A cold unstable upper level low pressure system from the northwest brought widespread heavy rain, thunderstorms and mountain snow to southern California over the Thanksgiving holiday. One to three feet of snow fell above 5,500 feet in the mountains, impacting highways and passes. Big Bear and Mountain High reported 30 to 48 inches total. Highway 18 was closed through December 1st. Over 40 vehicles were stuck on Highway 74 and 371, while 20 vehicles were abandoned on Highway 38. There were 10 car accidents involving snow plows. Heavy rainfall of 1 to 3 inches fell at the coast and in the valleys. San Diego River reached 9.5 feet with flooding. Numerous roadways were flooded out, especially on November 28th when the heaviest rain fell. An RV park in La Mesa flooded out due to flash flooding. The San Diego River at Fashion Valley reached 9.5 feet. 2 separate episodes of severe thunderstorms occurred in San Diego County on Thanksgiving Day.

Heavy Snow in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 28-NOV-19 08:00:00 to 28-NOV-19 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy snow and gusty winds knocked down a tree and nearby power line in Crestline.

Debris Flow in ORANGE, CALIFORNIA
From 28-NOV-19 06:00:00 to 28-NOV-19 20:00:00 (PST-8)
Location: SAN JUAN HOT SPGS
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Motorist struck a 500 pound boulder on state highway 74 Ortega highway through the mountain pass. Heavy rainfall occurred the entire day which likely caused the debris flow and large boulder to be released.

Flash Flood in ORANGE, CALIFORNIA
From 28-NOV-19 09:00:00 to 28-NOV-19 17:00:00 (PST-8)
Location: HUNTINGTON BEACH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Pacific Coast Highway was closed from Seapoint Street to Warner Avenue due to flooding.

Flash Flood in SAN DIEGO, CALIFORNIA
From 28-NOV-19 10:00:00 to 28-NOV-19 14:00:00 (PST-8)
Location: LA MESA
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Numerous cars piled up in an RV park in La Mesa due to flash flooding.

Debris Flow in SAN DIEGO, CALIFORNIA
From 28-NOV-19 22:00:00 to 29-NOV-19 02:00:00 (PST-8)
Location: SAN YSIDRO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A large mudslide occurred on I-805 at the intersection of Hwy 905 in Otay Mesa.

Flash Flood in SAN DIEGO, CALIFORNIA
From 28-NOV-19 13:00:00 to 28-NOV-19 22:00:00 (PST-8)
Location: SORRENTO
Flood cause: Heavy Rain
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Department of Highways

Driver was rescued from his BMW after driving through 2 feet of water in Sorrento Valley. The vehicle was a total loss.

Flash Flood in SAN DIEGO, CALIFORNIA
From 28-NOV-19 11:00:00 to 28-NOV-19 15:00:00 (PST-8)
Location: NATIONAL CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Swift water rescue occurred in National City.

Heavy Snow in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 27-NOV-19 00:00:00 to 29-NOV-19 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The San Bernardino Mountains reported 1 to 3 feet of snow, with locally higher amounts on the highest peaks. Mt. Baldy recorded the highest amount of snow with 50 inches. Yucaipa Ridge (Forest Falls) recorded 41 inches of snow. Wrightwood recorded 34 inches and Green Valley Lake recorded 33 inches. Numerous cars slid out on Highway 18. On highway 38, over 20 vehicles were abandoned, making it nearly impossible for the road to be plowed.

Thunderstorm Wind in SAN DIEGO, CALIFORNIA
From 28-NOV-19 12:00:00 to 28-NOV-19 18:00:00 (PST-8)
Location: CARLSBAD
Magnitude: 41.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported straight line winds and roof damage in Carlsbad from thunderstorm wind outflow on November 28th.

Flash Flood in RIVERSIDE, CALIFORNIA
From 28-NOV-19 10:00:00 to 28-NOV-19 16:00:00 (PST-8)
Location: ORDWAY
Flood cause: Heavy Rain
Property damage: 760.00K
Crop damage: 0.00K
Reported by: Department of Highways

A sinkhole opened up on the shoulder of I-10 in Redlands due to heavy rain. Total cost to repair the large sinkhole was $760,000.

Heavy Snow in SAN DIEGO COUNTY MOUNTAINS, CALIFORNIA
From 27-NOV-19 00:00:00 to 29-NOV-19 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported 22 inches of storm total snow atop Palomar Mountain.

Heavy Snow in RIVERSIDE COUNTY MOUNTAINS, CALIFORNIA
From 27-NOV-19 00:00:00 to 29-NOV-19 23:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy snow was observed in the Riverside County Mountains, where up to 20 inches of snow fell. On Highway 74, 45 cars were stuck on Highway 74 and Highway 371 due to heavy snow.

Heavy Snow in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 27-NOV-19 20:00:00 to 28-NOV-19 08:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 2.00M
Reported by: Newspaper

Dozens of trees fell and snapped at the Wildlands Conservancy in Oak Glen due to heavy, wet snow. The area received around 18 to 24 inches of snow from the storm. The hundreds of downed trees resulted in closed roads and trails as well as cut off power to the area. An estimated 2 million dollars in damage occurred.