The polar vortex — a band of low-pressure air spinning around the North Pole in the stratosphere — is typically stable through early winter. This year it is behaving in a way meteorologists have never documented.

According to AOL, the disruption now being observed is the earliest sudden stratospheric warming event ever recorded, an event in which stratospheric temperatures jump 50–70 degrees Fahrenheit in just a few days and cold air trapped over the Arctic spills toward the mid-latitudes.

Andrew Charlton-Perez, professor of meteorology at the University of Reading, told AOL that such disruptions usually happen toward the end of winter, in January or February, making the November timing highly unusual.

Judah Cohen, a climate scientist at MIT, said a weakened vortex releases cold air southward, raising the risk of snowstorms or ice storms.

The practical consequence of the record-early breakdown is a cold signal for the United States. Per AOL's reporting, the polar vortex disruption is expected to bring chilly temperatures to the U.S. by Thanksgiving week, as the wobble displaces Arctic air toward lower latitudes.

Cohen cautioned that a weak polar vortex in November by no means dictates the rest of the winter — it could make the start of winter colder, but its influence may not last much longer.

Tracking the vortex is now easier for weather watchers: Severe Weather Europe runs a Polar Vortex Explorer updated four times a day, drawing on 132 ensemble members from ECMWF, AIFS and GEFS, and showing live wind at 10 hPa and 60°N compared with every year since 1958.

What makes this winter genuinely novel is the collision of two major climate forces.

A strong El Niño is forecast for this winter, and AOL reports the two drivers may work with or against each other: if the vortex stays strong and circular while El Niño dominates, both favor mild weather and reinforce each other; if the vortex stays weak and wobbly, it favors cold, setting up a battle in which whichever force wins decides the pattern.

Experts told AOL it is too early to say how the so-called super El Niño will interact, since only about 45 such vortex events have ever been observed. Cohen put it bluntly: we have never had a polar vortex disruption of this magnitude and a super El Niño, making this uncharted territory.

Severe Weather Europe's live toolkit lays out the diagnostic evidence behind the story.

Sudden stratospheric warmings are officially defined by a wind reversal to easterly at 10 hPa, about 30 km up, around the 60°N circle — and its ensemble panel shows the share of members reversing winds, with above 30% worth watching and above 60% making an SSW likely.

Strong, sustained pulses of wave activity (heat flux at 100 hPa) are the classic warning sign, typically slowing the vortex one to two weeks later.

The site also compares the current winter against analog winters since 1958, while cautioning that a similar start does not decide the winter: since 1958, about half of all winters had at least one major SSW, and the analogs did not predict whether one followed.

It also added a monthly long-range outlook for Winter 2026/2027.