An Incoming ‘Super El Niño’ May Bring California a Wet, Hot Winter

Scientists predict that an upcoming “Super El Niño” will make 2026 to 2027 the hottest years on record and bring significant sea level rise to the Bay.

An update on Thursday from the National Weather Service’s Climate Prediction Center said that El Niño is likely to emerge as soon as May and persist through the end of winter.

While El Niño, a warming of the ocean, and La Niña, a cooling of the ocean, are natural patterns that come and go every 2 to 7 years, this year’s El Niño could be one of the strongest on record — and may give Bay Area residents a preview of what life on the coast will be like in just a decade or two if global warming continues at its current pace.

Daniel Swain, a climate scientist with UC Agriculture and Natural Resources, said the term “Super El Niño” is just a colloquial way to describe a “more extreme than merely strong” climate pattern.

“Super El Niño is not something magical, it’s not something new, that’s never happened before,” Swain said this week during his live-streamed “office-hours” series.

Swain said El Niños in 1982, 1997, and 2015 each resulted in “very different global effects” — ranging from record rainfall, which caused some Peruvian rivers to carry 1,000 times their normal flow in 1983, to severe drought in Ethiopia in 2015.

This year’s “Super El Niño,” Swain said, will result in a temporary sea level rise of around 6 inches in California.

“You have to add that number to climate change-caused sea level rise, which — depending on where you are in California — ranges from about 6 inches to a foot over the past century,” Swain said.

Beyond sustained sea level rise, scientists expect major storms and flooding starting this winter. They predict that these storms will be particularly strong as the effects of El Niño compound with the effects of climate change.

Bay Area residents should expect “significant implications for coastal flooding [and] for wind and surf damage along the coast,” Swain said, pointing to the large wave events in Santa Cruz and the king tide flooding in Marin last year as examples of what may be in store.

On KQED’s Forum on Thursday, science writer David Wallace-Wells and climate activist Bill McKibben compared this El Niño to a particularly deadly event in 1877. The main difference between then and now?

“People in the 1870s had no idea what was happening to them, whereas in this case, scientists from across the planet have given us timely warning that we should be using to prepare for what’s ahead,” McKibben said.

This preparedness, however, will likely be impacted by federal cuts to science and weather programs, he warned: “We’re not doing a great job of heeding the wonderful warning that science has been able to provide us. We’re not doing a great job of heeding the wonderful warning that science has been able to provide us.”

San Francisco’s Department of Emergency Management said that the possibility of a strong El Niño is part of the city’s preparedness planning. In the coastal city, El Niño can mean a higher potential for heavy rain, localized flooding, and storm-related disruptions.

“Our focus is on coordinating closely with partner agencies, preparing our response systems, and encouraging the public to take preparedness steps before severe weather arrives,” a spokesperson said in a statement on Thursday.

McKibben reminded listeners that winter is coming: “Don’t let your insurance lapse this year,” he said. “We’re headed into a very, very interesting season, I’m afraid.”