Peaking El Niño could become one of the strongest in 75 years
The El Niño climate pattern, which has pushed the planet to record warmth over the past six months, is nearing its peak, potentially as one of the strongest El Niño events observed over the past 75 years, new data shows.
Growing water temperature anomalies and strengthening abnormal wind patterns over the central and eastern equatorial Pacific Ocean suggest that the extreme weather impacts for which El Niño is known will continue – if not accelerate -– around the world.
What happens in that zone of the Pacific has cascading effects around the globe.
This includes ongoing heatwaves, drought and fires in Australia, deadly floods in Kenya, and drought and floods in parts of South America. In the United States, it is likely to mean more heavy rain along the Gulf Coast and in Florida, which has experienced major recent flooding, and wet and stormy conditions in California, a pattern that has been forecast to set in soon.
At the same time, scientists now see a coming end to the present El Niño.
Climate models suggest that it is more likely than not that El Niño conditions will dissipate by June, returning the Pacific to what are called neutral conditions – the absence of El Niño and its foil, La Niña – according to an analysis by the US National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Centre.
What would happen next was anyone’s guess, said Andrew Kruczkiewicz, a senior researcher at the International Research Institute for Climate and Society at Columbia University.
“How long will we stay in neutral? That’s one of the big questions we’re going to be asking more and more,” he said. “We don’t really have a strong indication either way.”
La Niña conditions have developed during the northern autumn after five of the past six strong El Niños.
El Niño is known for warmer than normal waters along the equator in the eastern and central Pacific, a pattern that drives wet and stormy weather to some parts of the planet while starving others of moisture.
Recent observations in that area show that heat is continuing to build in the ocean surface, influenced by unusual wind patterns blowing in from the west.
The conditions are so pronounced that the climate centre is forecasting a 54% chance that this will become a historically strong El Niño.
“An event of this strength would potentially be in the top five of El Niño events since 1950,” the centre’s forecasters wrote – meaning it would be in the same class as El Niño events in 2015-16, 1997-98, 1982-83 and 1972-73.
Those events are remembered for devastating floods, droughts and wildfires around the world.
The most recent extreme El Niño pushed the planet to what were then record high annual average temperatures in 2016. A record warm 2023 is already certain to break that record, and some climate scientists are suggesting that it could be pushed even higher in 2024.
In which places this El Niño brings more weather extremes, and what kinds, depends on how it interacts with other climatic patterns and fluctuations.
Other phenomena that can dictate dominant local weather patterns include episodes of sudden stratospheric warming, when polar temperatures dramatically rise and frigid air shifts towards lower latitudes, and the Madden-Julian Oscillation, a pattern across the Indian and Pacific oceans that was largely responsible for last winter’s wet and snowy conditions in the American West.
“Each event is a little bit different,” said David DeWitt, the climate centre’s director.
So far, climate models’ predictions have largely been borne out as El Niño has developed, although few, if any, scientists predicted the record-setting warmth that has dominated the planet since July. Now those models predict a 60% chance that El Niño will fade away between April and June.
By the late northern summer, the chances of neutral conditions and of a budding La Niña appear about even, according to NOAA, with both estimated at between 40 and 50%.
La Niña is known for cooler than normal waters across the central and eastern equatorial Pacific, and is associated with intense Atlantic hurricane seasons, mild and dry US winters, and wet conditions in Southeast Asia, Indonesia and Australia.
But a resurgence of El Niño was also possible next autumn, Kruczkiewicz said. There is historical precedent for all outcomes.
Regardless of whether this El Niño had peaked or would peak soon, it would continue to affect global weather patterns for months to come, DeWitt said. The Pacific would remain unusually warm at least through early next year.
“You can’t get rid of that much heat really fast,” he said. “It’s going to hang on for several months.”