Man walks along a snowy road with a fluffy dog on a leadImage source, PA
BySarah Keith-Lucas, Lead Weather Presenter and Ben Rich, Lead Weather PresenterUpdated 19 minutes ago

The spiralling winds of the polar vortex high above the Arctic have reversed direction marking the earliest 'major sudden stratospheric warming' on record.

These polar winds usually blow in a westerly direction keeping cold air locked high above the North Pole.

However in recent weeks the polar vortex has weakened and shifted position. Observations have now shown a switch to easterly winds, which experts say defines a 'major sudden stratospheric warming' or SSW.