Homes were evacuated as a swift storm with expected heavy rain moved toward drought plagued Southern California, bringing worries of mudslides where recent wildfires left mountainsides exposed.
The storm's full force was expected to be felt Friday morning, with possible thunderstorms and rains up to an inch per hour, the National Weather Service said.
A 10-mile stretch of the Pacific Coast Highway was closed overnight in Ventura County because of a high likelihood of rock slides in an area made bare by last year's Springs Fire in Camarillo, the California Highway Patrol said.
On Thursday, mandatory evacuation orders were issued for about 1,000 homes in Glendora and Azusa, eastern foothill suburbs of Los Angeles that sit beneath nearly 2,000 acres of steep mountain slopes stripped by another fire in January.
"We have an hour to get evacuated," said Dana Waldusky as she hurried to evacuate the family home next to the burn area in Glendora. "We're just boarding up all our doors."
Waldusky, 22, said she, her parents and sister made sure they had important documents, photos, medicines and their toothbrushes packed.
"Last time, at the fire, we had 15 minutes, so this time we made sure we were prepared," she said.
The home survived the fire, which firefighters stopped 15 feet from their back fence.
"This time there's nothing you can do. You can't stop water," she said.
As a lighter storm moved through the area earlier in the week, residents focusing on Friday built barriers of wood and sandbags to keep debris flows in streets and out of homes.
While concern was highest in the Glendora-Azusa area, meteorologists also posted flood watches for many other areas denuded by fires over the past two years.
Cities in Santa Barbara and San Luis Obispo counties were handing out sandbags in anticipation of heavy rain.
Even waterspouts offshore and small tornados were possible, the NWS said.