Polar vortex weakens earliest on record: will the UK actually get snow?
Talk of a “big freeze” is everywhere after the polar vortex high above the Arctic suddenly weakened — the earliest event of its kind on record. But forecasters say a snowy Britain is far from guaranteed.
What is happening up there?
Each autumn, strong westerly winds form 10 to 30 miles above the North Pole, keeping the coldest air locked in place. This circulation is called the polar vortex. In recent days it has weakened sharply, stretched, and briefly split into two smaller swirls, BBC Weather reported.
This happens through a process called sudden stratospheric warming (SSW). If the winds go on to reverse, as some forecasts suggest could happen by mid-November, it would count as a major SSW event.
Jeff Knight, lead climate scientist at the Met Office, told the BBC it “would appear to be the earliest on record looking back over the 75 years we’ve been observing”. Until now, the earliest major SSW events happened on 28 November, in 1969 and 2025.
Scientists are not sure why it has come so early. One possibility is the current record-strength El Niño, which Knight said could have “helped load the dice” — though he cautioned there is not enough evidence to be sure.
So will it snow?
Disruptions like this can shift the jet stream and make it more likely that cold northerly or easterly winds bring Arctic air to Britain, sometimes with snow in the east. In past winters, they have been followed by cold spells in Europe and North America.
But timing matters. The Arctic is not yet as cold as it will be in midwinter, so any effect may be weaker. Professor Andrew Charlton-Perez of the University of Reading said that because there has never been an SSW quite like this one, “it is harder to anticipate a cold spell at the moment”.
The Met Office has said the change could raise the chance of colder weather but is not forecasting widespread snow or a major freeze. Its outlook suggests colder conditions may spread from the north towards the end of next week, with possible brief wintry showers in northern parts of the UK while the south stays drier.
The bigger worry: dry weather
For some experts, the real concern is rain — or the lack of it. Most of England and Wales is still in drought, and reservoirs need a wet winter to recover. A typical SSW pattern brings drier conditions, and Charlton-Perez said that would be the “concerning thing”.
Headlines about the polar vortex, including in the Daily Mail, have fuelled hopes and fears of snow. For now, though, forecasters stress it is too early to know how much this unusual event will change the UK’s winter.
