A powerful autumn storm is expected to bring its heaviest rainfall to parts of the Southland on Thursday, with thunderstorms and possible flooding threatening communities along the Malibu coast and in the Santa Monica Mountains. The storm moved into Los Angeles County on Wednesday, with National Weather Service (NWS) forecasters warning that conditions could intensify Thursday as the center of the weather system approaches Southern California.
The NWS stated that the Santa Monica Mountains and adjacent coastline remained under a flood watch through Thursday due to the area's south-facing aspect. This flood watch specifically includes Malibu, Malibu Bowl, Pacific Palisades, Topanga, and portions of the eastern and western Santa Monica Mountains, and is scheduled to remain in effect through Thursday afternoon. NWS forecasts also indicated the potential for rapidly developing thunderstorms and a "small risk (around 5%) of a weak tornado."
The storm has the potential to produce flooding in urban and poorly drained areas, including streets, creeks, and rivers. Areas near steep hillsides and recent wildfire burn scars could face additional hazards from runoff, mud, and debris. Forecasters noted that overall rainfall totals from the multiday storm could average about 1.5 inches across much of Los Angeles County, with 2 to 3 inches possible in areas where terrain enhances rainfall or thunderstorms produce concentrated downpours. Orange County is also expected to receive periods of rain, with isolated thunderstorms possible as the storm moves through Southern California. Snow is unlikely below 8,000 feet.
Along the coast, the NWS warned that showers and isolated thunderstorms could affect ocean waters through Thursday, potentially producing lightning, erratic wind gusts, locally rough seas, and waterspouts. A beach hazards statement remains in effect through late Thursday night for portions of the Los Angeles County coastline, where elevated surf and dangerous rip currents are expected. Minor beach erosion and tidal overflow are also possible in low-lying areas. Los Angeles County health officials issued an ocean water quality rain advisory through at least 3 p.m. Saturday, cautioning residents to avoid contact with ocean water, particularly near storm drains, creeks, and rivers that can carry bacteria and debris into the ocean.
Dry and warmer conditions are expected to return Friday and continue through the weekend, with a weak Santa Ana wind pattern developing as the storm moves out. Forecasters said offshore winds are expected to remain mostly below advisory levels, although some gusty conditions could occur in wind-prone areas. Ahead of the storm on Wednesday, Los Angeles city crews worked to reinforce barriers, shore up vulnerable hillsides, and clear debris from neighborhoods and wildfire burn areas.
Under an emergency executive order issued following the January 2025 wildfires, Public Works crews continued mitigation efforts in Pacific Palisades, including providing sandbags and installing more than 13,000 feet of K-rail barriers. The Los Angeles Fire Department had specialized resources available for swift-water rescues and other storm-related emergencies, while police officers were prepared to assist with evacuations if necessary, according to city officials. Los Angeles Homeless Services Authority teams also conducted outreach to unhoused residents, providing weather-related safety information and supplies.
Street maintenance crews were placed on standby to respond to roadway problems, while the Department of Transportation and Bureau of Engineering continued monitoring areas vulnerable to landslides. The Bureau of Sanitation was also monitoring the city’s wastewater system and maintaining debris basins in the Palisades area. Mayor Karen Bass stated Wednesday that heavy rain and strong winds could quickly flood streets, bring down trees and power lines, and cause dangerous mud and debris flows in burn areas like the Palisades, adding that the city was "taking action now to keep Angelenos safe." City officials encouraged residents to sign up for emergency notifications through NotifyLA, review family emergency plans, and prepare essential supplies. Free sand and sandbags were available at fire stations.
