May 07--A slow-moving storm system that has already wreaked havoc on roadways will continue to pepper Southern California with rain and even possible thunderstorms Saturday, officials at the National Weather Service said.
Forecasters warn that there is a 20% chance of thunderstorms, which could generate heavy rain and subsequent flash flooding. They issued a flash flood watch through 8 p.m. Saturday for the mountains of Los Angeles, Ventura and Santa Barbara counties as well as the Antelope and Cuyama valleys.
Much of the region is expected to get less than a quarter-inch of rain, but some hard hit areas got more than an inch on Friday. Thunderstorms could also bring gusty winds and hail.
Saturday morning and afternoon represent the "best threat" for thunderstorms, said National Weather Service meteorologist Robbie Munroe. The showers, he added, could linger into Sunday.
"If you come across swift moving water crossing the roadway, make the safe choice and find an alternate route," a weather service statement said. "Turn around, don't drown."
Late Friday afternoon, the California Highway Patrol had to shut down Interstate 5 through the Grapevine after the storm sent water, rocks and mud rushing across the freeway, temporarily trapping several drivers in their vehicles.
The CHP reopened all lanes Friday night, but at least initially, vehicles were being escorted through the affected area.
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Forecasters have also reported large hail near Sacramento and lightning across the Bay Area, all generated by the same storm system.
Munroe said storms like this are "not unprecedented" in Los Angeles, "but we don't get something like this every May."
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