NWS Warns of Record Coastal Flooding Across Southern California

Southern California coastal communities are bracing for days of flooding this week as the National Weather Service forecasts what it calls "record-breaking tides," according to The Guardian. The agency says the surge could close roads, flood homes and businesses, and reach critical infrastructure in San Diego and Orange counties through Thursday.

Farther north, from San Luis Obispo County down through Los Angeles County, forecasters expect "minor to moderate" coastal flooding, with tides climbing as high as 8 feet, the Guardian reported.

Which areas face the worst flooding risk?

The National Weather Service office in San Diego has told residents to stay away from the water during peak tide times. "Avoid the beaches during high tides, keep farther back from the ocean than usual (waves will run much farther up the beach that expected), stay off rock walls/jetties, and make sure flood-prone property is protected this week," the office said in a statement cited by the Guardian.

San Diego and Orange counties are expected to see the most serious impacts, with the NWS warning that flooding there could be significant enough to shut down roads and reach buildings and infrastructure beyond the usual flood zone.

How high are the tides getting, and why?

By Monday morning, the NWS office in Los Angeles reported it was already recording record tide levels. Preliminary readings from the agency's San Pedro tide gauge hit 8.02 feet, the highest mark in data going back to November 1923, according to the Guardian.

Forecasters are pointing to two factors pushing water levels above normal: El Niño conditions and a Kelvin wave moving through the Pacific. Newport Beach City Manager Seimone Jurjis said in a statement reported by the Guardian that ocean water levels in the region have already been running 15 to 22 inches higher than expected because of those conditions.

"A foot and a half may not sound like much, but in a coastal community like ours, it can mean the difference between water staying below a seawall and water spilling into streets, garages and homes, especially during some of the highest tides," Jurjis said, according to the Guardian.

What is Newport Beach doing to prepare?

Newport Beach moved early. More than a week before the highest tides were forecast to hit, the Orange County city declared a local emergency, the Guardian reported. City staff have been deployed to inspect infrastructure, reinforce beach berms, and install sandbags and other flood equipment.

The city is also handing out free sandbags and is urging residents to check the areas around their own properties for vulnerabilities before the worst of the tides arrive, according to the statement cited by the Guardian.

What is the timeline for flooding this week?

Based on the National Weather Service forecasts reported by the Guardian, the week is shaping up like this:

• More than a week ago: Newport Beach declared a local emergency and began reinforcing berms and distributing sandbags ahead of the forecast surge.
• Monday: The NWS office in Los Angeles recorded a preliminary tide reading of 8.02 feet at the San Pedro gauge — the highest in records dating to November 1923.
• Monday through Thursday: San Diego and Orange counties face the window for "significant" coastal flooding that could close roads and reach homes, businesses, and infrastructure.
• Same window, farther north: San Luis Obispo County through Los Angeles County should expect "minor to moderate" flooding, with tides up to 8 feet.

What should coastal residents watch for?

The National Weather Service and Newport Beach officials, as quoted by the Guardian, point to a short list of practical steps for anyone near the coast this week:

• Stay off beaches during high tide windows — waves will run farther up the sand than usual.
• Keep extra distance from the ocean generally, not just during the tallest tides.
• Avoid rock walls and jetties, which can take direct wave impact.
• Check flood-prone property now, including garages and low-lying entry points.
• Pick up free sandbags from city distribution points in affected areas such as Newport Beach.
• Watch for updated NWS advisories through Thursday, since the agency says conditions are already running above forecast in some spots.

The Guardian's reporting is based on National Weather Service statements and a Newport Beach city statement; no additional reporting is available at this time.