A moisture plume moving north from Baja California and a low-pressure zone traveling south over Southern California combined Friday to give Ventura County its first rain since mid-October.

The last time the National Weather Service reported measurable rain in the county was Oct. 12, when Camarillo recorded about 0.10 of an inch, said Stuart Seto, a weather specialist with the National Weather Service in Oxnard.

On Friday, Simi Valley recorded about a half-inch of rain, while most parts of the county got 0.10 to 0.25 of an inch, Seto said. A mass of cold air was expected to displace the storm today, he said.

The rain was enough to cause the Weather Service to issue a flash flood watch Friday for recently burned areas. While heavy rains were not expected, burned areas near Fillmore and Moorpark could be vulnerable to mudslides when rain falls at a rate of a half-inch per hour, authorities said.

Capt. Barry Parker of the Ventura County Fire Department advised residents in recently burned areas to prepare sandbags in case of heavy rain in the future.

Friday's light rain, however, wasn't enough to make the county's tinder-dry vegetation less vulnerable to fast-moving wildfires, Parker said. "Essentially what this small storm has done is knock the dust down."

It also contributed to a rise in traffic accidents as commuters drove too fast on slick roads Friday, he said. One fatal accident was reported in Thousand Oaks, although it was not clear if the cause was weather-related.

Firefighters are still waiting for new green growth on hillsides to signal the end of the high fire season.

"As long as we are seeing brown, that means there's dead brush out there that's ready and accessible to burn," Parker said. "We're still in a critical state."

The light rain didn't do much to help firefighters with a blaze that burned more than 3 acres of brush in the Ventura River bottom Friday morning, said Battalion Chief David Frost of the city of Ventura Fire Department. Firefighters were still working to put out the embers Friday afternoon.

Temperatures were expected to drop by up to 5 degrees over the weekend, but no more rain was on the horizon, Seto said.

Seasonal rainfall totals are far below normal in Ventura County so far. Since July 1, Camarillo has had about a third of an inch of rain, Seto said. Normally at this time of year, it should be about 2 inches.

The region is in a La Niña weather pattern, with a 50 percent chance that rainfall will be below normal this winter, he said.

Elsewhere in Southern California, flash flood warnings and watches were issued Friday where wildfires have stripped vegetation from thousands of acres in San Diego and Orange counties.

Residents were ordered to leave 200 homes in Orange County's Modjeska and Williams canyons, while voluntary evacuations were urged in Silverado Canyon. In San Diego County, more than 2 inches of rain fell in areas burned by the Poomacha and Rice wildfires of late October.