Full Breakdown
Southern California Coast Faces Record Flooding Amid Strong El Niño
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In this breakdown
01
Core Event: Record Tides Flood Pacific Coast Highway Communities
On Tuesday, unusually high tides inundated low-lying streets along Pacific Coast Highway at Sunset Beach, closing the roadway and flooding homes and businesses in Newport Beach, Long Beach and San Diego. The National Weather Service (NWS) extended coastal flood advisories through Friday, noting “seawater over low-lying areas” and water reaching the base of some structures. Caltrans announced a partial closure of the highway for Thursday as tides remained elevated.
02
Background & Context: El Niño, Kelvin Wave, Marine Heat Wave, and Climate Change
Meteorologists attribute the surge to a confluence of factors. A strong El Niño has generated a Kelvin wave that transports warm equatorial Pacific water northward along the coast. A months-old marine heat wave, separate from the El Niño, has further raised sea temperatures. Scientists say the combined warming expands seawater, adding 1.25 to 1.8 feet above levels driven solely by lunar and solar forces. Climate researchers warn that these oceanic anomalies amplify the impact of “king tides,” the annual astronomical high tides that already push water onto the shoreline.
03
Data & Statistics
- San Diego Harbor tide gauge recorded 8.52 feet, surpassing the previous record of 8.26 feet set in July.
- Los Angeles Harbor (San Pedro) reached 8.19 feet, the highest since records began in November 1923.
- Santa Barbara measured 8.04 feet; La Jolla hit 7.98 feet, breaking the 2015 record of 7.83 feet.
- Sea-surface temperature at the Ellen Browning Scripps Memorial Pier in La Jolla hit 73.6 °F—about 9 °F above the long-term average, the warmest on record for that date.
- Climate projections estimate a 0.8-to-1.2 foot sea-level rise by 2050, potentially inundating billions of dollars of coastal property.
04
On-the-Ground Reports
Laguna Beach City Manager Dave Kiff warned that a combination of high tides, a storm, and blocked drainage would create a “worst-case” scenario.
05
Official Statements & Responses
NWS meteorologists Devin Black and Ryan Kittell emphasized the extreme nature of the tides, noting that several gauges posted record levels and that the angle and magnitude of southwesterly swells heightened risk for Orange and San Diego counties.
City officials in Newport Beach deployed large sand berms, tidal valves, and emergency pump trucks to divert water back into harbor channels, but the pumps could not keep pace with inflow. Laguna Beach businesses installed floodgates at storefronts, a measure that works for brief rain events but may be overwhelmed by prolonged king tides. UC Berkeley professor Kristina Hill cautioned that adding a foot of water to the already high levels, combined with a low-pressure system, could be “devastating” for residents who have never experienced such inundation.
06
Why It Matters: Future Winter Flood Risk and Infrastructure Challenges
Scientists project that even higher king tides will occur around Thanksgiving and Christmas. If a strong storm coincides with those tides, flooding could exceed current impacts. The Public Policy Institute of California’s 2024 assessment warns that rising seas and more frequent coastal storms will strain sewage and wastewater infrastructure, many of which sit at low elevations. Hill advocates pilot projects such as floating homes to adapt to the accelerating sea-level rise expected after 2050.