Oceanographers say overlapping influences will continue raising ocean heights off California this winter.

Anticipation is mounting in California as the El Niño winter looms.

El Niño now officially ranks as “very strong,” the most extreme category, according to an outlook the National Oceanic and Atmospheric Administration’s Climate Prediction Center published Thursday. The memo gives an 83% chance that El Niño will become “historic” by 2027, surpassing the strength of all events since 1950. 

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As forecasters gain confidence in the extraordinary power of this year’s El Niño, early signs like hurricane swells are already impacting California.  

“It’s El Niño macho, as I call it,” Josh Willis, a senior research scientist for NASA’s Jet Propulsion Laboratory, told SFGATE. “This is a big event, it’s still growing in size, and its impact is just starting to reach out of the tropics.”

El Niño is the warm phase of a natural pattern that emerges in the central and eastern tropical Pacific. During El Niño conditions, weak winds are associated with above-average ocean surface temperatures. Year to year, this seasonal phenomenon alternates with an opposite phase, La Niña, and with neutral conditions.  

This is a Sept. 28, 2026, image from the Sentinel-6 Michael Freilich satellite, which uses radar altimetry to collect sea surface height data. 

The spike in the Pacific’s heat during El Niño years can drive winter weather in California and across........

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