Nature
PUBLISHED
It’s been said that humanity is in uncharted territory as a “super El Niño” stronger than any on record unfolds in the Pacific. It’s set to have a profound impact on the planet, increasing temperatures globally with a rise in heatwaves, droughts, and wildfires.
Now, there are concerns over a kind of wave it may have unleashed in the ocean. One that’s headed for California.
Oceanic Kelvin waves are not a physical wave of water but a kind of pulse that can transport subsurface heat. Weather forecasters keep an eye on them because they can influence sea levels across vast distances, contributing to the damage caused by storms.
This is part of the reason why concerns are mounting in California. With the Kelvin wave expected to reach the region by fall, it could see the sea level rise by several inches.
This increase isn’t because there’s more water. The water just expands because it is warmer.
It doesn’t sound like much until you factor in the other expected changes under a super El Niño in this part of the world. High tides, big waves, and coastal storms combined with a higher-than-average sea level could contribute to floods and erosion.
And that’s on top of the baseline sea level rise we’ve seen in response to climate change.
Oceanic Kelvin waves aren’t thought to contribute directly to a region’s risk of hurricanes, but there’s another Kelvin wave for that. They’re known as atmospheric Kelvin waves, and they move through the air. According to AccuWeather, they can make the conditions more favorable for thunderstorms and even tropical cyclones to form.
California’s Governor Newsom proclaimed a state of emergency on September 1, 2026, in anticipation of the oncoming conditions the super El Niño will bring. This is in light of reviews by the National Weather Service Climate Prediction Center that concluded at least some parts of California are likely to experience stronger storms in the coming months.
Given California has already experienced severe and destructive storms in recent years, including atmospheric river events, it paints a worrying picture that things could be set to get even worse. As such, it’s hoped these early measures will safeguard people, infrastructure, and natural resources before the storms arrive.
“California is already taking steps now to protect communities from a potentially historic El Niño because we know how serious these weather extremes driven by climate change can be,” said California Natural Resources Secretary Wade Crowfoot in a statement.
“Through the Governor’s state of emergency, we’re cutting red tape and fast‑tracking the flood‑protection and broader preparedness work communities need now.”
