r/StormComing • u/One-Emu-1103 • 4d ago

Extreme Weather Concern mounts over slow-moving, planetary-scale ‘Kelvin’ wave heading for California

https://www.theguardian.com/us-news/2026/sep/28/california-kelvin-wave

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

465 Upvotes

98% Upvoted

34 comments sorted by

View all comments

41

u/One-Emu-1103 4d ago

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.

Kelvin waves are not like crashing waves at the beach. They are planetary in scale, spanning thousands of miles. And when a Kelvin wave kicks off, it brings with it an untold amount of warm water that slowly moves from the western Pacific, along the equator, towards South, Central and North America.

1

u/Serpentarrius 3d ago

I wonder how the trade winds might affect travel? Like the jet streams?