Monday October 5, 2026
AP News —
Sea levels along the West Coast will begin to rise by up to a foot this month as a series of pulses of warm water called Kelvin waves hit the shoreline and move north, sparking concerns about beach erosion and flooding in areas already impacted by climate change and El Niño.
Kelvin waves are not like tsunamis, and they don’t curl over and crash on the beach. A better image is water sloshing in the bathtub or a swimming pool during an earthquake. In the ocean, they are bulges of water that lift the sea level as they move along the coast. They’re common during El Niño events, but this year’s super El Niño could intensify the impacts, experts say.
Over the next week, the 6-inch to foot-tall surge will move north along the California coast at about 6 miles per hour (9.6 kilometers per hour), or 150 miles per day (241 kilometers per day), bringing higher sea levels to Oregon and Washington state. Experts predict the waves will continue to pass through from October until February.