South Bay beachgoers face moderate coastal flooding through Tuesday as the National Weather Service warns that evening high tides and swells from Hurricane Marie will push seawater onto low-lying shoreline areas.

The NWS Los Angeles/Oxnard office issued the coastal flood advisory Thursday, Sept. 3, at 12:11 p.m. It takes effect Saturday, Sept. 5, at 6 a.m. and runs through Tuesday, Sept. 8, at 11 p.m. The advisory covers Manhattan Beach, Hermosa Beach, Redondo Beach and El Segundo as part of the broader Los Angeles County Beaches zone.

A companion high surf advisory covers the same period.

What to expect

The NWS said high tides will hit around 5 p.m. Saturday, 6 p.m. Sunday, 7 p.m. Monday and 8 p.m. Tuesday. Around those times, seawater is likely to flood parking lots, beaches and walkways. The agency said significant damage to roads or structures is not expected.

Hurricane Marie is tracking away from the California coast but is still generating a 6-to-8-foot south swell, the Los Angeles Times reported. That swell is arriving during a stretch of elevated evening high tides. NWS Los Angeles meteorologist Ryan Kittell told the San Francisco Chronicle that high tides near 7 feet on Sunday and Monday are "usually the starting point to where we get concerned for coastal flooding."

Kittell said the combination raises concern for enhanced coastal erosion and possibly some isolated flooding, "especially for any south-facing coastlines."

South Bay breakdown

Not every stretch of sand faces the same risk. Los Angeles County Fire Department Lifeguard Division spokesman Pono Barnes told the Orange County Register that south-facing Manhattan Beach will see moderate surf, while Redondo Beach and Hermosa Beach will have smaller waves.

Crowd size is the bigger worry. The weekend before, more than a million people visited LA County beaches, and lifeguards performed more than 1,200 ocean rescues and responded to nearly 400 medical emergencies, the Register reported.

"There's just tons of people, there's just going to be tons of rescues," Barnes said.

Safety guidance

The NWS urged beachgoers to stay out of the water or swim only near occupied lifeguard towers. The agency warned that rock jetties can be deadly in these conditions and that drivers should not go around barricades or through water of unknown depth.

Residents can check for updates on the NWS Los Angeles forecast office website.