El Niño's Dreaded 'Kelvin Wave' Is About to Hit California

Key Points:

• Southern California coastal communities like Malibu, Long Beach, and San Clemente are experiencing significant beach erosion due to rising sea levels, a situation expected to worsen with an upcoming El Niño-driven phenomenon.
• El Niño weakens and reverses equatorial winds, generating oceanic Kelvin waves—large pulses of warm water—that travel across the Pacific and along North America's coast, potentially raising sea levels in southern California by up to one foot by early October.
• Climate change has already warmed Pacific waters, causing marine heatwaves and thermal expansion that elevate baseline sea levels and increase coastal flooding and erosion risks in California.
• Additional factors such as land subsidence from groundwater pumping and global sea level rise from polar ice melt are compounding the coastal hazards faced by California communities.
• Although the Kelvin wave's impact on sea levels is temporary, El Niño events often produce multiple waves, potentially keeping sea levels elevated for months, with some experts predicting normal levels may not return until spring 2027.