A Historic El Niño Takes Shape
Federal forecasters now say the El Niño that has been building in the tropical Pacific is likely to become the strongest on record, with major consequences for winter weather across the United States. In its October update, NOAA’s Climate Prediction Center put the odds at 83% that this event will surpass every El Niño since record-keeping began in 1950. The news came as September closed out the first full month of what meteorologists are already calling a “Super El Niño.”
Water temperatures in the central equatorial Pacific averaged more than 2 degrees Celsius above normal in September — the threshold for “super” status. Over the past week, readings in the eastern Pacific climbed to 2.3 degrees above average, with some pockets running as much as 4 degrees warmer than normal. “Chances remain high for a historic event that would exceed the strength of previous El Niño events dating back to 1950,” the Climate Prediction Center said.
A Developing, Not Yet Official, Record
Because NOAA officially measures El Niño using three-month averages and a newer index that filters out background ocean warming, the event has not yet been certified as a record. But the trajectory is clear: forecast models show the anomaly peaking this winter before weakening next spring. By one older daily measure, current warmth already ranks as the highest ever observed.
What It Means for the US This Winter
El Niño shifts the Pacific jet stream, altering storm tracks and precipitation patterns. For the US, the practical effects divide the country. The West and South are expected to see a more active winter, with above-average rain and mountain snow. California sits squarely in the crosshairs. State climatologist Michael Anderson told The Guardian that El Niño could add roughly a foot of sea-level rise on top of the 8 to 12 inches already caused by climate change over the past century. Landslides, flash floods, debris flows on recent wildfire burn scars, and battering surf are all on the table — and could arrive simultaneously.
“What we’re really looking at is the compounding element,” said Nick Brubaker, chief resilience officer for Marin County’s office of emergency management. Last week, high tides already flooded intersections in Marin County and other coastal communities, an early warning of what December may bring.
In the Pacific Northwest, the picture is different. KPTV meteorologist Mark Nelsen, drawing on 35 years of forecasting experience in northwest Oregon, expects a milder and potentially drier winter than average. Long cold snaps and extended snow are unlikely, though he warns that a single snow or ice storm remains possible, most likely by mid-January. El Niño winters in the region also tend to produce mild Februaries and do not drag into early spring. The storm action, he says, will mostly head south into California.
A Region-by-Region Split
The contrast is typical of strong El Niño years: southern-tier states get wet, while the northern tier often dries out. NOAA’s maps show above-average water temperatures stretching across the central Pacific, the engine driving these shifts. Forecasters caution that El Niño is only one influence — other patterns like the Pacific Decadal Oscillation and broader ocean warming also shape each winter.
Stakes Rise as California Braces for Compounding Disasters
California’s emergency planners are treating the coming months as a test of readiness. The state is still recovering from a devastating 2025 firestorm in Los Angeles and summer burns near Big Sur, leaving steep, bare slopes vulnerable to debris flows. A wet winter could turn those scars into corridors of mud and rock. Coastal communities, meanwhile, face the twin threats of storm surge and rising seas.
Experts describe the risk in stark terms. “Like an earthquake,” one state official said of the potential for a sudden, widespread disaster. The concern is not just one hazard but many at once — floods, landslides, erosion, and marine heat impacts that could devastate fisheries and ecosystems.
For the Pacific Northwest, the stakes are lower but not negligible. A mild winter may ease heating demand and reduce flood risk, yet even a single ice storm can paralyze a region unaccustomed to prolonged freezing. Nelsen urges residents to have a plan, noting that if such a storm occurs, it would likely arrive by mid-January at the latest. As with any strong El Niño, the odds favor warmth overall — but exceptional events can still slip through.
A Changing Baseline
This year’s event is unfolding against a backdrop of record ocean heat and a warming climate. Scientists note that global warming is layering extra sea-level rise and moisture onto natural cycles, potentially amplifying El Niño’s effects. The 2026-2027 winter may thus become a case study in how a familiar climate pattern behaves in an unfamiliar, hotter world. For now, forecasters and emergency managers from Sacramento to Seattle are watching the Pacific, knowing that the strongest El Niño in 75 years will leave its mark — one way or another.
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