There will be a bit of a taste of spring this week and next after an outbreak of deadly cold snaps, but don't “put winter in its place” just yet, climate scientists warn. A second race in the winter could be just around the corner.
“As Yogi Berra said, “It's déjà vu all over again'' about the polar vortex and its impact on the climate, said Judah Cohen, Atmospheric Environment Research Scientist at VERISK. .
“The situation is very complex and changing rapidly, but I believe that ultimately we will end up washing, lathering and repeating.”
This means a repeat of December's record low snowfall and warm temperatures.
Then there was a repeat of the record cold temperatures felt across much of the United States in early January, with wind chills dropping into the low 60s.
“Cold temperatures are likely to return in mid-February in eastern North America, where the cold has been more episodic,” Cohen wrote on his blog about the polar vortex.
Break after the first round of winter
First off, it's going to be warmer, but don't let that stop you from canceling your ski trip or putting away the snow.
“In the first half of January, that polar vortex kind of stumbled, where it got dirty and moved south. There was an outbreak in the Arctic,” Cohen explained to FOX Weather on Tuesday.
“But now we can say we're back to normal and the polar vortex is spinning very tightly. All the cold air is retreating towards the North Pole and we'll have a milder end to January. ”
A polar vortex is a belt of strong winds that orbits the North Pole. The constant steady rotation of these winds holds the arctic air in place.
As the winds weaken and become more unstable, the vortex will wobble just like the crest and move south toward the United States and Europe, Cohen said.
“We're probably going to have record warmth, like December,” Cohen said of the near future.
“But I think that when this kind of Canadian warming happens, the polar vortex will then cause a sudden stratospheric warming or a very large phenomenon called a rubber-band stretching phenomenon (pulling cold air south).” I think there is a tendency to move towards chaos.”
Changes in the weather in the stratosphere, the layer of Earth's atmosphere about 30 miles above the Earth's surface, cause changes in the weather that people experience at the surface in about two weeks.
The second round of the winter season is about to begin.
Sudden stratospheric warming caused January's Arctic explosion. Amy Butler of NOAA's Chemical Sciences Laboratory wrote that stratospheric air warmed by 55 degrees over six days. As a result, the polar vortex winds weakened.
“That's what brought about the arctic air in January, and I think it's likely to be repeated in February,” Cohen said.
“So look for a calm pattern. I don't think it's the end of winter yet. I don't think this is a pattern breaking, but I think it's a relaxing pattern.”
That would mean another arctic explosion and the return of widespread snow.
“I think we're going to see an increased likelihood of the polar vortex extending into the second week of February and even into mid-February,” Cohen said.
“This should help end the very mild pattern in place across North America. The strength and duration of the cold air associated with the extended polar vortex is not yet known.”
