An upper-level low from Baja cut underneath a large area of seasonably strong high pressure aloft, tapping into lingering monsoonal moisture to produce showers and thunderstorms over the mountains and deserts, as well as a few along the coastal areas, with heavy rain at times. The activity on the 2nd consisted of elevated thunderstorms with lightning along the coast during the morning and a few thunderstorms over the San Bernardino County mountains. Rain and rapid cooling in one of these storms resulted in several bicyclists being treated for hypothermia during the Tour de Big Bear race. This elevated convection became intense and transitioned into numerous strong thunderstorms on the 3rd, focusing more on the mountains and deserts and closing several roadways due to flooding. Rainfall of 2 to 4 inches occurred in less than 3 hours across steep terrain in the San Bernardino County mountains. The hardest hit areas were Mt Baldy, Forest Falls and Oak Glen where numerous debris flows occurred causing road damage and closures. Incident Command Posts were set up at both Mt Baldy and Valley of the Falls. A weather station in Mt Baldy reported 4 inches of rain in less than 2 hours. Swift water rescues were performed in Mt Baldy along the LA County line. There was also a large area of 1 to 2.5 inches of rain in low-lying areas and deserts, including 2.73 inches in one hour at the Borrego ALERT gage. The Fish Creek RAWS in the San Diego County desert recorded 2.77 inches of rain in one hour, resulting in moderate flooding and the subsequent closure of Fish Creek Road through August 8th. Heavy rain west of the mountains produced flash flooding in Redlands and Ramona. A large sink hole developed in Redland due to heavy rainfall. San Bernardino County was the hardest hit with flash flooding, with 25 homes damaged and approximately $11 million in damage county-wide for this event. Full storm surveys were done from Mill Creek near Forest Falls, to Oak Glen, to Lytle Creek and through out Mt Baldy on August 4th.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 03-AUG-14 19:00:00 to 03-AUG-14 20:00:00 (PST-8)
Location: ADELANTO HLNDALE ARP
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a flooded wash with multiple cars stuck in the area.  4 inches of rain recorded in gauge within 2 hours on the steep slope of big Mt Baldy. A hiker parked their car in the small town of Mt Baldy and hiked to the top. Hail and lightning caused them to go back down the mountain early. They used the dry creek to go back
down and were swept away in a flash flood over 10 feet, per NWS Storm Survey of high water marks on trees. The hiker's car was found the next
day during the NWS Storm Survey. The car was destroyed and the person drowned somewhere along the middle or bottom of the creek, just on the San Bernardino County side. LA County Fire department led the search and rescue. Since Mt Baldy
town, where the car was parked, is in San Bernardino County they ended up having a unified command with Los Angeles County, San Bernardino Fire, and Town of
Mt Baldy.  At least 2 vehicles were towed out of the creek. We were told at the survey that the cars were on the Los Angeles County side of the mountain but washed downstream, and across the San Bernardino County side of the mountain, where the one fatality of a 48-yr old man from El Segundo, occurred.

Flash Flood in SAN DIEGO, CALIFORNIA
From 01-AUG-14 12:30:00 to 01-AUG-14 14:00:00 (PST-8)
Location: CLOVER FLAT
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a rock slide on Sunrise Highway (S1) partially blocking northbound lane. Just south of that location, a spotter reported water on roadways up to 6 inches on parts of Oak Drive...Sage Drive...Lake Shore Drive...Cyprus Drive...and Bass Road, near Lake Morena. Standing water was up to the front door of one home and the garage door of another.

Flash Flood in SAN DIEGO, CALIFORNIA
From 01-AUG-14 14:30:00 to 01-AUG-14 15:00:00 (PST-8)
Location: VALLEY CENTER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported water over the highway near the intersection of Highway 79 and Chihuahua Valley Road with traffic stopped in both directions. A spotter also reported the roadway washed out at the same location.

Flash Flood in RIVERSIDE, CALIFORNIA
From 02-AUG-14 11:30:00 to 02-AUG-14 12:00:00 (PST-8)
Location: CABAZON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reports roadway flooding on Danbury Street in Cabazon. Flood water, rocks, mud, and debris flowing down the street. The roadway is impassable due to boulders and mud blocking the street.

Flash Flood in RIVERSIDE, CALIFORNIA
From 03-AUG-14 13:00:00 to 03-AUG-14 14:00:00 (PST-8)
Location: CATHEDRAL CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Dinah Shore Drive between Date Palm Drive and Cathedral Canyon Drive was flooded...with at least one car abandoned.

