Whether it's sudden stratospheric warming or just a good old-fashioned polar vortex doing its thing doesn't really matter, Cohen said. It will be cold.

But where will it go once it hits Western and Central Canada?

“Is it diving due south or heading east?guard?” Cohen said. “That's probably the biggest question.”