A winter storm, anticipated to be the strongest of the season to date, began dropping water over Southern California overnight into early Thursday morning, bringing a half-inch of rain to some areas in Orange County, the Inland Empire and the Los Angeles County mountains by sunrise.
In an area forecast update early Thursday, meteorologists said it is not the total rainfall that is the concern, but the intensity.
“Rainfall rates are the main concern and due to the increased chance of convective cells there is a higher probability of rainfall rates in excess of 1 inch per hour, which would very likely cause substantial debris flows if they occurred over a recent burn area,” forecasters wrote in a 3 a.m. update.
In preparation for the storm, which led to a flash flood watch by the National Weather Service for most of Los Angeles County and a flood watch in Orange County until Thursday night, officials issued several evacuation warnings for residents in recent burn areas due to the potential for mudslides or debris flows.
Those areas include:
- The Palisades fire area, including Getty Villa, Highlands, Bienveneda near Temescal Canyon Park, Reseda Boulevard and Marinette Road near Will Rogers State Park and Mandeville Canyon,
- The Sunset fire area in the Hollywood Hills, east and south of Runyon Canyon,
- The Hurst fire area near Sylmar, including Olive Lane in the Oakridge Mobile Home Park,
- The Airport fire burn scar in Orange and Riverside counties,
- The Highland area in San Bernardino County, near the 2024 Line fire burn scar, and
- Mt. Baldy and Wrightwood, near the Bridge fire burn scar.
Forecasters have said Thursday brings with it an 80% chance of moderate to heavy rain and overall; The storm could bring 2 to 4 inches of rain along the coasts and in the valleys, and 4 to 8 inches or more in the mountains and foothills
By 4:15 a.m., Coto de Caza in Orange County had already received more than a half-inch of rain, areas in the Los Angeles County Mountains had seen up to 0.67 inches and Porter Ranch was up to 0.87 inches, according to NWS data.
But the heaviest rainfall was expected to hit the Los Angeles area around mid-afternoon Thursday, forecasters said.
Following the passage of a cold front, expected to cross over Los Angeles in the early- to mid-evening hours, scattered showers were anticipated for Friday, tapering off in the late morning and into the afternoon, leading to a dry weekend, the NWS said.