Climate: Record disruption of the polar vortex: Is Germany now threatened with an ice winter?

The polar vortex over the North Pole is coming under pressure earlier than ever. Experts classify what this means for our winter, how El Niño plays a role and whether climate change plays a role.

Icebergs in the Arctic Ocean: Stratospheric warming in the North Polar region is coming three weeks ahead of the earliest recorded time to date. Photo: IMAGO/Cavan Images

Berlin. A record is on the horizon over the North Pole: the polar vortex could be disrupted as early as the beginning of November, earlier than ever since measurements began. The huge system of cold, rotating air has a major influence on the weather in Europe.

Forecasts now suggest that the winds in the stratosphere are easing and possibly even reversing. Warm air high above Siberia then pushes the vortex from its usual position above the North Pole to the southwest, to a location between North America and Northern Europe. Experts speak of a rapid and significant disruption and slowing of the stratospheric polar vortex.

Currently the vortex is almost divided into two parts, which are still connected. Meteorologist Kai Zorn described it well: “The polar vortex is doing strange things,” he said in his YouTube forecast. Stratospheric warming in the North Polar region is coming a full three weeks ahead of the earliest time measured so far.

When the polar vortex reaches our weather

The polar vortex is a huge low pressure area in the stratosphere, around 30 kilometers above the North Pole. It forms in fall and winter and, as long as it is intact, traps extremely cold air over the Arctic. It initially has no direct consequences for the weather in Germany.

But changes in the flow can, with some delay, be transmitted to the underlying troposphere, the lowest layer of the atmosphere in which our weather takes place. Meteorologists usually expect ten to 20 days. If the vortex is severely weakened, it can promote cold air incursions in Europe, North America or Russia.

Major Warming

If the polar vortex is disrupted, the stratosphere can warm up significantly within a short period of time. Experts speak of “sudden stratospheric warming” (SSW). When the westerly winds completely reverse at an altitude of around 30 kilometers and become easterly winds, this is called “major warming”. Several weather models see such a reversal in early November 2026. It would be exceptionally early. Whether it will happen, however, remains to be seen. The earliest major warmings to date since systematic observation began at the end of the 1950s occurred on November 28, 1968 and November 2025. The vortex can also split into two centers. It is not scientifically clear whether such a split brings more cold air into the middle latitudes than a simple shift. The consequences vary greatly from case to case.

“All eyes are now turning to a significantly stronger disruption of the polar vortex, which is expected to have a significant impact on the weather in the Northern Hemisphere from late November to December,” writes climate researcher Judah Cohen from the US research company AER on his polar vortex blog.

There are no signs of winter in Germany in the next ten days. From the end of November to December, however, meteorologists see a window of opportunity for the onset of winter, which could be due to the polar vortex disruption.

Cold air intrusion possible, but not a guarantee

It is not clear whether the consequences will be as clear as Cohen expects. Statistically, however, there is something to be said for cold: according to researchers, after around two thirds of major stratospheric warming, the North Atlantic Oscillation turns negative. This pressure pattern over the Atlantic weakens the mild westerly winds and makes cold air incursions and wintry weather in Europe much more likely.

However, this is not a guarantee for winter cold: whether cold air actually flows into Germany depends on the position of the highs and lows over the Atlantic and Europe in the weeks after the polar vortex event. And this is determined by many different factors. The weather is a chaotic system: concrete weather conditions can only be calculated a few days to weeks in advance; the stratosphere only provides tendencies.

Disturbances of the polar vortex occur again and again. The low pressure area usually recovers over the course of the winter before completely dissipating in the spring, as it does every year. This is the second year in a row that the vortex has been disrupted very early. It was also affected at the end of November 2025.

Is climate change weakening the polar vortex?

Some meteorologists are already talking about an increase in disturbances in recent years and therefore believe that an influence from climate change is also possible. From a scientific point of view, however, it is still unclear whether global warming will weaken the polar vortex. “Such an early event is uncharted territory,” says the meteorological forecasting platform Severe Weather Europe.

Observational studies have found more frequent periods of weakness in recent decades, but most climate models assume a weak or even no connection. However, an influence of the currently very strong El Niño in the South Pacific on the weak phase of the polar low is considered conceivable.

Since there is no comparable event in the record of the two weather events coming together, weather experts at Severe Weather looked in climate models for winters in which such an early collapse of the polar vortex occurred during a strong El Niño.

“The winters studied indicate significant cold and snowfall in parts of the United States, Canada and Europe in December and January.” However, the current Super El Niño is working against it and wants to impose a completely different pattern: “Both effects overlap: The cold from the polar vortex could be weakened or even become invisible.”

The renowned Swiss atmospheric scientist Daniela Domeisen from the University of Lausanne (UNIL) confirmed to the Tagesspiegel that stratospheric warming is becoming apparent, although not yet with absolute certainty. However, according to their assessment, it is likely to be rather weak. It was similar last year: the very early warming at the end of November 2025 remained weak, and the consequences for the winter weather on the ground were correspondingly limited.

The stratosphere always has surprises in store for us. Daniela Domeisen, atmospheric scientist from the University of Lausanne

“An event like this would definitely be a record if it happened so early in the winter,” says Domeisen. Since such cases have hardly occurred so far in November, it is difficult to derive a mechanism from this, let alone a trend.

Domeisen also believes that the connection with the current extreme El Niño in the tropical Pacific is plausible, even if the more precise connections still need to be researched.

Will there be a stronger polar vortex disruption?

The current disruption of the polar vortex could be a sign of further developments this winter: It is quite possible that a weak early winter event will be followed by a stronger one in the middle of winter. “The stratosphere always has surprises in store for us,” said Domeisen.

The experts at Severe Weather Europe also believe such a development is possible. It says that long-term data suggests an even stronger disruption in the middle of winter 2026/27.

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A disrupted polar vortex can have consequences that extend beyond winter. Disturbances in February can bring strong and long periods of cold air into spring. In 2013, Germany experienced such a March winter; it was one of the coldest in a long time. Spring was also icy for a long time in 2018: in both cases, it was preceded by a strong disruption of the polar vortex.

This text first appeared in the Tagesspiegel.