There were more than 200 lightning strikes in San Diego County since Friday, with nearly 140 on Sunday, according to the National Weather Service.
Thunderstorms that started Sunday morning at the county’s coast moved inland by afternoon and led to the weather service issuing a flash flood warning for northern parts of San Diego County and southwestern Riverside County.
The warning was in effect until 5:45 p.m., according to the weather service. About 2:45 p.m., radar showed a thunderstorm about six miles east of Palomar Mountain, and a National Weather Service spotter reported four-tenths of an inch of rain coming down in 10 minutes at Sunshine Summit, near the mountain.
The California Highway Patrol also closed state Route 79 in both directions at mile marker 46.5 because of flooding.
Earlier in the day, a small band of thunderstorms doused the county's coastline and triggered lightning warnings at Lindbergh Field that lasted until about noon.
"Thirty lightning strikes were detected over and off the coast," the weather service said on Sunday. By Monday, 138 lightning strikes were reported.
According to San Diego Gas & Electric, the storms knocked out power in at least five locations, leaving about 1,000 customers without power. The outages were in Ocean Beach, Encinitas, Logan Heights, Torrey Pines and Mission Valley.
Lightning over San Diego Bay. 7/27/15 #sandiegolightning #SoCalLightning pic.twitter.com/E1uTs029GT
— Hugh Ryono (@HugeRhino) July 28, 2014
The CHP reported some roadway flooding in the morning in the right-hand lanes of northbound Interstate 805 approaching Interstate 5 near Carmel Valley.
An urban small stream flood warning also was issued in the morning for the coast from Camp Pendleton to San Ysidro.
The overcast, humid weather is expected to continue Monday.
While no one was injured in the San Diego County storms, one person died in Los Angeles County from a lightning strike, according to the Associated Press.
The 20-year-old man was one of 14 people to be struck by lightning at popular Venice Beach in Los Angeles and on Catalina Island.
Los Angeles County coroner's Lt. Larry Dietz said the man was taken from the beach and died at a hospital in the afternoon.
Dietz said he couldn't confirm whether the man was a swimmer who was pulled from the water and given CPR.
Thirteen people, including a 15-year-old boy, were jolted by lightning at the beach as rare summer thunderstorms hit Southern California.
Nine went to hospitals, including one who remained in critical condition.
Lightning also struck a 57-year-old man on a golf course on Catalina Island, but he was taken to a hospital in stable condition.