Could the earliest weakening of the polar vortex on record bring UK snow?

The polar vortex above the Arctic has weakened and shifted unusually early in the season, with forecasts suggesting its winds could reverse by mid-November. Such disruption can affect the jet stream and raise the chance of colder weather in Europe, including the UK, but it does not mean snow is certain.

A reversal would qualify as a major sudden stratospheric warming event, apparently the earliest in about 75 years of observations; the previous earliest recorded events were on 28 November, in 1969 and 2025. Scientists say the cause is unclear, though the current strong El Niño may have contributed. Because the Arctic is still relatively warm and this event has few historical parallels, its effects on UK winter weather are difficult to predict.