El Niño-driven Kelvin wave raises West Coast sea levels to October records
The gist
A Kelvin wave tied to this year's El Niño pushed San Francisco water levels to 1.73 feet above predictions, breaking the October record.
Scientists say more waves are coming and king tides could compound the elevated water.
How it unfolded
- Jan 2026A swell of warm water called a Kelvin wave was spotted near Micronesia in the western Pacific in satellite imagery.
- Early Apr 2026Kelvin waves reached the eastern Pacific and sea surface temperatures began to warm, raising local sea levels in some areas by as much as 1 to 1.3 feet (30 to 40 centimeters).
- Oct 15, 2026An underwater wave linked to this year's powerful El Niño reached San Francisco Bay, according to ocean researchers and the National Weather Service.