The Met Office has warned that an intense El Nino event is expected, bringing significant storms and rainfall to the UK in the coming months, with 2027 forecast to be the hottest year on record globally.
El Nino is a naturally occurring weather pattern that happens about every two to seven years and lasts for around a year. It occurs when sea temperatures in the tropical eastern Pacific rise by 0.5C above the long-term average. The powerful natural climate phenomenon pushes up global temperatures and can increase the risks of extreme weather.
Unprecedented El Nino event
The El Nino event developing over the Pacific Ocean is likely to be the strongest in living memory, the Met Office has warned. Added to the effects of human-induced climate change, the Met Office is warning it is "very likely" to mean 2027 is the hottest year on record globally.
Prof Adam Scaife, head of long-range forecasting at the UK Met Office, warned: "We should be clear that this is an unprecedented event. We have never seen an El Nino signal this intense in our forecasts."
The natural warming of sea temperatures is forecast to reach more than 3C in the coming months, making this year's weather event "the largest since the 19th century", according to the Met Office. It means north-western Europe, including the UK, is likely to experience wetter and stormier conditions than normal this autumn and winter.
Global impacts and temperature rise
El Nino also creates a heightened risk of drought in the tropics, southern Africa and north-east Australia. The event also drives an increase in global average temperature, with 2027 forecast to be the warmest year on record.
Prof Scaife said: "A typical El Nino leads to an equatorial Pacific sea-surface temperature rise of between one to 2C, with 2C being a really big event. This implies that if the forecast is accurate - and other forecast systems show similar extreme values - then 2026 will far exceed our recent experience of El Nino and its worldwide climate influences."
Dr Nick Dunstone, Met Office science fellow, added: "During large El Nino events significantly more heat is released from the ocean to the atmosphere leading to an increase in global average temperature, particularly in the calendar year following the winter peak of the El Nino. Hence, 2027 is very likely to replace 2024 as the warmest year on record and be another year to temporarily exceed plus 1.5C above the pre-industrial period."
Recent rainfall and flash flood fears
Parts of the country were hit by heavier showers on Wednesday and Thursday, with the North West seeing the wettest conditions in the last 24 hours. There was 52.5mm of rain which fell over the seaside town of Morecambe in Lancashire, according to the Environment Agency.
This represents a third of the region's rainfall totals recorded over the period between June 1 and August 18 this year, which reached up to 156mm on average, the Met Office said. The sudden heavy rainfall this week also sparked fears of flash flooding as the water has been hitting parched, dry, hard ground.
Professor Stephen Belcher, the Met Office's chief of science and technology, added: "This summer we have experienced heat waves across Europe reminding us of the effects of climate change, this large El Nino is a reminder that natural variations in the climate system are also at play, adding to the stresses of climate change."
There is no clear evidence that climate change is making El Nino events worse, but its weather impacts are more extreme in a warming world.
