Polar vortex shifting southward due to spiking temperatures around North Pole

Rising temperatures in the North Pole are causing parts of the polar vortex to split off and move southward, leading to the possibility of a particularly harsh winter in the U.S., Europe and Asia. 

The polar vortex, which the National Oceanic and Atmospheric Administration (NOAA) defines as “a large area of low pressure and cold air surrounding the Earth’s North and South poles,” generally remains strong and stable, as it did last winter. 

As reported by The Washington Post, when it remains stable, cold air stays within the area over the Arctic, with snow chances much less in the Mid-Atlantic and Northeast regions. 

However, recent stratospheric temperature spikes are raising concerns on the impacts it will cause for weather events in the U.S.

Amy Butler, a research scientist at NOAA’s Chemical Sciences Laboratory, told the Post that stratospheric warming events that knock the polar vortex off balance are triggered by an upward flow of “large-scale atmospheric waves” from the lower atmosphere. 

The stratosphere can then transfer energy in downward-moving waves, leading to blizzard conditions in some areas. 

This happened, for example, in the winter of 2013 to 2014, when broken-off pieces of the polar vortex caused blizzards and heavy snow in cities like Chicago, Washington, D.C., and Boston. 

Judah Cohen of Atmospheric and Environmental Research in Massachusetts told the Post that while he and other forecasters are attempting to analyze the possible impacts of the recent breakage of the polar vortex, “No one is going to care until there is snow in people’s backyards.”

Cohen added that it is still unclear whether the warming will impact parts of the U.S., as similar warming last year did not throw the vortex off-balance enough to lead to a particularly harsh winter. 

The Post reported that stratospheric warming events occur about six times per decade on average. 

Cohen and other experts predict that this year, the stratospheric warming will likely lead to a split polar vortex scenario, with one center over Eurasia, and the other elsewhere. 

According to the Post, Cohen added that while there could be major upcoming snowstorms in the U.S., polar vortex splits tend to concentrate near Europe.