Northern New York weather has been rather boring as of late with gray skies, spittles of snow and daytime temperatures hovering around the freezing mark. But a wobble in the polar vortex has been detected.
Prepare to have things shaken up.
The “polar vortex” phrase has gained traction in recent years, mostly for the images of the winter weather whirlwind it conjures up, something like what the fictional supervillain Mr. Freeze might devise. But the polar vortex is always with us, or rather above and below us. It’s a large area of low pressure and cold air surrounding the north and south poles. The term vortex refers to counter-clockwise flow of air that helps keep the colder air close to the poles.
“It’s a name that gets peoples’ attention, but to meteorologists, it is sort of a misnomer because the polar vortex exists all the time,” said Michael J. Fries, warning coordination meteorologist at the Buffalo office of the National Weather Service.
But when the polar vortex is disrupted, changes can be expected. A recent disruption has occurred.
“When the polar vortex essentially gets disturbed, it basically wobbles and cold air comes southward to North America, Europe and Siberia depending on how the vortex breaks up,” Mr. Fries said.
Meteorologists like Mr. Fries find evidence of polar vortex disturbances when they witness “sudden stratospheric warming events.”
“We started to get signs that one was occurring a couple of weeks ago,” Mr. Fries said on Tuesday. “We were watching these charts. The temperatures in the high latitudes in the stratosphere started to go way up.”
It takes time for the effect of that temperature increase in the stratosphere over the north pole to affect the lower part of the atmosphere and at ground level.
“Once it does, you generally start to see cold air get shoved southward from the pole because of what we like to call a blocking pattern that generally sets up,” Mr. Fries said.
The disruption concluded a few days ago.
“We’re probably on the order of two weeks until the really cold air comes, maybe a bit less,” Mr. Fries said. “Our weather models in the very far extending are starting to see cold air bottling in Canada and coming down. Our climate models are seeing that cold air not only coming down, but sticking around.”
Those cold temperatures are relative to what temperatures we’re experiencing now. The temperatures also depend on where the cold air created by the vortex comes from.
“If the cold air were to come down the front range of the Rockies and then travel east, usually it would moderate somewhat by the time it got here,” Mr. Fries said. “However, if the cold air came plunging south across Hudson Bay and straight into the Great Lakes, it would come here more unattenuated and it would probably be colder.”
Generally, Mr. Fries said, the shift in the latest polar vortex will create temperatures about 18 degrees Fahrenheit colder than where we are now.
“You’re probably talking about highs in the upper teens or something like that,” he said. “We don’t see ridiculous cold right now. But indicators seem to point to cold air arriving and sticking around.”
Mr. Fries said it’s notable that we didn’t have a polar vortex, or a “sudden stratospheric warming event” all last winter. But there was one in early spring of 2020.
“There was a big one and it lasted quite a while,” Mr. Fries said. “As you recall — April and May, it snowed all the time. Last spring was the only time we had a warming event.”
It can be difficult to link snowfall forecasts to disruptions in the polar vortex.
“Chances are, just based on the temperatures we’re dealing with, there will be lake effect,” Mr. Fries said. “However, sometimes these continental air masses can be very dry, so that the result of lake effect isn’t real substantial.”
But then again, it may all depend on which way the wind blows.
“If you’re in Watertown, and the cold air comes down from the plains and travels east, you end up with a westerly flow over Lake Ontario, and end up with snow,” Mr. Fries said. “Whereas, if it comes from the northwest, it would push the lake snows down into Oswego County or whereever.”
Many eyes will be on Buffalo, and its weather, Saturday night as the Bills battle the Baltimore Ravens in a divisional NFL playoff game at New Era Field in Orchard Park.
“Right now, it looks like there will be lake effect snow showers around with temperatures falling into the 20s by game time,” Mr. Fries said.