Los Angeles County residents living in recent burn areas are being urged to prepare for potential mudslides and flooding as a storm system brings heavy rain through the weekend and possibly into next week.
A Flood Watch is in effect from late tonight through Saturday evening, with recent burn areas—including those impacted by the January wildfires—remaining highly susceptible to mud and debris flows. Ahead of the storm, the Office of Emergency Management and law enforcement agencies warned residents in at-risk areas to evacuate.
Los Angeles County Sheriff's Deputies are conducting targeted outreach, including door knocks, to pre-identified vulnerable residences to notify them of evacuation warnings and orders, which will go into effect at 8 p.m. tonight.
Residents in burn scar areas are urged to stay vigilant, monitor official weather updates and avoid unnecessary travel during the storm—especially if they have been advised of potential mudflow risks in their neighborhoods.
All residents are encouraged to sign up for emergency alerts at alert.lacounty.gov and download the Genasys Alert mobile app or visit genasys.com to view their evacuation status. The county is directing residents to find the nearest sand and sandbag distribution site at https://pw.lacounty.gov/dsg/sandbags/ and to view the Los Angeles County Public Works mud and debris flow forecast for their area at https://dpw.lacounty.gov/wrd/forecast/index.cfm.
Officials are urging residents to have an emergency plan in place that is easy for all family members to understand and to be prepared to leave immediately if an evacuation is ordered. Residents should identify important items to take if their neighborhood is evacuated, including photos, important documents, medications and other essential items for their family and pets.
During and after the storm, residents are strongly encouraged to stay away from flood control channels, catch basins, canyons and natural waterways, which are vulnerable to flooding during periods of heavy rain. Officials warn residents not to attempt to cross flooded areas and never to enter moving water on foot or in a vehicle.
The Winter Shelter Program has been activated, with augmented winter shelters now open for unhoused residents. Locations are listed at lahsa.org/winter-shelter. Residents can call 2-1-1 for bed availability and transportation information.
The Sheriff's Homeless Outreach Services Team has continued to engage unhoused individuals residing in and around local waterways to inform them of the storm and offer supportive services to help them prepare.
A powerful low-pressure system is forecast to bring heavy rain, gusty winds and possible thunderstorms to the Los Angeles area beginning Thursday night and continuing through the weekend, with mountain areas potentially receiving up to 4 inches of rainfall, according to the National Weather Service.
The storm is expected to reach Los Angeles County Thursday night, with most areas seeing 1 to 2 inches of rain through Friday. Mountain and foothill neighborhoods, including the Santa Monica Mountains and surrounding canyons, could receive 2 to 4 inches, with some models suggesting totals as high as 5 inches in specific locations.
"Periods of moderate to heavy rain are expected Thursday through Saturday, and possibly into early next week, as a storm system moves into the region," forecasters wrote in a weather discussion Wednesday morning. "Quite a bit of uncertainty in the progression of the storm exists, and widespread flooding is not out of the question."
The National Weather Service issued a Slight Risk of excessive rainfall—level 2 of 4—for the area on Friday. Rain rates could reach a quarter to half inch per hour, with isolated areas potentially seeing three-quarters of an inch per hour.
Forecasters warn of a 10 to 20 percent chance of thunderstorms, which could produce heavy downpours, small hail and gusty winds. There is also a very small but non-zero chance of a weak, brief tornado.
Marine conditions will also become hazardous, with a large west-northwest swell bringing high surf to coastal areas Thursday through Saturday, with waves reaching 8 to 11 feet in Ventura County.
Residents should prepare for potential travel delays, localized street flooding and increased flows in creeks and streams. Drivers should watch for blown palm fronds, rockslides, mudslides on canyon roads and ponding water on local streets.
The National Weather Service advises residents to monitor forecasts, clear gutters, check windshield wipers and avoid outdoor activities Thursday through Saturday. Residents should not drive through flooded roads and should go indoors if thunder is heard.
The Sheriff's and Fire Departments have activated key resources, including Search and Rescue Teams and air resources staffed with swiftwater rescue swimmers. Incident Management Teams are on alert and resources have been strategically pre-positioned.