The chance of thunderstorms in the forecast could bring heavy rain and hail. If there's heavy rain with an isolated thunderstorm over a burn scar area, mud and debris could come rushing down from the hillside.
The LA County Sheriff's Department said in a post on X, "Due to the recent fires, coupled with the low but possible occurrence of hail and thunderstorms, there is potential for small isolated debris and mudflow which could occur in burn areas with less than two years of recovery".
The potentially vulnerable locations include Mt. Baldy, Wrightwood, Big Pines, Agua Dulce and Santa Maria.
The Public Works Department will be monitoring these communities until the threat dies down.
This comes as Southern California firefighters continue to work in containing three massive wildfires.
The Bridge, Line and Airport fires are the three largest active wildfires in the state. Combined, they have scorched more than 117,500 acres and destroyed at least 234 structures, but crews have managed to make good progress on the flames amid cooler temperatures.
Containment for the Bridge Fire grew to 59% Friday, after evacuation orders were downgraded to a warning for the Mount Baldy and Wrightwood areas. About 73 structures were destroyed by that blaze.
In Riverside and Orange counties, the Airport Fire has destroyed 160 structures. Containment grew to 51% Friday.
The Line Fire's containment was 53% as of Friday morning. It remains the least destructive of the three fires, but it has scorched more than 39,000 acres in San Bernardino County.
Meanwhile, resource centers are to open for homeowners and businesses affected by this month's wildfires:
- Friday, Sept. 20 from 10a.m. to 8a.m. at the LA County Fairplex - 1101 W. Mckinley Avenue, Expo Hall 8, Pomona CA 91766
- Saturday, Sept 21 from 10 a.m. to 8 p.m. at The Way World Outreach, Hallmark Campus - 4680 Hallmark Parkway, San Bernardino, CA 92407
- Monday, Sept. 23 from 10 a.m. to 8 p.m. at The Way World Outreach, Hallmark Campus - 4680 Hallmark Parkway, San Bernardino, CA 92407