Los Angeles County officials said Thursday they have cleared flood channels, readied dams and begun going door to door in wildfire burn areas as the region braces for what could be an exceptionally strong El Niño winter, even as a weather forecaster cautioned that no one knows how much rain will fall.
"This is not about predicting exactly where or when a storm will hit," said Supervisor Hilda Solis, chair of the county Board of Supervisors, at a news conference at the Hall of Administration marking the start of the 2026-27 storm season. "It's about making sure that we're prepared for what could come and have the resources and coordination in place, ready to meet those challenges."
Solis proclaimed a local emergency Sept. 23, and the board ratified it this week. She said the proclamation lets the county move resources quickly, coordinate mutual aid and seek state and federal assistance. The governor has also proclaimed a statewide emergency.
"We're not going to wait for flooded roads, evacuation orders or power outages to figure out who is responsible for what," Solis said.
Ariel Cohen, meteorologist in charge of the National Weather Service's Los Angeles office, said ocean temperatures in the tropical Pacific are significantly above normal, but how that will shape Southern California's weather is far less certain.
"El Niño is an oceanic temperature signal," Cohen said. "It is not a storm, it is not an atmospheric river, and it is not a weather forecast for Los Angeles County."
Very strong El Niño events historically raise the odds of wetter-than-normal conditions, flash floods, burn scar debris flows and coastal flooding, he said. But the pattern does not guarantee rain, and a significant heat wave is on the way.
"A strong El Niño shifts the probabilities," Cohen said. "It does not determine exact outcomes."
Mark Pestrella, director of LA County Public Works, said the department began assessing flood risk in about April. They have emptied debris basins, cleared channels and readied the county's 14 dams, working with the Army Corps of Engineers. The system is designed for about a 100-year event, one with a 1% chance of occurring in any given year.
The top priority is land burned in the past five years, including the Palisades and Eaton fire areas, where hillsides have not healed enough to handle heavy runoff. Public Works staff are advising property owners there door to door about their risk, and some vulnerable roads may be closed during storms.
Pestrella urged drivers to obey closures, noting serious incidents in North County last year, including some fatalities, when people tried to cross a waterway or go through mud.
"Last year, we lost 140 people in the United States to flooding," he said. "More than half of those people were driving their vehicles."
Sheriff Robert Luna said deputies will patrol regularly near burn scars, and the department's homeless outreach team will contact people living in riverbeds and washes before major storms.
Jon O'Brien, chief deputy of emergency operations for the county Fire Department, spoke on behalf of Fire Chief Anthony Maroney. He said ready-to-fill sandbags are available at all 176 county fire stations, with sand at select sites. Residents can check availability at ready.lacounty.gov/rain.
"If officials tell you to evacuate, leave promptly," O'Brien said. "A rescue becomes much harder once roads and access ways are flooded."
Kevin McGowan, director of the Office of Emergency Management, said the county will activate its emergency operations center early. He warned that red flag fire weather remains possible, typically peaking from November through January.
"If you receive an alert, follow it, heed the alert, regardless of who's sending it," McGowan said.
Leepi Shimkhada, chief program officer for the Department of Homeless Services and Housing, said outreach teams are working to move people near flood channels indoors. When winter shelters scale up, people can call 211 for motel vouchers and bed information.
The Aging and Disabilities Department will deliver home meals ahead of expected storms, Director Maral Karaccusian said. Jackie Contreras, director of Public Social Services, said about 1,000 county employees have completed American Red Cross shelter training.
Gary Jones, director of Beaches and Harbors, said crews will begin building seasonal berms at Dockweiler, Venice and Zuma beaches next week, a month and a half earlier than the usual mid-November start.
Dr. Muntu Davis, the county health officer, urged residents who rely on powered medical equipment to plan for outages, to run generators only outdoors and to stay out of the ocean for at least 72 hours after rain.
"It's better to have it and not need it than need it and not have it," Davis said, recalling his father's advice.
Officials directed residents to ready.lacounty.gov.
"The cost of being unprepared can be much greater than the cost of being overprepared," Cohen said.