Polar vortex and record-breaking El Niño: what winter will be like in Europe
An unprecedented weakening of the polar vortex for early November may occur over the Arctic—such an event has not been recorded since 1958, when observations began.
This vortex is a system of winds at an altitude of 15–50 km that typically keeps cold air over the Arctic.
European and American models indicate that at an altitude of around 30 km, temperatures may exceed the norm by more than 27 degrees, and westerly winds could even reverse direction. A split in the vortex occurs approximately six times per decade, but usually in January or February.
At the same time, El Niño is gaining strength in the Pacific Ocean. In October, water temperatures were 3.3 degrees above normal, and by December, the deviation could reach 3.8 degrees—surpassing the record set in 2015/2016.
Meteorologists do not yet know how this combination will affect Europe, as there are no historical precedents. Sudden stratospheric warming can typically be predicted only about ten days in advance.
A sharp cold snap is not expected: effects usually manifest within two to six weeks, and the vortex may recover. November is expected to be warmer than usual. A mild winter is most likely, but periods of cold and snowfall are not ruled out. It is still too early to forecast a snowy Christmas.
