Coastal Flood Warning for San Diego and Orange Counties Starts Sunday as King Tides Return to a Battered California Coast

The National Weather Service has issued a coastal flood warning for San Diego and Orange counties that takes effect Sunday morning, Oct. 25, and runs through Thursday afternoon, Oct. 29. Forecasters expect "significant coastal flooding" that will inundate low-lying homes, businesses and critical infrastructure.

The agency also expects significant-to-moderate beach erosion in Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties, with "isolated damage of structures due to sea water inundation" possible. A coastal flood advisory covers those four counties for the same stretch.

In the San Francisco Bay and Monterey Bay areas, an advisory takes effect today, Oct. 24, and also runs through Thursday. Forecasters warned of up to 1.9 feet of water above ground level near shorelines and tidal waterways.

Records possible in the south

The weather service said tides could break modern-day records in San Diego and Orange counties in the coming days. Adjusted for how warm the ocean is, tides could reach 7.5 to 8 feet or higher above baseline. Baseline is the average low-water level measured between 1983 and 2001. Warm water expands, which raises sea level.

The forecast follows a rough stretch. On a recent Friday, the high tide in San Diego and La Jolla ran 17 inches above the official prediction, according to NOAA forecasts. Santa Monica ran 16 inches over and San Francisco 14. Official predictions don't account for hotter-than-normal water or swells from tropical storms.

In Newport Beach, a swell double the size initially forecast went through 20-foot berms at the Wedge and washed out roads from about 21st Street to 6th Street, city officials said. Councilman Joe Stapleton called it "the worst I've seen it in my 20 years on the Peninsula." Utilities Director Mark Vukojevic said that morning's tide came in 20 inches higher than predicted.

Homes already lost

The damage is not hypothetical. At 3:30 a.m. on Oct. 9 in Long Beach, the boardwalk and 25-foot-wide beach in front of Shawn Curtis's two-story apartment building disappeared. The building tilted toward the ocean. "We rushed for our lives, but it was clear the house was toast," he told NBC News.

More than a dozen homes along the Long Beach shore have been lost. A portion of Pacific Coast Highway in Laguna Beach remains closed as sections crack and slide toward the water. NBC reported that the surge hit on a sunny, calm weekend with no rain or wind beforehand.

Farther south, the rail line through San Clemente, which carries about $1 billion in freight a year and is the nation's second-busiest passenger line, was closed repeatedly in early September when waves and high tides overtopped the tracks, according to a spokesperson for the Orange County Transportation Authority.

Newport Beach braces

Newport Beach declared a local emergency on Monday night, Oct. 19, and activated its Emergency Operations Center. The city expects exceptionally high tides Monday through Wednesday, Oct. 26 to 28. It called them the first in a series of king tide events expected to continue into the new year.

The city council also approved a contract for the West Newport Beach Sand Replenishment Project. It would place about 100,000 cubic yards of sand from the Santa Ana River on eroded beach between 36th and 62nd Streets, with work expected to begin next week. The city is reinforcing beach berms and staging sandbags in flood-prone spots, and it is handing out free prefilled sandbags.

Resident Gary Winthrop said the flooding earlier this month was "honestly life-threatening." He credited neighbors and quick access to sandbags for keeping water out of his house.

Why this season is stacking up

The LA Times lists three overlapping drivers: El Niño, a marine heat wave that has lingered for months, and an alignment of the Earth, sun and moon seen once every two decades. Scripps Institution of Oceanography data show 53 days of record daily water temperatures at Scripps Pier this year, in 110 years of records. Santa Barbara has logged 71 record days in 70 years of records.

NOAA announced in early October an 83% chance that a strong-to-very-strong El Niño will arrive January through March 2027. UC Agriculture and Natural Resources climate scientist Daniel Swain said, "It's likely to get worse before it gets better." Tides are forecast to run higher around Thanksgiving, Christmas and Martin Luther King Jr. Day, and the coast faces the worst if those tides coincide with strong winter storms.

USGS oceanographer Sean Vitousek said, "We're in for a run of pretty exceptional erosion events if this Super El Niño develops as it's expected to."

The climate argument

Some officials tie the damage directly to long-term sea level rise. Laguna Beach Mayor Pro Tem Hallie Jones said, "We've been anticipating rising sea levels 50 years from now. This summer proved that sea level rise is already here." Long Beach officials have said their old infrastructure wasn't built for rapidly changing climate patterns.

President Trump has called climate change a "hoax," "con job" and "scam," according to the Guardian. The immediate drivers named by forecasters and scientists are more specific. Scripps climate scientist Alexander Gershunov called El Niño itself a natural pattern occurring in a warming world, and the sun-Earth-moon alignment is a recurring astronomical event.

The water itself is not in dispute. UCLA Coastal Flood Lab researcher Timu Gallien said of the October damage: "This is just a little bit of a taste of what we will see in the future."

The next test arrives Monday, Oct. 26, when Newport Beach's berms face the first of the predicted tides. The sand replenishment project is scheduled to start the same week, before the Thanksgiving tides.