The Pacific Northwest could be in for a warmer, wetter winter this year, partly driven by a phenomenon called “super El Niño.”
“It is really shaping up right now to be off the charts,” said Larry O’Neill, Oregon’s state climatologist.
The National Oceanic and Atmospheric Administration says there’s a 90% chance of “a very strong event” this fall and winter.
Heavy winter rains could increase landslide risks, particularly west of the Cascades. Another season with low snowpack could set the stage for drought in 2027. Streams and rivers could run warm, making it harder for salmon to migrate and spawn. And coastal fisheries could struggle to catch enough Dungeness crabs to make ends meet.
FILE — Reflected in a pool of melting ice, dirt and grass show through the low snowpack at Mt. Hood Meadows on the resort’s second-to-last weekend in Mt. Hood, Ore., on April 4, 2026.
Eli Imadali / OPB
It’s hard to say exactly what could happen over the next few months, though, since scientists are still learning how this recurring weather phenomenon reacts with climate change.
“We’re kind of in uncharted territory about exactly what kind of impacts we could get with this,” O’Neill said.
El Niño occurs when water along the equator in the Pacific Ocean becomes much warmer than usual. Its counterpart, when the ocean becomes much cooler, is known as La Niña.
In the past, typical El Niño conditions pushed storms southward, leaving the Pacific Northwest drier than usual. But more extreme ocean warming could actually funnel jet streams toward Oregon and Washington.
The region has experienced three super El Niños since the 1980s. During that time, the increased precipitation fell as snow, creating above-average snowpacks.
That’s likely not going to happen this year, O’Neill said, since the world is much warmer than in years past because of climate change.
Although the region is expected to get a lot of precipitation, most of it will fall as rain instead of snow because of warmer temperatures.
“Exactly how it plays out has yet to be determined,” he said. “But, we don’t want people caught off guard with potential for either flooding or a lot more rain than they were expecting.”
Much of Oregon is already built to withstand heavy rain. Even so, wildfires spread across millions of acres this summer, burning through trees and shrubs that keep soils intact. Heavy bouts of rain could loosen that soil and trigger landslides.
“Experiencing something of this magnitude could test our resiliency towards an extreme event,” O’Neill said.
The good news, he added, is that this year’s snowpack is unlikely to be as bad as last year’s.
“Last winter we had our worst snowpack in state’s recorded history,” O’Neill said. “It won’t take much for us to have a better snow season than we did last year.”
Last winter’s snow drought made for a dry spring. When there’s drought, rivers and streams run low and warm, making it difficult for cold-water fish like salmon to migrate and spawn. According to NOAA, warm ocean temperatures can also harm coastal seabirds like common murres.
Warm coastal waters could be bad news for Oregon’s Dungeness crab industry.
In 2015 and 2016, strong El Niño conditions interacted with another marine heatwave that scientists called “the blob.” The high ocean temperatures depleted oxygen levels and increased algal blooms, killing swaths of crabs.
Something similar could happen this year.
“That event was extremely disruptive in terms of the economy and the social structure of the marine communities,” O’Neill said. “If we were to use that as a guide, that would be the base case for what could happen this year.”
