Lightning storms were moving westward over San Bernardino, Riverside and San Diego counties Saturday and were expected to extend into Los Angeles County by the evening, forecasters said.
Cloud-to-ground lightning was expected at San Diego County beaches around midday Saturday, according to the National Weather Service. The agency also issued a flood advisory for central Riverside County for midday Saturday, as a complex network of thunderstorms moved slowly through an area between Palm Springs, Idyllwild and Banning.
The thunderstorms could extend into the Los Angeles Basin and the San Gabriel Valley through Sunday evening. Such isolated weather systems could produce "heavy downpours, gusty winds and deadly lightning," the weather service said.
One person was killed and several others injured by lightning strikes at Venice Beach and on Catalina Island last Sunday during an unusual summer thunderstorm.
Meanwhile, flooding is possible on roads and in dry arroyos, the weather service warned. Even if storms are far away, the dry washes could be hit by flash flooding.
Authorities warned anyone outdoors, such as those at the beach or picnicking, to quickly head to their cars or indoors should they see lightning or hear thunder.
"When thunder roars, go indoors!" the weather service said.
Lightning kills more people each year than tornadoes or hurricanes, according to the Red Cross, which offered the following safety tips if you find yourself in a thunderstorm:
—At the beach? Get out of the water at the first sight of lightning or hearing the first sound of thunder. Go inside or head to your car.
—Picnicking? Go to your car or inside a building, or at least avoid tall isolated trees and other metal objects, like fences or bleachers. Picnic shelters and sheds are not safe.
—Driving? Park. Stay inside, turn on emergency flashers and wait until heavy rain ends. Avoid touching metal or anything else that conducts electricity inside or outside the vehicle.
—Don’t shower or bathe during a lightning storm.
—Stay inside for at least half an hour after the last thunderclap.
Temperatures at the beaches this weekend were expected to be in the upper 70s, the 80s in downtown Los Angeles, and the 90s in the San Fernando and San Gabriel valleys. Forecasters said there was a 20% chance of rain Saturday night, moving up to a 40% chance on Sunday.
Follow me for more breaking news on Twitter: @ronlinCopyright © 2015, Los Angeles Times