These days were a continuation of the deep monsoonal flow that persisted over the area through much of the month. Thunderstorms developed each afternoon over the mountains, deserts and northern inland valleys, and quickly diminished by sunset with areas of rural, urban and flash flooding. Flooding activity on the 11th was focused around Big Bear and Victorville in San Bernardino County, as well as Campo in San Diego County. Thunderstorm activity also developed along the Elsinore Convergence Zone in eastern Riverside County. Thunderstorms in this area became severe and produced a couple damaging microbursts along with the small hail and heavy rain. Similar storms in the Elsinore area on the 12th produced a landspout and another damaging microburst. Significant flooding was also observed in the Forest Falls area on that day. Mostly minor urban flooding was observed in the upper deserts and Forest Falls again on the 13th.

Thunderstorm Wind in RIVERSIDE, CALIFORNIA
From 11-AUG-12 14:00:00 to 11-AUG-12 16:00:00 (PST-8)
Location: LAKE ELSINORE
Magnitude: 76.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The Temescal RAWS near Lake Elsinore measured a wind gust of 88 mph between 1432 and 1532 PST, associated with a nearby warned thunderstorm.
Winds were estimated at 60-65 mph from a microburst around 20 yards wide that caused damage in a residential neighborhood in northeast Temecula. It descended in a backyard and blew down the fences on the north and south ends of the yard. The fences were blown outward from the yard, indicative of a downward and outward thrust of winds.
Several large branches were broken and a few small trees downed in Trilogy at the Glen Ivy Resort and Spa. Estimated winds from the damage was 60 mph as determined by an NWS employee.

Tornado in RIVERSIDE, CALIFORNIA
From 12-AUG-12 14:30:00 to 12-AUG-12 15:45:00 (PST-8)
Location: PERRIS
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A land spout tornado was associated with and southwest of the parent (non-supercell) thunderstorm that was over Nuevo, on the east side of Perris. The land spout appeared to be over the fields just east of or near Interstate 215. Separate wind damage from the parent thunderstorm was observed to the northeast over Nuevo on Menifee Road.
There was no apparent damage from the land spout itself. A spotter also sent in video of the land spout.

Thunderstorm Wind in RIVERSIDE, CALIFORNIA
From 12-AUG-12 14:30:00 to 12-AUG-12 16:00:00 (PST-8)
Location: NUEVO
Magnitude: 52.00 EG
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Newspaper

A severe thunderstorm caused significant straight-line wind damage from a wet microburst on the east side of Perris on Nuevo Road near Menifee Road. Several power poles were snapped completely and fell over like dominoes. Several vehicles were trapped in between the downed poles, though no one was injured. Law enforcement was called in to close off several roads in the area. The wind also tore up some roofing on a few homes in the area. This damage was likely caused by winds from a microburst and not the nearby landspout, though both were the result of the same parent thunderstorm cell.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 11-AUG-12 10:30:00 to 11-AUG-12 13:30:00 (PST-8)
Location: BALDWIN LAKE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Very heavy rainfall in the Big Bear area began around 1045 PST, resulting in minor street flooding in Big Bear City, as well as flash flooding along Highway 38 at mile marker 19. Cal Trans and CHP closed Highway 38 at this point due to a stream of water rushing down the road with embedded boulders.
A nearby spotter measured rainfall of 0.16 inches in 10 minutes and 0.95 inches in one hour, along with pea sized hail.

Lightning in SAN DIEGO, CALIFORNIA
From 11-AUG-12 12:30:00 to 11-AUG-12 13:30:00 (PST-8)
Location: CAMPO
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy thunderstorm moving north toward Highway 94 and Interstate 8 with frequent lightning. Lightning hit the spotter's well in her yard.
Heavy rain also caused minor flooding on Buckman Springs Road.

Thunderstorm Wind in SAN DIEGO, CALIFORNIA
From 12-AUG-12 13:00:00 to 12-AUG-12 14:00:00 (PST-8)
Location: WARNER SPGS
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The SDGE East Warners sensor recorded a 58 mph gust during a thunderstorm. A spotter also reported marble to penny sized hail (0.75 inch) 2 to 3 miles east of the San Felipe Road turnoff of SR 79.

Flash Flood in SAN DIEGO, CALIFORNIA
From 12-AUG-12 13:00:00 to 12-AUG-12 14:00:00 (PST-8)
Location: SAN FELIPE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

CHP closed San Felipe Road (S2) between mile markers 2 and 3 due to mud and water that is 3 feet deep.

Thunderstorm Wind in RIVERSIDE, CALIFORNIA
From 12-AUG-12 15:15:00 to 12-AUG-12 16:30:00 (PST-8)
Location: PERRIS
Magnitude: 48.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

On the west side of Perris, on Olive and Ellis Streets and just north of Highway 74, several small and large tree limbs down. Two power poles were broken by wind but remained leaning on Ellis Street just north of Highway 74. One rural street in that area was closed due to water about 12 inches deep. Estimated wind gusts were 50-55 mph for just this area. This damage was determined to be associated with a wet microburst from the severe storm in the area.

Funnel Cloud in RIVERSIDE, CALIFORNIA
From 12-AUG-12 15:15:00 to 12-AUG-12 15:45:00 (PST-8)
Location: PERRIS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A funnel cloud was observed just south of Perris from approximately 1525 to 1535 PST on the 12th. The funnel was observed by a spotter located near Albert Hill, north of Lake Elsinore as the severe thunderstorm moved east along Highway 74. The funnel was not determined to be associated with the landspout east of Perris.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 12-AUG-12 13:00:00 to 12-AUG-12 14:00:00 (PST-8)
Location: FOREST FALLS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter heard on a police scanner that a 3-foot wall of water  came down near forest Falls and Angelus Oaks. Police evacuated people that were down at the bottom of the Santa Ana River/Mill Creek. The flooding was estimated to have occurred between 1330 and 1400 PST.

Flood in SAN BERNARDINO, CALIFORNIA
From 11-AUG-12 13:00:00 to 11-AUG-12 14:00:00 (PST-8)
Location: ADELANTO HANSEN ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Flooding observed on HIghway 395 as well as along Highway 18 and Phelan Road. Water was flowing on streets on both sides. Up to 4 inches of water was flowing at the intersection of Highway 395 and Mojave Road, with up to 8 inches of standing water at dips in the roads.