The UK could see temperatures plummet as a potentially record-breaking weakening of the polar vortex raises the chances of wintry weather, including snow.
The polar vortex is a ring of powerful winds that helps keep freezing air near the North Pole. Forecasters warn that a weakening of this system threatens to bring Arctic air to the UK.
Weather experts say such an event happening this early in November is unprecedented, and potentially the earliest ever recorded.
Stratospheric warming under way
Met Office forecaster Marco Petagna said: “At the moment, we’ve got a warming taking place in the stratosphere. The polar vortex in the stratosphere is starting to weaken.”
He added that if winds reverse direction, it would become one of the earliest ever recorded “major sudden stratospheric warming” events.
This, in turn, would allow colder Arctic air to sweep south towards Britain and increase the risk of wintry weather, including snow.
Impact on UK weather
Mr Petagna said: “For the UK, it does increase the chance of cold weather, normally a few weeks down the line, so sort of deeper into November is when we’re more likely to see an influence if it does happen.
“It’s important to emphasise that there was a major warming event last November, and on that occasion it didn’t directly lead to much cold weather in the UK. It doesn’t always happen, it just increases the chance of it occurring.”
Current Met Office forecasts suggest that wintry showers could be seen over higher ground in Scotland on Thursday (November 12) and Friday (November 13).
The Met Office long-range forecast, which runs from Thursday to November 21, also forecasts colder weather and "likely" wintry showers.
Forecast details
The forecast states: "At the start of this period, outbreaks of rain across the south of the UK will clear away as clearer conditions spread from the north.
"A few wintry showers are likely in the far north, but otherwise this will mean a spell of fine and dry weather developing for most areas at the end of next week and the weekend.
"Over the following week, a change to more changeable weather is likely, with Atlantic frontal systems bringing rain and some strong winds. After a cold start, temperatures will probably be above average overall."
