The storm prompted evacuation orders, as officials warned of flash floods in burn-scarred areas near the Eaton and Palisades fires and cautioned drivers to stay off the roads.

As the downpour intensified Thursday, the National Weather Service issued flash flood and severe thunderstorm warnings for a swath of eastern Los Angeles County. The rain caused a rockslide and pushed mud onto the road in Malibu Canyon, and a large debris flow left about 8 inches (20 centimeters) of mud across a road in the Hollywood Hills.

“Recent research shows that debris flows almost always happen in Southern California after wildfires, and given that there are multiple wildfires and each of them is pretty large, really we’re in a situation where the next large rainfall event is almost certain to generate some sort of debris flow.”