Polar vortex split may bring cold snap to Germany in early November

Polar vortex winds are slowing over the North Pole and may push freezing weather south to Germany in early November. Here’s what forecasters are predicting:

Vortex winds weakening over North Pole

While weather forecasters previously predicted polar vortex winds to weaken in January 2027, NASA forecasts show circulation is already slowing. 

Polar vortex wind speeds are expected to fall from 12,03 meters per second (equivalent to 43,2 kilometres per hour (km/h)) on October 31, to the equivalent of 32,9 km/h on November 1 and 14,9 km/h on November 3.

A strong polar vortex keeps very cold winds over the North Pole, but a weakened vortex can send freezing temperatures south toward Europe and North America. But there is an additional factor at play.

If a pocket of warm air, known as a sudden stratospheric warming (SSW), forms over the North Pole, it can cause the polar vortex to stretch like a tense rubber band and split. This is what ultimately pushes polar air downward and causes an influx of cold air at ground level. 

Vortex split could bring polar weather to Germany

A weakened polar vortex and sudden stratospheric warming over the North Pole could then bring a cold snap to Germany around November 4.

Meteorologist Klaus Marquart told 20 Minuten that a weakened polar vortex has not occurred so early in the winter since records began in the 1950s. The only other years when a vortex split occurred so early were in 1968 and 2025, and then it began almost a month later, on November 28.

So, what is unusual about the polar vortex split forecast is not that it is happening, but that it is forecast to happen so early in the winter. 

The forecast split is expected to be rather weak, meaning that if it does happen, temperatures will rise again shortly after. Referring to current models, Wetter.com expects the split to subside again by November 11.