The Met Office has clarified how the UK might be affected by El Niño amid concerns over a possible 'polar vortex' later this year. It follows warnings from experts that the developing phenomenon is expected to be "unprecedented."
What is El Niño?
El Niño is a naturally occurring climate phenomenon that takes place when sea-surface temperatures across the central and eastern equatorial Pacific become significantly warmer than average. These temperature changes affect atmospheric circulation patterns and can influence weather around the globe.
Although it originates in the Pacific, the impacts of El Niño are felt far beyond that region, with the ability to influence rainfall, temperature and storm tracks across many parts of the world, which can in turn affect everything from agriculture and water resources to ecosystems and energy demand.
Met Office response to headlines
Earlier this year, Professor Adam Scaife, Head of Long Range Prediction at the Met Office, called it an "unprecedented event." He said: "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.
In an article clearing up recent news headlines, the Met Office confirmed that El Niño can increase the likelihood of wetter, stormier and generally milder conditions in the UK during late autumn and early winter. Later in winter, following the peak of El Niño, the stratospheric polar vortex can become weaker. The Met Office says: "This may raise the chance of Sudden Stratospheric Warming events, which can increase the potential for cold weather."
However, the UK weather agency added that El Niño does not determine individual weather events, and the current forecast does not support recent headlines suggesting that the UK is set to be hit with widespread snow associated with changes to the polar vortex.
Forecast for the coming days
Addressing headlines suggesting widespread heavy rain due to El Niño, the Met Office said that the forecast does show bands of rain crossing the UK, followed by showers. The wettest conditions are most likely in the northwest, while the southeast could receive relatively little rain during the period from Saturday, October 10, to Monday, October 12.
Strong winds are also possible, especially in the north, where there is a chance of gales. However, the outlook describes changeable weather with rain, showers and a likely interval of drier conditions, rather than the whole UK disappearing beneath an unbroken wall of rain and snow.
Looking further ahead, occasional rain or showers are most likely in western and north-western areas, interspersed with drier periods. More unsettled conditions may develop towards the end of October or early November, but confidence in specific patterns remains low.
The Met Office said: "The overall message is therefore one of changeable autumn weather: spells of rain, brisk winds, showers and some chilly intervals, but also drier periods. Dramatic nationwide snow and prolonged freezing conditions are not the central themes of the current forecast."
