Biggest El Niño for a century forecast to bring UK more autumn rain and storms
‘Unprecedented’ weather pattern over Pacific Ocean to be felt worldwide, with severe droughts expected in some areas
The El Niño event developing over the Pacific Ocean is likely to be the strongest for more than a century and make 2027 another record-breaking year for heat, the UK’s Met Office has said.
Increased rainfall and storms are forecast to hit the UK this autumn as a result of the “unprecedented” weather pattern, while the pulse in heat it generates means the global temperature will temporarily exceed 1.5C above the preindustrial average, according to the national weather service.
Some scientists have said temperatures could rise by as much as 1.7C during 2027. “We should be clear that this is an unprecedented event,” said Prof Adam Scaife, the Met Office’s head of long-range forecasting. “I have never seen an El Niño signal this intense in our forecasts.”
Scaife said a typical El Niño involved Pacific sea temperatures rising by more than 1C, “with 2C being a really big event”. This year Pacific sea temperatures are expected to rise by 3C, making this El Niño “the largest since the 19th century”, according to the Met Office.
Speaking to BBC Radio 4’s Today programme, Scaife said: “We’re expecting the biggest El Niño for over a century, peaking at something over 3C. That is unheard of in modern climate records … It’s up 2C degrees already.”
He said the effects would be felt worldwide, adding they would be “particularly strong throughout the tropics, where we expect really severe droughts in places like South America and the west Pacific”.
He said: “Then there are wave-like disturbances that come out from the tropics and affect places like the UK. So we already see signals for increased rainfall and storminess in the autumn here in the UK around November time.”
There is also a heightened risk of drought in southern Africa and north-east Australia, while north-western Europe – including the UK – was likely to experience wetter and stormier conditions, the Met Office said.
The Met Office is just the latest forecaster to highlight the magnitude of the current El Niño cycle. The US National Oceanic and Atmospheric Administration last week said there was a “greater than 90% chance of a very strong event”.
“The Met Office predictions are actually some of the most conservative out there,” said Liz Stephens, a professor in climate risks and resilience at the University of Reading.
The UN warned in early August that the conditions created by El Niño could push 50 million people into acute hunger by the end of next year.
Prof Hayley Fowler, the director of the Centre for Climate and Environmental Resilience at Newcastle University, said: “The super El Niño evolving in the Pacific will likely be the biggest ever recorded, reaching or exceeding the levels of the 1877-78 El Niño which caused widespread impacts, including famines and around 50 million deaths – 3-4% of the global population – mostly across Asia and South America.”
El Niño is a cyclical weather phenomenon taking place every two to seven years. Under normal circumstances the Pacific’s trade winds push warm water to Asia, while colder water rises by South America. Under El Niño, the pattern weakens, or goes into reverse and the water in the eastern Pacific heats up, shifting weather patterns all around the equator.
The extent to which rising global temperatures as a result of carbon pollution affect the development of El Niño is unknown. But scientists say the pulse in heat El Niño brings can amplify baseline heating.
Dr Nick Dunstone, a science fellow at the Met Office, said: “During large El Niño 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 Niño.
“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 preindustrial period.”
Bill McGuire, professor emeritus of geophysical and climate hazards at UCL, said: “The addition of much of this heat to the atmosphere will make it extremely likely that next year will be the hottest on record globally, perhaps even reaching – even exceeding – 1.7C above preindustrial times.”
A series of record heatwaves and a lack of rainfall in recent months has brought the driest July in 190 years and has pushed almost three-quarters (71.3%) of England, and all of Wales, into drought, putting severe pressure on the water system, wildlife, farmers, emergency services and infrastructure.
After an emergency meeting to discuss the heatwave last week, Andy Burnham said: “We might be in for a wet autumn and winter straight after this, because of El Niño and some of the issues there, which was reported to Cobra.”
Parts of the country were hit by heavier showers on Wednesday and Thursday. The north-west of England recorded the wettest conditions in the last 24 hours, with 52.5mm of rain falling over the seaside town of Morecambe in Lancashire.
Forecasters and officials have said it could take months of sustained rainfall before rivers, reservoirs and groundwaters are completely replenished, which is when a drought would be officially over.
Seven reservoirs in England were currently classed as having “exceptionally low” storage levels, up from five a week ago, the Environment Agency said on Friday.
Wimbleball and Clatworthy in Somerset, and Clywedog in Powys, which provides water for central and north-west England, are all less than half full; Hanningfield in Essex and Blithfield in Staffordshire are about half full. The Dove reservoir group in Derbyshire and Grafham in Cambridgeshire remain about two-thirds full.
The overall level of reservoir storage in England stands at 63%, down from 66% a week ago and 16 percentage points below the long-term average for the time of year.