Concern mounts over slow-moving, planetary-scale ‘kelvin’ wave heading for California

The ocean phenomenon could raise sea levels by up to a foot as El Niño keeps warm water trapped along the coast

Concerns are mounting about an ocean phenomenon known as a kelvin wave that could raise sea levels along the California coastline by up to a foot, as scientists say El Niño is supercharging the threat of storm surges and flooding in the coming months.

As an incredibly strong El Niño continues to develop in the Pacific, the phenomenon brings with it a strange shift in the ocean. The kelvin wave phenomenon is created when trade winds that usually blow from South America towards Asia die down or reverse in El Niño years, setting off a massive, slow-moving slosh of water.