- The polar vortex split will help cause temperatures to plummet and potentially set the stage for some snowstorms.
- A recent strong “sudden stratospheric warming” event has caused the vortex to weaken.
- “Things are really setting up for an exciting period for cold and snow,” one meteorologist says.
Ready for some serious cold? Way up over the North Pole, the polar vortex is about to split, and a piece of it could be paying a visit to the central and eastern U.S. within the next week or two, forecasters said.
This will help cause temperatures to plummet and potentially set the stage for some snowstorms, AccuWeather said. After an initial chill later this week and over this coming weekend, even more cold air is set to invade after that.
Though the vortex temporarily split last week, “there will be another more robust split of the polar vortex at the end of this week,” meteorologist Judah Cohen of Atmospheric and Environmental Research told USA TODAY on Monday.
What does that mean for us down here in the U.S.?
“I do expect that eventually winter weather will become more active across the U.S. post-MLK Day” on Jan. 18, Cohen added.
Another meteorologist, Todd Crawford of the Weather Co., told Bloomberg on Sunday that “things are really setting up for an exciting period for cold and snow.”
The polar vortex is a large area of cold air high up in the atmosphere that normally spins over the North Pole (as its name suggests). It usually keeps the coldest air locked up in the Arctic.
When the polar vortex is “strong,” cold air is less likely to plunge deep into North America, Weather.com meteorologist Jonathan Erdman said. The stronger the polar vortex, the milder our winter is. (This is what happened last winter.)
However, when the polar vortex weakens or even splits, as it’s forecast to do later this week, it allows frigid air to escape and push southward toward the U.S., AccuWeather said.
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The polar vortex is synonymous with extreme cold and snow, the Capital Weather Gang said: “Pieces of the vortex broke off and swirled southward during the infamous winter of 2013-14, when Chicago turned into ‘Chiberia’ and heavy snow fell from Washington to Boston,” the Gang said last week.
A recent strong “sudden stratospheric warming” event – when temperatures in high up in the stratosphere over the Arctic spike suddenly – has caused the vortex to weaken: “The polar vortex draws strength from the large temperature difference between the tropics and the polar region,” Cohen told USA TODAY.
“When warm air rushes the North Pole in a sudden stratospheric warming event, the temperature difference slackens and can even reverse and so the polar vortex weakens and moves south,” he said.
It’s not especially unusual for the polar vortex to break down, according to Popular Science. Although this one is particularly powerful, “stratospheric warming events happen about every other year,” Andrea Lopez Lang, an atmospheric scientist at the University at Albany, told Popular Science.
Meanwhile, a significant winter storm could be just around the corner, meteorologists say.
“The weather pattern setting up across the East suggests the potential for a big storm to develop in the Plains and potentially impact the mid-Atlantic or Northeast around Jan. 18 or 19,” said AccuWeather long-range expert Paul Pastelok.
Should the storm slow down, it could hit the Washington, D.C., area on Inauguration Day, Jan. 20, AccuWeather said.
2021-01-11 11:19:28
