Another warming of the Arctic stratosphere is now underway, with the polar vortex forecast to undergo a final split in March 2026. The zonal mean wind reversal around 60°N and 10 hPa is expected between February 28 and March 1, with its impacts propagating into the troposphere, likely shifting weather patterns over Europe and North America.
A strong stratospheric warming event is underway over the Arctic in early February 2026, rapidly weakening the Northern Hemisphere polar vortex. Forecasts indicate stratospheric westerly wind reversal and vortex split around mid-February, with cores separating further later.
A Sudden Stratospheric Warming (SSW) event evolving over the Arctic through mid-January 2026 is forecast to weaken and displace the Polar Vortex, according to ECMWF and NOAA extended-range guidance. The disturbance is expected to propagate downward over the following weeks, raising the probability of Arctic air outbreaks and colder-than-normal conditions in parts of North America and Europe during the second half of January 2026.
