This is a potentially life-threatening situation. A coastal flood warning means that coastal flooding is occurring, is imminent or is expected in the next 12 hours. The NWS issued flash flood warnings in Los Angeles County for the Conejo Valley, the San Gabriel Mountains foothills, and the Santa Monica Mountains foothills, including Malibu. Moderate to locally heavy rainfall is expected to persist though this morning with widespread rainfall of one quarter to one third inch per hour. Local amounts of one-half inch per hour are possible.
Urban flooding is likely in low-lying areas, such as underpasses and intersections.
The warnings mean floods may be occurring or imminent, but no specific reports had been received. In Newport Harbor, Orange County sheriff's deputies moved several boats tied up near the mouth of the harbor, where large waves can snap mooring lines. In Laguna Beach, where big storms have flooded downtown streets in years past, fire stations handed out free sandbags. In Commerce, the California Highway Patrol briefly shut down all northbound lanes of the Santa Ana Freeway last night because of flooding. Officials said the storm forced the delay or cancellation of numerous flights into and out of Los Angeles International Airport.