Don’t just “put the forks into winter,” warn climate scientists, even if there’s a little taste of spring this spring and next week after a deadly cold snap. Round 2 of winter may be on the horizon.
“As Yogi Bera described, ‘It’s déjà vu all over again,’ with the polar vortex and its influence on our weather,” said Judah Cohen, a VERISK atmospheric and environmental research scientist.
“It’s a very complicated and rapidly changing situation, but I believe that it will come down to rinse, lather, repeat.”
This means a repeat of record low snow levels and warm temperatures in December.
That was followed by a repeat of the record cold that was felt across much of the US in early January when wind chills dropped as low as 60 below.
“Cold is likely to return to eastern North America by mid-February, an area where cold snaps are shorter,” Cohen wrote on his blog about the polar vortex.
Rest after the first round of winter
First comes the warmth, but don’t let it tempt you to cancel your ski vacation or put down the snow shovel.
Map showing the Polar Vortex that could affect eastern North America in February. X/Judah Cohen
“For the first half of January, the polar vortex tripped and fell rotten there, moving south. We’re having an Arctic outbreak,” Cohen explained to FOX Weather on Tuesday.
“But now, it’s coming back together, say, and, it’s a very tight rotation, a polar vortex rotation. All the cold air is retreating back towards the North Pole, and we will have a milder end to January.”
A polar vortex is a group of strong winds that surround the North Pole. A steady, steady rotation of winds keeps the arctic air locked in place.
“The cold will likely return to eastern North America by mid-February,” shared Cohen. X/Judah Cohen
When the wind slows and becomes unstable, similar to a peak, the vortex shakes and falls south to the US and Europe, according to Cohen.
“We’re probably going to see a record warm, like we had in December,” Cohen said in the near term.
“But I think then, often when you have this warming of Canada, the polar vortex then tends to transition into a very large disturbance called a sudden stratospheric warming or stretching event, like a rubber band (pulling cold air south).”
A polar vortex is a group of strong winds that surround the North Pole. AP
Weather changes in the stratosphere, the inner layer of Earth’s atmosphere about 19 miles above the surface, lead to weather changes people feel at the surface for about two weeks.
Round 2 of winter is coming
Sudden stratospheric warming triggered the January Arctic blast. The air in the stratosphere warmed by 55 degrees over six days, writes Amy Butler of NOAA’s Chemical Sciences Laboratory. That slows down the polar vortex.
People walk across the Brooklyn Bridge during a snowstorm on Saturday, Jan. 29, 2022, in New York. AP
“That’s what we had in January that brought arctic air, and I think there’s a good chance that will happen again in February,” Cohen said.
“So look for a soft pattern. I don’t think it’s the end of winter. I think it’s not a pattern break, but I think a relaxed pattern.”
This means another Arctic blast and the return of widespread snow.
“I think in the time frame of the second week of February and maybe even mid-February, the polar vortex unfolding becomes more likely,” Cohen said.
“This should help end the very mild pattern across North America. The intensity and duration of the cold weather associated with the unfolding polar vortex remains to be determined.”
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Source: thtrangdai.edu.vn/en/
