The polar vortex determines how winter will be in Germany. At the beginning of autumn – so now – this is already picking up speed. Is it already foreseeable how much snow there will be?
With a look out of the window it is hard to believe that the weather is improving again this year. But according to the German Weather Service (DWD) there should actually be a sunny and mostly dry late summer * in Germany. While the uncomfortable autumn weather is being scared away again, the course for winter 2021/2022 is currently being set over the North Pole. The polar vortex is already picking up speed. echo24.de * explains what that means for this winter.
Winter 2021: Polar vortex is picking up speed – what that means for the weather in Germany
How frosty or mild a winter becomes depends on the polar vortex. But what actually is a polar vortex? The polar vortex forms at the beginning of autumn – right now at this time when the days here are getting shorter and the sun barely reaches the North Pole. There are two polar vortices on Earth: one over the Arctic and one over the Antarctic. Polar vortices are huge high altitudes with a diameter of around 1,000 kilometers. The temperature of the eddy high up can sometimes be as low as minus 80 degrees.
The polar vortex over the North Pole is relevant for the course of winter in Germany. The eddies are differently pronounced every year. If the polar vortex is unstable, a polar vortex split can occur, which then causes arctic cold in Germany. If there is a lot of precipitation, there is a lot of snow – just like last year in the Black Forest. In the winter of 2020/2021 *, the polar vortex broke in November and divided.
But back to winter 2021/2022: How strong the polar vortex will develop this year cannot yet be said at this point in time. Also not whether there will be a polar vortex split. Incidentally, this is not so rare – as the weather expert Paul Heger explained on the weather portal wetter.com last year, polar vortex splits occur “on average about every two years”. “But with great variability that can hardly be estimated. There were only two polar vortex splits in the 1990s. In the 2000s there were nine, ”explains the meteorologist.
Polar vortex 2021/2021: How will the weather be this winter in Germany?
An initial forecast for winter 2021/22 * is already available from the American weather model NOAA – and at first glance it is not particularly promising for all winter and snow fans. Because according to the NOAA model, the winter in Germany should be on average warm. But: According to the wetter.net meteorologist Dominik Jung, the winter forecasts of the long-term models in recent years have been significantly above the climate mean – that is, they were too warm.
For the first time in a long time, the experts are predicting an average warm winter – which many Germans might find too cold. “A normal average winter would probably be too cool a winter for most of us,” explains Dominik Jung in his analysis of the NOAA winter forecast. On the other hand, NASA’s forecast puts a damper – according to it, this winter, as in previous years, will also be too warm.
So far, the prognoses are not really clear or certain. A clear trend for the winter of 2021/2022 has not yet emerged and the weather models are sometimes divided. There should be more reliable forecasts as soon as the polar vortex over the North Pole has finished forming. * echo24.de is an offer from IPPEN.MEDIA.
List of rubric lists: © Marcel Kusch / dpa