Flash Flood in RIVERSIDE, CALIFORNIA
From 03-AUG-14 13:00:00 to 03-AUG-14 14:00:00 (PST-8)
Location: MECCA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway washed out near the intersection of Box Canyon Road / 66th ave. Road closure required.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 03-AUG-14 16:30:00 to 03-AUG-14 20:30:00 (PST-8)
Location: SAN BERNARDINO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported the east and west bound lanes of Interstate 210 were flooded. CHP also reported Marshall Boulevard flooded between Sterling and Arden Avenues, with vehicles stuck in the roadway. A couple hours later, the California Department of Forestry reported significant flooding in the city of Highland in the area of Baseline Road. Everyone was advised to shelter in place while they check for people stuck in water/mud.

Flood in SAN BERNARDINO, CALIFORNIA
From 03-AUG-14 17:00:00 to 03-AUG-14 17:30:00 (PST-8)
Location: COLTON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a vehicle almost under water at the intersection of Reche Canyon Road and Prado Lane.

Flash Flood in RIVERSIDE, CALIFORNIA
From 03-AUG-14 13:30:00 to 03-AUG-14 19:00:00 (PST-8)
Location: PEDLEY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: River/Stream Gage

USGS gage in the Perris Valley storm drain at Nuevo Road showed a spike from 8.68 ft to 14.94 ft. by 2100 PST. The initial rise of 3 ft. occurred in less than 30 minutes. Flash flood duration was 2 hours 15 minutes. Another USGS gage on the Santa Ana River at Arlington jumped from 5.66 ft to 10.31 ft over 2 hours.

Debris Flow in SAN DIEGO, CALIFORNIA
From 03-AUG-14 09:30:00 to 03-AUG-14 10:30:00 (PST-8)
Location: CAMPO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported mud/dirt/rock on Campo Road/State Route 94 just west of Forest Gate Road due to heavy rainfall.

Flash Flood in SAN DIEGO, CALIFORNIA
From 03-AUG-14 13:00:00 to 03-AUG-14 14:00:00 (PST-8)
Location: RAMONA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Water up to 2 feet deep reported at the intersection of Aqua and 4th Streets.

Flash Flood in SAN DIEGO, CALIFORNIA
From 03-AUG-14 14:30:00 to 03-AUG-14 15:30:00 (PST-8)
Location: BORREGO SPGS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a rock slide at the intersection of Yaqui Pass Road and Borrego Springs Road. The road needed to be shut down and plowed. Not far down Borrego Springs Road, a spotter reported flooding of streets...dry lakes and nearby areas flooded. CHP also reported Highway 78 being closed due to flooding at the intersection of Split Mountain Road, east of Borrego Springs.

Flash Flood in SAN DIEGO, CALIFORNIA
From 03-AUG-14 15:00:00 to 03-AUG-14 16:00:00 (PST-8)
Location: RANCHITA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reports Montezuma Valley Road being completely flooded with debris everywhere. The eastbound lane of that road completely collapsed. A spotter just south of this location reported heavy rain and debris flows on highway S-2.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 03-AUG-14 13:30:00 to 03-AUG-14 15:00:00 (PST-8)
Location: YUCAIPA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reports roadway flooded near the intersection of Oak Glen Road and Glen Road east of Yucaipa, with debris and water covering the road making it impassable. An NWS employee reported similar conditions along Oak Glen Road further west toward Yucaipa.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 03-AUG-14 14:30:00 to 03-AUG-14 16:00:00 (PST-8)
Location: MT BALDY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

California Highway Patrol reported a rock slide on Mount Baldy Road and requested the road be closed. This appears to have occurred just east of the LA county line. Damage from flooding and a propane tank rupture at the Mount Baldy visitor center. Many roads were washed out in the area. The direct cause and extent of the damage is unknown. The Mt. Baldy fire station alert gage reported a total of 4.4 inches of rain beginning at 1430 PST and ending at 1630 PST. The majority of that rain, 3.98 inches, fell in 60 minutes from 1445-1545 PST.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 03-AUG-14 18:30:00 to 03-AUG-14 19:30:00 (PST-8)
Location: LYTLE CREEK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP reported a side road of Lytle Creek Road was washed out due to heavy rainfall.

Flash Flood in RIVERSIDE, CALIFORNIA
From 02-AUG-14 10:00:00 to 02-AUG-14 11:00:00 (PST-8)
Location: PALM SPGS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Water, 4 to 6 inches deep in places, along Indian Canyon Drive near Palm Springs Station Road.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 03-AUG-14 14:00:00 to 03-AUG-14 15:00:00 (PST-8)
Location: FALLSVALE
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Cal OES San Bernardino reported flash flooding and debris flow in Mill Creek with people being evacuated from the creek basin. A spotter added that county fire was shutting down Valley of the Falls Drive at Highway 38. Shelter in place protocols were given by the county fire department. Multiple vehicles were reported in flooded wash and propane tanks were dislodged. Swift water rescues in progress. The area was closed to non-residents.