El Niño is emerging even faster than expected in the Pacific, and U.S. forecasters now say there is a 2 in 3 chance its peak strength will be strong or very strong. The Climate Prediction Center said Thursday that El Niño is expected to climb above the 0.5-degree Celsius threshold by next month, with the odds of a Super El Niño between November and January rising to about 1 in 3.
The agency also said the chances of El Niño lasting through winter have increased to 96%. That marks a sharp shift from last month, when the center favored neutral conditions through June. Michelle L’Heureux said a stronger El Niño is more likely if changes in the atmosphere continue to sync with changes in the tropical Pacific Ocean this summer.
Some computer models go even further and show this year’s potential Super El Niño could be the strongest on record. NOAA records date back to 1950, and the strongest Super El Niño in that archive was the 2015-2016 event. Other strong El Niños listed in the record include 1997-1998, 1982-1983 and 1972-1973.
El Niño is a natural climate cycle that develops when the tropical Pacific Ocean warms enough to alter wind patterns across the atmosphere. It usually appears every two to seven years and lasts nine to 12 months, peaking in the Northern Hemisphere winter. Once temperatures rise more than 0.5 degrees Celsius above average for an extended period, weak El Niño conditions are considered underway. To qualify as very strong, or Super El Niño, waters must be more than 2 degrees above average.
That matters because stronger El Niños are more likely to drive drought, heat waves, flooding rainfall, wildfire danger, water supply problems and disruption to the Atlantic hurricane season. The setup now points to a Pacific that is warming quickly, backed by a vast pool of warm water that has built up in the depths of the central and eastern equatorial Pacific in recent weeks.
The question for forecasters is not whether El Niño is arriving, but how hard it will hit once the atmosphere fully locks in. The center said there is still substantial uncertainty in the peak strength of El Niño, even as the odds shift toward a winter event that could test the upper end of NOAA’s records.
