El Niño nearing historic strength
SEA surface temperature differences from normal show abnormally warm waters over the eastern and central tropical Pacific Ocean, indicating strong El Niño conditions.
The climate pattern El Niño that 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 show.
Growing water-temperature anomalies and strengthening abnormal wind patterns over the central and eastern equatorial Pacific Ocean suggest 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.
That includes ongoing heat waves, 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 it is more likely than not that El Niño conditions dissipate by June, returning the Pacific to what are called neutral conditions — the absence of El Niño and its foil, La Niña — according to analysis published Thursday by the National Oceanic and Atmospheric Administration’s Climate Prediction Center.
Powerful storm to lash East Coast with wind-swept rain this
weekend
What happens next is 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 in the fall after five of the past six strong El Niños.
A strong El Niño with uncertain
effects
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 heat continues 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 forecasts a 54 percent chance that this becomes a historically strong El Niño.
“An event of this strength would potentially be in the top 5 of El Niño events since 1950,” the centre’s forecasters wrote — meaning it would be in the same class as El Niño events in 2015-2016, 1997-1998, 1982-1983 and 1972-1973.
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 recordhigh annual average temperatures in 2016. A record-warm 2023 is already certain to break that record, and some climate scientists are suggesting 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 toward 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. A transition away from El Niño —
but to what?
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 percent chance that El Niño will fade away between April and June.
By late summer, the chances of neutral conditions and of a budding La Niña appear about even, according to NOAA, with both estimated at between 40 percent and 50 percent.
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 U.S. winters and wet conditions in Southeast Asia, Indonesia and Australia.
But a resurgence of El Niño also is possible next fall, Kruczkiewicz said. There is historical precedent for all outcomes.
Regardless of whether this El Niño has peaked or will peak soon, it will continue to affect global weather patterns for months to come, DeWitt said.
The Pacific will remain unusually warm at least through the winter.
“You can’t get rid of that much heat really fast,” he said. “It’s going to hang on for several months.”
If La Niña returns by the fall, it would tilt the odds toward another active Atlantic hurricane season. — Washington Post