If the winds continue to weaken and end up reversing as forecast, this will be known as a major SSW event.
Jeff Knight, lead climate scientist from the Met Office, told the : “It would appear to be the earliest on record looking back over the 75 years we’ve been observing…with most experts agreeing this is a very unusual event.”
The current earliest major SSW event occurred on 28 November in 1969 and 2025.
Reasons for why we’re seeing such an early event is not clear. It could be just part of the variability of our weather patterns.
But we also know in a “normal” El Niño year, this can typically bring a weakening of the polar vortex towards the end of winter.
While the warmer waters of the Pacific in an El Niño directly disrupt the weather around tropical areas, pulses of energy in the atmosphere, known as planetary waves, can cause disturbances even at polar regions.
These waves can push the polar vortex out of position and break the circulation up.
With the current record El Niño taking us into uncharted territory in terms of disruption to worldwide weather patterns, Knight suggested it could have “helped load the dice for this SSW event. However, because this is so rare, there’s not enough evidence”.
A link between a strong El Niño and early onset of a SSW event is unclear and will need further research.