High above the North Pole, the polar vortex, a fast-spinning whirl of frigid air, is doing a weird shimmy that may soon bring cold and snowy weather to the Eastern U.S., Northern Europe and East Asia for weeks on end, meteorologists say.
While it’s not unusual for the polar vortex to act up, this particular reconfiguration — wandering around and possibly splitting in two — may be tied to climate change in the rapidly warming Arctic, said Judah Cohen, director of seasonal forecasting at Atmospheric and Environmental Research in Massachusetts, part of Verisk Analytics, a risk-assessment company. “Expect a more wintery back-half of winter here in the Eastern U.S. than what we had in the first half,” Cohen told Live Science.
The Arctic is heating up faster than any other region in the world. As a result, sea-ice cover there is shrinking — in September 2020 and December 2020, the Arctic sea-ice cover shrunk to its second-lowest and third-lowest minimum on record for those months, respectively, according to the National Snow and Ice Data Center. The warmer-than-usual temperatures in the Arctic are likely throwing the polar vortex out of whack, Cohen said… During the winter, a jet stream of air that keeps the polar vortex in place sometimes weakens, allowing the vortex’s chilly air to extend southward…
Disruptions to the polar vortex are key for forecasts, as about two weeks after they happen, the troposphere gets a wallop of weird weather, which can last for weeks. Because of this week’s polar vortex disruption, “there’s indications we’ll see some colder weather within two weeks… in the Eastern U.S., Northern Europe and East Asia,” Cohen said.