A potent trough of low pressure associated with a weak atmospheric river brought heavy mountain and snow and areas of flooding rains across Southern California from January 28th to 29th.

Heavy Snow in SAN DIEGO COUNTY MOUNTAINS, CALIFORNIA
From 28-JAN-21 00:00:00 to 30-JAN-21 00:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Widespread snowfall occurred, including 13 inches on Palomar Mountain.

High Wind in APPLE AND LUCERNE VALLEYS, CALIFORNIA
From 28-JAN-21 16:00:00 to 29-JAN-21 07:00:00 (PST-8)
Magnitude: 67.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Gusty winds occurred at the desert slopes of the region over 60 MPH. Burns Canyon reported a peak gust of 77 MPH.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 28-JAN-21 00:00:00 to 30-JAN-21 00:00:00 (PST-8)
Location: SAN JACINTO
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reports 1.34 inches of rain.

Heavy Rain in RIVERSIDE, CALIFORNIA
From 28-JAN-21 00:00:00 to 30-JAN-21 00:00:00 (PST-8)
Location: TEMECULA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reports 1.6 inches of heavy rainfall.

Flood in RIVERSIDE, CALIFORNIA
From 29-JAN-21 06:00:00 to 29-JAN-21 09:00:00 (PST-8)
Location: PERRIS
Flood cause: Heavy Rain
Property damage: 1000.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Vehicle stuck in water on San Jacinto and Murrieta Rd in Perris., where a water rescue was conducted.

Heavy Rain in ORANGE, CALIFORNIA
From 28-JAN-21 00:00:00 to 30-JAN-21 00:00:00 (PST-8)
Location: GALIVAN
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Observer reports 1.1 inches of rainfall.

Heavy Rain in ORANGE, CALIFORNIA
From 28-JAN-21 00:00:00 to 30-JAN-21 00:00:00 (PST-8)
Location: COLONIA INDEPENDCIA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Observer reports 1.21 inches of rainfall.

Flood in SAN DIEGO, CALIFORNIA
From 29-JAN-21 10:00:00 to 29-JAN-21 18:00:00 (PST-8)
Location: LAKE SAN MARCOS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Via Vera Cruz closed between Discovery Street and W. San Marcos Blvd through riverbed.

Flood in SAN DIEGO, CALIFORNIA
From 29-JAN-21 06:00:00 to 29-JAN-21 10:00:00 (PST-8)
Location: DEL DIOS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Escondido Creek flowing causing, Country Club Drive to close near Harmony Grove Road.

Flood in SAN DIEGO, CALIFORNIA
From 29-JAN-21 15:00:00 to 29-JAN-21 20:00:00 (PST-8)
Location: LEMON GROVE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Large pool of water in lane 1 with vehicles hydroplaning. 0.25 to 0.30 inches past 2 hours and thunderstorms passage. Occurred on the north connector of 125 to highway 94.

Flood in SAN DIEGO, CALIFORNIA
From 28-JAN-21 20:00:00 to 30-JAN-21 06:00:00 (PST-8)
Location: OTAY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

I-805 flooding in far right lane just north of main street.

Flash Flood in SAN DIEGO, CALIFORNIA
From 29-JAN-21 15:30:00 to 29-JAN-21 18:30:00 (PST-8)
Location: SAN YSIDRO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

San Diego fire department and rescue and U.S. Border Patrol report 8 people trapped in a flooding storm drain between Otay Mesa and San Ysidro. 7 people were helped to safety with one fatality.

Debris Flow in ORANGE, CALIFORNIA
From 28-JAN-21 20:00:00 to 29-JAN-21 07:00:00 (PST-8)
Location: SILVERADO
Flood cause: Heavy Rain / Burn Area
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Reports of large amounts of mud and debris covering roadways and damaging homes in Silverado Canyon area. The area saw around 1.5 inches of rainfall from this system.

Heavy Snow in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 28-JAN-21 00:00:00 to 30-JAN-21 00:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The storm produced close to one foot of snowfall as measured by trained spotters, as well as high-elevation ski resorts reporting over 2 feet.

Heavy Snow in RIVERSIDE COUNTY MOUNTAINS, CALIFORNIA
From 28-JAN-21 00:00:00 to 30-JAN-21 00:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

CalTrans reports various spots of near one foot of storm total snowfall.