Lightning-laced thundershowers moved into the Los Angeles Basin early Tuesday evening after treating the San Diego area to a spectacular electrical display and dampening scattered Southland communities.
The National Weather Service said that for the next couple of days "Los Angeles will continue to experience weather more typical of the tropics with periods of showers and thundershowers."
There were widespread reports of lightning- or weather-caused power outages Tuesday night. About 1,000 Southern California Edison Co. customers in the Agoura area were without power for the better part of two hours.
Radio Station KNX was knocked off the air for a second or two at about 8:30 p.m. because of an apparent lightning strike on its transmitter, a staff member said.
Heavy Rainfall, Lightning
Police in the Gardena area reported heavy rainfall and officials in San Pedro said lightning was flashing all around Los Angeles Harbor.
Lightning and the threat of erratic winds posed a new threat to the Castaic Lake area in the Angeles National Forest, where about 1,000 firefighters had seemed to be getting the upper hand on flames that had burned through nearly 12,000 acres of rough brushland.
After charring an estimated 12,000 acres in the inaccessible Ruby Canyon area, the Castaic Lake blaze was about 25% contained, with full containment expected by 6 p.m. Thursday, forest information officer Tom Horner said.
"The very high humidity has helped to get the fire to lie down quite a bit," Horner said, "so now we're directly attacking it, right at the fire edge."
Los Angeles County Fire Capt. Garry Oversby said the humidity was increased by both the flow of tropical moisture moving up from Baja California and by an onshore flow of fog in the Santa Barbara area.
As the showers and thundershowers moved into the San Bernardino Mountains and the deserts Tuesday afternoon, the state Department of Forestry reported at 3 p.m. that there had been 840 ground strikes of lightning during the preceding 11 hours in San Diego, Imperial and San Bernardino counties.
The intense lightning display caused power outages for about 225,000 customers of San Diego Gas & Electric Co. in the San Diego area, where .31 of an inch of rain was recorded by 4 p.m.
With a high-level low-pressure system stalled over San Diego and drawing in moisture from Mexico, the prediction was for more showers and thundershowers in Southern California for a couple of days.
The muggy, tropical weather pushed the temperature up to 99 degrees at the Los Angeles Civic Center on Tuesday, the last day of summer. there by late in the day, but a 20% chance of showers was forecast for the entire Los Angeles area during the night.
The hottest section of the Castaic Lake fire, meanwhile, remained the northeast sector, where 10 helicopters and eight air tankers supported the firefighters until nightfall.
The fire erupted Sunday morning and was driven by light Santa Ana winds. The cause was under investigation. Although winds blew it away from the community of Lake Hughes, the blaze burned a U.S. Forest Service lookout tower at Warm Springs.
No other structures were reported burned.
Times staff writers Richard A. Serrano in San Diego and Nieson Himmel in Los Angeles contributed to this article.