Does the polar vortex cause an extreme winter in Germany? An expert explains what is behind the gloomy forecasts.
Offenbach – Many will remember: The winter * – more precisely December – in 2010 brought enormous amounts of snow * and icy cold to Germany. If you believe some forecasts for the weather * in winter 2021/2022, it could even exceed the extreme conditions of a good eleven years ago. An expert has now commented on which predictions have the most informative value.
In December 2010 the weather was particularly tough. According to the data from the Wetter.de portal, the average temperature at that time was -3.5 degrees Celsius, more than 4 degrees below the long-term climate mean. Germany experienced the coldest December since 1969. “There has not been an all-German white Christmas since then,” says Dominik Jung * from the Q.met weather service. But should the coming winter 2021/2022 be even colder? The expert explains what the predictions * are all about.
Icy winter forecast for Germany – weather expert: “That makes no sense”
As the graduate meteorologist explains, the coming December in Germany will be “half a degree too warm” according to the current weather model of the US weather service NOAA – measured by the mean climate over the past 30 years in Germany. The expected differences in temperatures could therefore be even higher in January and February 2022.
According to Jung, weather comparable to December 2010 is currently not to be expected for the coming winter. However, if you look at the daily forecasts of the US weather service for December, you can see days with freezing cold. For example, the NOAA forecast for Christmas Eve 2021 in Germany last predicted icy cold. “A real cold tongue from Eastern Europe would come rushing to us in Germany,” explains Jung in a video. Even the “Russian cold whip” is possible. But there is a catch.
“You can show that, but it’s actually dubious,” says Dominik Jung. This is because it is an “experimental model”. The up-to-date forecasts made early on would accordingly have little informative value. “The calculations usually change every six hours,” says Jung. “That doesn’t make sense.” The monthly forecast for Germany simply takes into account the data from various calculations for the weather. “That is of course more meaningful than just relying on individual runs all the time,” says Dominik Jung.
Weather in Germany: Can we expect freezing cold and snow in winter?
In any case, it is difficult to forecast the weather in winter at such an early stage. How frosty or snowy the winter in Germany will ultimately be depends largely on the polar vortex, which only forms at the beginning of autumn. Polar vortices are gigantic high altitude lows that can reach a diameter of several thousand kilometers above the Arctic and the Antarctic.
The arctic low altitude above the North Pole is primarily responsible for the winter weather in Germany. According to wetter.de, the polar vortex is stable “when the temperature differences between the equator and the pole are particularly large.” The result of an intact polar vortex: warm and wet westerly winds. As a result, winter on the mountains is often cold and snowy and in lower elevations it is often wet and rather muddy.
If the polar vortex weakens, it also affects the weather in Germany. Cold air can then break out of the cycle, icy winds from northern and northeastern Europe flow into Germany and bring plenty of snow and frost. A so-called polar vortex split only caused a cold spell in Germany in February 2021.
Weather in Germany: How cold will winter 2021/2022 be?
Even if the currently most reliable forecast for winter 2021/2022 in Germany is a little too warm, according to Dominik Jung it does not have to mean that winter lovers will not get their money’s worth. Because: “A normal average winter would probably be too cool a winter for most of us,” Jung explains his analysis of the NOAA winter forecast to the weather portal wetter.net. After all, the long-term models of recent years have always been significantly above the climate mean.
Weather news *: All information about forecasts on our topic page.
The experts can make more precise statements about the weather in the winter months as soon as the polar vortex has completely formed. In principle, one thing is clear: the fact that temperatures all over the world are rising steadily as a result of climate change, however, is increasingly weakening the polar vortices over the Arctic and Antarctic.
According to Wetter.de, this means that winter will also be warmer and warmer in the future. However: Extreme weather phenomena are becoming more and more likely, not just in winter. (yw) * op-online.de is an offer from IPPEN.MEDIA.
List of rubric lists: © B. Leitner / Imago
