New El Niño warning issued as polar vortex looms
This autumn and winter, the El Niño weather pattern is associated with an increased risk of deep freezes.
A polar vortex threatens a cold snap this winter, with snow forecast, as The Met Office issues a new warning on El Niño.
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A significant El Niño is expected to occur towards the end of 2026, with forecasts predicting a brutal polar vortex.
The Met Office says El Niño is a naturally-occurring climate phenomenon that develops in the tropical Pacific Ocean.
This autumn and winter, the weather pattern is associated with an increased risk of deep freezes.
Although El Niño is only one of many factors influencing the UK's weather, it may increase the chances of a more unsettled period during the coming months.
Read More: Britain braces for October thunderstorms after series of sweltering nights in 'tropical September'
A Met Office spokesperson said: “Through the latter part of the winter, following a peak in El Niño, the stratospheric Polar Vortex can become weaker, leading to an increased chance of Sudden Stratospheric Warming (SSW) events unfurling, increasing the potential for cold weather.”
SSW warms between 10km and 50km above the Earth's surface. Cold air rushes downwards, "blocking" the jet stream.
Dr Will Lang, chief forecaster at the Met Office, said it was a “subtle shift in the odds” that El Niño would cause havoc in the coming autumn, rather than a total certainty.
He said: “We are going in with a heightened potential for wet weather, heightened potential for potentially stormy conditions, and that leads through to a heightened potential for flooding.”
Professor Adam Scaife, Head of Long Range Prediction at the Met Office, said El Niño will be an "unprecedented event."
“We have been signalling for months that the developing El Niño will be an unprecedented event. The fact that it has already exceeded previous records – with several weeks to go before it peaks later this year – shows the enormity of this El Niño.
"Scientists are still assessing whether the impacts will be in proportion to its magnitude, but we are already seeing expected effects worldwide.”