California is heading into what forecasters describe as a rare and potentially record setting winter, as a powerful Super El Niño converges with exceptionally high king tides and rising sea levels driven by climate change. Officials are already observing higher than typical tides along the coast, with swells eroding beaches, damaging infrastructure and even exposing long buried coastal structures, all before El Niño has fully intensified.
The setup is drawing comparisons to the historic Super El Niño of 1997 and 1998, when nearly a year’s worth of rain fell on downtown Los Angeles in a single month, triggering deadly landslides and destroying a significant portion of the Santa Monica Pier. That event remains the benchmark many Californians and scientists use when trying to anticipate what a Super El Niño winter could look like, though experts caution that past events don’t always predict future ones with precision.
A rare convergence of three separate threats
What makes this coming winter particularly concerning is the simultaneous overlap of three distinct factors. A Super El Niño, expected to be among the strongest on record, is developing at the same time as an especially high point in an 18 year astronomical high tide cycle, according to researchers at the University of California, Santa Cruz. Layered on top of both is the steady rise in sea levels tied to long term climate change, meaning coastal water levels are starting from an already elevated baseline before El Niño’s effects are even factored in.
Why El Niño raises sea levels in the first place
El Niño increases coastal water levels through two connected mechanisms, both tied to warmer than average ocean temperatures in the tropical Pacific. Warmer water physically expands and takes up more space, contributing directly to higher sea levels. At the same time, large, slow moving ocean waves known as Kelvin waves carry that warm water eastward across the Pacific, and once they reach the coast of South America, they become trapped along the coastline and travel north and south, raising sea levels by roughly six inches to a foot as they move.
Satellite data has already tracked this rising water expanding northward from South and Central America toward California’s Baja Peninsula, with further northward movement expected as the season progresses.
Bigger waves are also part of the equation
Beyond elevated water levels, El Niño years tend to generate significantly stronger wave activity. Research shows Pacific storms typically produce roughly 30 percent more wave energy during an El Niño year compared to a year without the pattern. During particularly intense past events, including the 2015 to 2016 Super El Niño, wave energy increased by as much as 50 percent…