Subtropical moisture from the remnants of Hurricane Linda brought widespread showers to most of the area, deserts included. The first isolated thunderstorm developed on the 6th in San Diego County as a moisture surge in monsoon warm upper level flow arrived. Intense heavy rain from thunderstorms occurred on the 7th with flash flooding in several locations including Victorville and Forest Falls. A swift water rescue in Victorville was successful, but another incident in Forest Falls had one rescue but a drowning occurred when a 30-year-old couple crossed Mill Creek and were swept away. Most areas received between a few hundredths to one-third of an inch of rain, with a few upslope areas of the San Bernardino Mountains receiving up to around one inch. Additional thunderstorms developed on the 8th by noon over the mountains and quickly spread into the Inland Empire and Orange County, as well as near I-15 in San Diego County. Locally heavy rain and several trees and poles were downed in the Riverside area including a small dust storm. Several hail reports, mostly nickel-sized, but a few larger. Activity decreased on the 9th with only isolated thunderstorms formed.

Flash Flood in SAN DIEGO, CALIFORNIA
From 07-SEP-15 15:00:00 to 07-SEP-15 16:30:00 (PST-8)
Location: MT LAGUNA AFS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported mud and rocks on Highway 78 near Yaqui Pass, closing Highway 78. CHP also reported flash flooding Highway S2 from mile marker 36 to mile marker 44, blocking the southbound lanes.

Hail in SAN DIEGO, CALIFORNIA
From 08-SEP-15 12:30:00 to 08-SEP-15 14:00:00 (PST-8)
Location: WHISPERING PINES
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported quarter-sized hail and extremely heavy rain.

Flash Flood in SAN DIEGO, CALIFORNIA
From 08-SEP-15 14:00:00 to 08-SEP-15 15:00:00 (PST-8)
Location: SAN FELIPE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a rock/mudslide blocking the roadway at Highway S-22 near San Felipe Road.

Hail in RIVERSIDE, CALIFORNIA
From 08-SEP-15 16:00:00 to 08-SEP-15 16:30:00 (PST-8)
Location: BEAUMONT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reported quarter-inch hail.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 08-SEP-15 17:30:00 to 08-SEP-15 19:00:00 (PST-8)
Location: THORN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Multiple swift water rescues along Bear Valley Road. Water flowed fast down the road with some areas of water around 5 feet deep. A spotter reported water 4-6 deep at the intersection of Bear Valley Road and Apple Valley Road.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 09-SEP-15 11:00:00 to 09-SEP-15 12:00:00 (PST-8)
Location: FALLSVALE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Valley of the Falls Drive is washed out and the road was closed.

Lightning in SAN BERNARDINO, CALIFORNIA
From 09-SEP-15 13:00:00 to 09-SEP-15 13:30:00 (PST-8)
Location: RAINBOW
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a lightning-started brush fire along Highway 38 near Onyx Peak.

Thunderstorm Wind in RIVERSIDE, CALIFORNIA
From 09-SEP-15 13:30:00 to 09-SEP-15 14:15:00 (PST-8)
Location: PERRIS
Magnitude: 43.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a power pole down with live wires in the roadway near the intersection of Cowie Avenue and Lopez Road.

Flood in RIVERSIDE, CALIFORNIA
From 09-SEP-15 14:45:00 to 09-SEP-15 15:15:00 (PST-8)
Location: PERRIS
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported vehicle stuck in flood waters at Marshall Street and Lopez Road.

Flash Flood in RIVERSIDE, CALIFORNIA
From 09-SEP-15 14:00:00 to 09-SEP-15 15:00:00 (PST-8)
Location: AGUANGA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

An NWS employee reported a flash flood on Highway 79 in Aguanga leaving 1 foot of mud on the roads. Crews were still cleaning up mud the following day.

Flash Flood in ORANGE, CALIFORNIA
From 09-SEP-15 15:00:00 to 09-SEP-15 16:00:00 (PST-8)
Location: SANTA ANA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A male and a female were in a flood control channel and had to be rescued by the Orange County Fire Department when they were caught off guard by the quickly rising water.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 08-SEP-15 16:00:00 to 08-SEP-15 18:00:00 (PST-8)
Location: FOREST FALLS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

A flash flood at Mill Creek crossing...40 feet wide and 8 to 12 inches deep. The head of the flash flood was 3 to 4 feet deep. From Victor Valley news group: flood waters overtook a couple hiking. An off-duty sheriff's deputy heard the couple calling for help and was able to save the young woman, but the man was swept away. The body of the victim, a Rancho Cucamonga man in his 20s, was found shortly after 1800 PST.