A mud slide destroyed most of the Yuima Water District Building and forced the closure of parts of California 76 in Valley Center on Thursday after heavy rains raced down Palomar Mountain, denuded by a recent fire.
Two water district employees escaped injury, and no injuries were reported to other residents of the area, a spokesman for the California Department of Forestry said.
Elsewhere in San Diego County, intermittent rains contributed to many traffic accidents, including an eight-car pile-up shortly after 7 p.m. on Interstate 15 near Ocean View Boulevard. A dozen people were injured, according to a spokeswoman for the California Highway Patrol, and 10 were sent to area hospitals. Two of the victims were listed in stable condition at Mercy Hospital.
"Thursday's storm only dumped 0.06 of an inch at Lindbergh Field," National Weather Service forecaster Wilbur Shigehara said. "We're expecting much heavier rainfall from Sunday's storm that should see us through the early part of next week."
Until then, Shigehara said, San Diegans can look forward to partly cloudy skies with only a 20% to 30% chance of scattered showers today and Saturday.
The rain is the result of a low-pressure system that is moving in from the central Pacific and is picking up tropical moisture from Hawaii, said Mike Smith, a meteorologist at WeatherData, which provides forecasts for The Times.
In Valley Center, that low-pressure system dumped 1 1/2 inches in less than an hour over portions of bare Palomar Mountain, said Chris Hess, the CDF fire captain dispatcher.
"Because of all the devastation of the Palomar fire . . . the erosion process is occurring much faster than usual," Hess said. "There is no vegetation on the mountain to collect and absorb the rain, so it (mud) is just coming down."
Mud Pushed Out Furniture
The mud slide rolled through the front door of a corrugated metal water district building, pushing a desk and chair out the back of the building. The mud destroyed 75% of the building, Hess said.
In some cases, the mud from Palomar Mountain was 12 to 18 inches deep, and it swept along pieces of burned wood and boulders as big as four feet. CDF firefighters worked to remove files, computers and furniture from the building, at the base of the mountain, before they were warned to leave because rain had started again by 5 p.m.
Mud slides also covered portions of Rincon Ranch Road, just east of Valley Center, and workers from the California Department of Transportation were able to open one lane of the road by 3:15 p.m., a Caltrans spokeswoman said.
The intersection of California 76 and County Highway S6 was closed for several hours as well before county and Caltrans crews cleared the debris and boulders that had slid down from Palomar Mountain.
Rain also felled power lines and washed out power poles in Pauma Valley, leaving 419 San Diego Gas & Electric Co. customers without power for about two hours, said Karen Duncan, an SDG&E spokeswoman. Power was restored to all but six customers by 3:30 p.m.
At 6:48 p.m., SDG&E received the first call of an outage affecting 921 customers around Sharp Memorial Hospital, according to Everett Langlais, an SDG&E spokesman.
Lightning apparently hit a transformer. SDG&E sent an underground crew to replace the transformer, but Langlais didn't say when power would be fully restored.
Sharp Memorial Hospital, among those affected, lost power during visiting hours around 7 p.m. Emergency power kicked in in a matter of seconds, according to Sharp spokeswoman Eileen Hale, who said the outage presented no problems. Power was restored at 7:50 p.m.
Power was also out in the Mission Hills and Hillcrest areas about 7:15 p.m., after power lines caught fire from a nearby tree struck by lightning, Langlais said.
She said 1,753 customers were affected and power for two-thirds of them was restored about 8:15, leaving 500 customers in darkened buildings.
Meanwhile, temperatures in San Diego on Thursday climbed to 72 degrees at Lindbergh Field, with a low of 66. Normal highs for this time of year are about 74, with lows about 59.
Minor Fog Predicted
Fog--expected to be minimal, however--will hover over mountain slopes, "though the sun should burst through in the afternoons," Shigehara said.
Mountain highs will be in the mid-60s, with lows dropping to around 57 degrees through Sunday. Desert dwellers will enjoy sunny skies on Saturday, but there will be cloudy skies today and Sunday.
Coastal highs should reach 63 through the weekend, with partly cloudy skies today and Saturday. Lows along the coast will be from 55 to 60.
The surf will be 1 to 3 feet; ocean temperatures will be near 59.
Inland valley highs will be in the upper 70s, with lows around 59 to 64.
Times staff photographer Don Bartletti contributed to this story.