A widespread elevated thunderstorm event occurred  across northern San Diego, Orange, western Riverside and southwest San Bernardino counties lasting up to 24 hours and producing 2500 cloud to ground strikes (4000 total flashes) over the land and California bight waters. Toward the end of the episode thunderstorms affected southern San Diego county. An upper level trough approached the coast and tapped subtropical moisture from the south. The main area of showers and thunderstorms was oriented southwest to northeast from northern San Diego County and Orange County through the Inland Empire and up into San Bernardino County high deserts, training over this area for most of the day and night of the 23rd. Two-day rainfall totals were from one-quarter to one inch for most areas and locally just over one inch on the coastal slopes of the San Bernardino mountains. San Diego county had the least with 0.25 or less and the most was the greater Riverside area with up to an inch of rain. Minor street flooding occurred in Orange and Riverside Counties.  Several power poles were downed or burned due to lightning strikes. One strike hit a football player practicing at Grossmont High School in El Cajon, but he survived.

Lightning in RIVERSIDE, CALIFORNIA
From 24-OCT-16 07:00:00 to 24-OCT-16 08:00:00 (PST-8)
Location: WOODCREST
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a fire due to power lines downed from a lightning strike.

Lightning in RIVERSIDE, CALIFORNIA
From 23-OCT-16 19:00:00 to 23-OCT-16 20:00:00 (PST-8)
Location: CORONA
Property damage: 6.00K
Crop damage: 0.00K
Reported by: Public

Multiple utility poles down, likely caused by frequent cloud to ground lightning.

Lightning in SAN BERNARDINO, CALIFORNIA
From 23-OCT-16 19:30:00 to 23-OCT-16 20:15:00 (PST-8)
Location: APPLE VLY
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Multiple power lines and transformers damaged by lightning strikes.

Lightning in SAN BERNARDINO, CALIFORNIA
From 24-OCT-16 07:00:00 to 24-OCT-16 08:00:00 (PST-8)
Location: APPLE VLY
Property damage: 12.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several power poles down across streets in Highland, with lines down across yards, likely due to a lightning strike. Lightning struck a power pole, pole and lines down on roadway southeast of Apple Valley.

Flood in SAN BERNARDINO, CALIFORNIA
From 24-OCT-16 10:30:00 to 24-OCT-16 11:30:00 (PST-8)
Location: YUCCA VLY GNT RCK AR
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The southbound lane on Highway 247 at Larrea Road was completely flooded.

Lightning in SAN DIEGO, CALIFORNIA
From 24-OCT-16 15:00:00 to 24-OCT-16 15:30:00 (PST-8)
Location: RAINBOW
Property damage: 1.50K
Crop damage: 0.00K
Reported by: Department of Highways

Lightning struck a tree which caught on fire.

Lightning in SAN DIEGO, CALIFORNIA
From 24-OCT-16 17:30:00 to 24-OCT-16 18:30:00 (PST-8)
Location: LA MESA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

A teenage football player was sent to the emergency room after getting struck by lightning at Grossmont High School. The player survived the strike.