A record early sudden stratospheric warming could disrupt the polar vortex, potentially bringing colder weather to Europe as early as November 2026.
Early SSW could disrupt polar vortex
A sudden stratospheric warming (SSW) could disrupt the polar vortex and bring colder temperatures to Europe as early as November 2026, according to recent reports. However, the actual impact on France remains uncertain, with forecasters emphasizing the complexity of the phenomenon.Polar vortex and its stratospheric role
The polar vortex is a low-pressure zone at altitude centered on the geographic poles, existing in both the troposphere and stratosphere. The stratospheric vortex, which is the focus of current discussions, exists only in winter and can influence weather patterns in Europe if it moves towards the mid-latitudes.SSW and its causes
According to Guillaume Jauseau, a physics-chemistry student and creator of the weather platform RecordPy, models predict a major disturbance to the polar vortex, with its westerly winds potentially weakening or reversing. This reversal is termed a sudden stratospheric warming (SSW). Jauseau explains that SSWs are caused by Rossby waves, which can destabilize the polar vortex.El Niño’s influence
El Niño is also playing a role in this phenomenon, as it generates giant air waves that can destabilize the polar vortex. An El Niño episode is currently underway in the Pacific and is expected to last until February 2027.Uncertain impact on France
Météovillages, a specialized weather account, suggests that this SSW would be the earliest ever recorded, with three weeks of advance on the previous record. However, the impact on France remains uncertain, as an SSW does not necessarily lead to colder temperatures. The cold air must descend from the stratosphere to affect surface temperatures, a scenario that is not guaranteed.Seasonal forecasts for France
Seasonal forecasts from Météo-France suggest a warmer than normal winter for France and Corsica, with a 70% probability. While isolated colder episodes are possible, a cold snap of a few days would be compatible with a generally mild start to winter. Forecasters remain cautious, emphasizing the complexity of the phenomenon and the uncertainty surrounding its effects.
