Environment
Kelvin-wave pulses raise Southern California erosion concern
Warm-water pulses associated with El Niño are expected to temporarily lift coastal water levels, increasing exposure when high tides, heavy surf or storms arrive.
A series of coastally trapped Kelvin waves is expected to reach California this month and move north along the West Coast, the Associated Press reported October 3. Scientists said the pulses could raise coastal water levels by roughly six inches and in some places as much as a foot, creating a higher starting point for waves, tides and storm surge.
What it means locally
Kelvin waves are broad ocean pulses, not breaking waves or tsunamis. They do not automatically cause flooding, but elevated water levels can amplify beach erosion and coastal flooding when they overlap with king tides, large surf or winter storms. NOAA says the ocean connection is especially influential off Southern California and that the strongest effects of the developing El Niño are expected from fall into winter.
NOAA also expects El Niño-driven warming to extend existing marine stress along the California coast. Residents near vulnerable shoreline areas should use current tide, surf and local emergency forecasts rather than treat the regional projection as a site-specific warning.
Original reporting: Associated Press →
Official scientific context: NOAA Fisheries →