An unseasonably cold storm brought its first band of moderate rain to Southern California on Thursday afternoon and was expected to produce scattered showers throughout the day, forecasters said.
The late-season storm, which originated in the Gulf of Alaska, was likely to bring rain and lightning to parts of Los Angeles, Orange and Ventura counties through the early evening before diminishing overnight, said Stephen Harrison, a meteorologist with the National Weather Service in Oxnard.
"They're not producing a whole lot of rain, but it's enough to wet the ground," Harrison said Thursday afternoon.
The precipitation was expected to be heaviest on Friday, especially during the morning rush hour, Harrison said. The storm was most likely to produce isolated thunderstorms on Friday, as well as brief heavy rain, lightning and small hail, he said.
Forecasters warned of possibly hazardous driving conditions due to slippery roads from accumulated oil on wet pavement.
The system is expected to taper off by Saturday, forecasters said.
The weather service cautioned residents in the foothills around the Colby, Powerhouse and Springs fire burn areas to prepare for the rain. The burn-scarred areas are susceptible to short, heavy bouts of rain, especially after years of drought, the agency said.
The storm could also mean a windy, dusty couple of days for residents of the Antelope Valley, forecaster said, with the worst of the system is expected to pass over by Friday night.
Conditions in the mountains will be winter-like through Friday, according to the weather service. Wind gusts in local mountains, including Big Bear, could top out at 45 mph with snow dropping down to elevations as low as 5,500 feet.
The weather forced organizers of the Amgen Tour of California cycling race to cancel time trials set for Friday on Big Bear and move them to Santa Clarita.
The rainfall, while welcome, is not expected to have any significant effect on California's lingering drought.
"Anything that goes into the groundwater and keeps people from watering their lawns is good," said Kathy Hoxsie, another weather service meteorologist. "It won't make a notable dent in what we need, but everything helps."