Winds circling the North Pole have slowed sharply this month, the same kind of disruption that in January 2019 split the polar vortex and sent Chicago to minus 23°F, cold enough that rail crews ran flames along the tracks

High above the Arctic, about 20 miles up, a ring of powerful winds normally spins around the North Pole every winter. In early November 2026, those winds did something forecasters had never recorded this early in the season. They slowed almost to a stop, and then briefly reversed.

Disruptions like this one have come before some of the most severe cold outbreaks in recent memory. The best-known example came in January 2019, when the Midwest froze so hard that railroad crews set fires along the tracks to keep trains moving.

What the polar vortex is

The polar vortex is a large area of cold air and low pressure over the Arctic. Its upper part, in the stratosphere, is ringed by strong west-to-east winds that usually strengthen through autumn and winter.

When the vortex is strong, those winds act like a fence, keeping the coldest air locked near the pole. When the vortex weakens, the fence can buckle. Lobes of frigid Arctic air can then spill south into North America, Europe or Asia.

What’s happening this November

At the end of October, the vortex’s winds were close to normal for the time of year. Then they collapsed. Measured at a standard height and latitude, they fell from about 49 mph on October 25 to about 12 mph by November 2. By around November 10, they had reversed direction entirely.

That reversal is the official marker of a major sudden stratospheric warming. It’s a rapid heating of the air high above the pole, which disrupts the vortex. Events like this usually happen between late December and March. This one is the earliest on record, by several weeks.

Forecast models expect the winds to recover quickly, returning to normal strength by the third week of November.

What happened in 2019

The winter of 2018 to 2019 shows why meteorologists watch these events closely. Around New Year’s 2019, a sudden stratospheric warming split the polar vortex into separate pieces.

A few weeks later, at the end of January, one of those pieces of Arctic air plunged into the central and eastern United States. On January 30, 2019, Chicago’s O’Hare Airport dropped to minus 23°F, with wind chills far lower. Schools, businesses and mail delivery shut down across the region.

To keep trains running, Chicago-area rail crews used gas-fired heaters that send flames along the tracks. They keep switches from freezing so trains can change tracks safely. Photos of the burning rails spread around the world and became one of the defining images of that cold wave.

Will this winter be the same?

Not necessarily. A disrupted vortex raises the chances of severe cold, but it doesn’t guarantee it. Where the cold air goes depends on the shape of the disruption and on weather patterns closer to the ground, and sometimes the effects largely miss populated areas.

Timing also matters. When the vortex is disrupted, the effects on surface weather often take two to four weeks to appear, if they appear at all. This year’s event is also expected to be brief, which may limit its impact.

Forecasters say the disruption raises the odds of colder outbreaks into December in parts of North America and Europe. Updated winter outlooks are expected later in November.

How to prepare for a cold snap

Even without a perfect forecast, a few simple steps make sense for anyone in a cold-winter region. Check your heating system before the first deep freeze, and keep spare blankets and a battery-powered light at home in case the power goes out.

Protect pipes in unheated spaces with insulation, and let taps drip slightly during extreme cold. In your car, keep an ice scraper, a blanket, water and a phone charger.

During severe cold, limit time outdoors, and cover your skin. Frostbite can begin within minutes when wind chills fall well below zero. It’s also worth checking on older neighbors and anyone living alone.

A record worth watching

This November’s disruption is already a meteorological first, but its real significance will only be clear in the coming weeks. Meteorologists will be watching whether the cold air high above the pole begins to influence the weather below.

For now, it’s a reminder that what happens 20 miles above the Arctic can shape the winter weather we feel on the ground.