Monsoonal thunderstorm activity occurred across Southern California from July 22 to July 29, with a major easterly wave producing widespread convection on July 25 and 26. Numerous reports of heavy rain leading to flash flooding and debris flows were received as well as reports of lightning, hail and dust storm.

Heavy Rain in SAN BERNARDINO, CALIFORNIA
From 22-JUL-21 00:00:00 to 29-JUL-21 00:00:00 (PST-8)
Location: YUCAIPA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Table of rainfall amounts over 7 days across the El Dorado and Apple Burn Scars. Three locations received over 1 inch in 7 days.

Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 02:00:00 to 26-JUL-21 05:00:00 (PST-8)
Location: THOUSAND PALMS
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 1.00K
Reported by: Broadcast Media

Desert Sun photo of mud and water covering Vista del Sol and Ramon Road in Thousand Palms. This area received heavy rain 3 to 6 am. Nearby Cathedral City site reported 0.52 inches in 1 hour.

Flash Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 03:06:00 to 26-JUL-21 03:06:00 (PST-8)
Location: MECCA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

One vehicle swept off the roadway on box canyon road with 10 to 12 other vehicles potentially stranded.

Flash Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 05:07:00 to 26-JUL-21 05:07:00 (PST-8)
Location: BERMUDA DUNES ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding on Varner road near Bermuda Dunes.

Heavy Rain in SAN DIEGO, CALIFORNIA
From 22-JUL-21 14:05:00 to 22-JUL-21 14:05:00 (PST-8)
Location: DUBBERS SPUR
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy rain of 0.5 inch. Spotter report of a heavy downpour near Jacumba for 10-15 minutes with 2-3 inches of water on the patio, and about 2 feet of water on sections of the dirt road leading to his home.

Heavy Rain in SAN BERNARDINO, CALIFORNIA
From 26-JUL-21 01:20:00 to 26-JUL-21 02:10:00 (PST-8)
Location: LUCERNE VLY
Reported by: Mesonet

Between 1:20 and 2:10 am, station ar854 received 0.60 inch of rain.

Flood in RIVERSIDE, CALIFORNIA
From 25-JUL-21 19:30:00 to 25-JUL-21 19:30:00 (PST-8)
Location: MYOMA
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 1.00K
Reported by: Department of Highways

Flooding at intersection of Dillon Road and Thousand Palms Canyon Road with 200 foot section of roadway washed out.

Flash Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 02:30:00 to 26-JUL-21 02:30:00 (PST-8)
Location: MECCA
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 1.00K
Reported by: Emergency Manager

Radar estimated 2 to 2.5 inches of rainfall at the mouth of Box Canyon which caused flash flooding at the entrance of Box Canyon Road and along Painted Canyon Road. There were a couple vehicles involved with the flooding which caused a road closure. Located south of I-10 and north of Highway 111.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 26-JUL-21 04:00:00 to 26-JUL-21 04:00:00 (PST-8)
Location: CATHEDRAL CITY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Cathedral Canyon raws had 0.42 rainfall in 1 hour and 0.69 inches total.

Heavy Rain in SAN DIEGO, CALIFORNIA
From 26-JUL-21 04:00:00 to 26-JUL-21 04:00:00 (PST-8)
Location: PALOMAR MTN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Palomar Mountain raws had 0.49 inches in 1 hour. 0.96 total so far.

Heavy Rain in SAN BERNARDINO, CALIFORNIA
From 26-JUL-21 03:00:00 to 26-JUL-21 04:00:00 (PST-8)
Location: COLTON ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station au239 Rialto 1. Between 2 and 3 am received 0.35 inches.

Flash Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 04:11:00 to 26-JUL-21 04:11:00 (PST-8)
Location: PALM DESERT
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 1.00K
Reported by: Department of Highways

Caltrans reports boulders in the roadway near Vista Point on SR 74.

Flash Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 04:30:00 to 26-JUL-21 04:30:00 (PST-8)
Location: BERMUDA DUNES ARPT
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 1.00K
Reported by: Emergency Manager

Damage and washed out section of concrete sidewalk as embankment gave way to flooding along Country Club Drive and Avenue 42. Water covered roadway on Jefferson Street. Photos shared by emergency management. Rain of 0.70 inch per hour observed.

Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 05:00:00 to 26-JUL-21 05:00:00 (PST-8)
Location: WHITE WATER
Flood cause: Heavy Rain
Property damage: 1.00K
Crop damage: 1.00K
Reported by: Emergency Manager

Riverside Emergency Management reported minor rock slide on Highway 111 at Windy Point. Rain gauges showed 0.50 in 30 minutes early that morning.

Heavy Rain in SAN DIEGO, CALIFORNIA
From 26-JUL-21 05:00:00 to 26-JUL-21 05:00:00 (PST-8)
Location: SAN LUIS REY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet weather station reported 0.89 inches of heavy rain.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 26-JUL-21 06:00:00 to 26-JUL-21 07:00:00 (PST-8)
Location: IDYLLWILD
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

San Jacinto raws received 1.44 inches of rain and 0.89 in 1 hour between 5 and 6 am.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 26-JUL-21 05:00:00 to 26-JUL-21 06:00:00 (PST-8)
Location: BONNIE BELL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Whitewater raws received 1.17 rainfall and 0.53 in 1 hour at 6 am.

Heavy Rain in SAN DIEGO, CALIFORNIA
From 26-JUL-21 06:00:00 to 26-JUL-21 06:00:00 (PST-8)
Location: PALOMAR MTN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHs station CA-SD-195 Valley Center 10.9 NE reported 1.54 inch of heavy rain.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 26-JUL-21 06:00:00 to 26-JUL-21 06:00:00 (PST-8)
Location: PALM DESERT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS station CA-RV-72 Palm Desert 2.1 ENE reported 0.81 inch of heavy rain.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 26-JUL-21 06:00:00 to 26-JUL-21 06:00:00 (PST-8)
Location: BONNIE BELL
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station WWAC1 Whitewater raws reported 1.23 inch of heavy rain.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 26-JUL-21 07:00:00 to 26-JUL-21 07:00:00 (PST-8)
Location: LA QUINTA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS station CA-RV-79 La Quinta 0.9 WNW reported 1.52 inch of heavy rain.

Flood in RIVERSIDE, CALIFORNIA
From 26-JUL-21 12:00:00 to 26-JUL-21 13:00:00 (PST-8)
Location: COACHELLA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Avenue 50 at Tyler Street closed at 1 pm due to water flowing over the road, per phone conversation with emergency manager. This is in the Whitewater Wash, a road designed to flood.