A strong upper level trough moved across Southern California December 27th through 29th of 2020, bringing areas of heavy rain and heavy mountain snowfall. Some communities saw flooded streets and snow covered roads, leading to travel disruptions and road closures.

Heavy Snow in RIVERSIDE COUNTY MOUNTAINS, CALIFORNIA
From 28-DEC-20 00:00:00 to 30-DEC-20 00:00:00 (PST-8)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy snow fell on Riverside County Mountains.

Flash Flood in ORANGE, CALIFORNIA
From 29-DEC-20 17:34:00 to 29-DEC-20 19:00:00 (PST-8)
Location: DYER
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public reports a swift water rescue in the channel near the intersection of Raitt Street and Edinger Avenue in Santa Ana. Reports of 2 people swept away in the channel.

Flood in ORANGE, CALIFORNIA
From 28-DEC-20 18:29:00 to 28-DEC-20 21:00:00 (PST-8)
Location: PERALTA HILLS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Standing water of approximately 2.5 feet in lanes at Route 55 and Route 91 connector reported by CalTrans.

Flood in RIVERSIDE, CALIFORNIA
From 28-DEC-20 17:40:00 to 28-DEC-20 21:00:00 (PST-8)
Location: CRESTMORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

CalTrans reports flooding and standing water on Route 60 westbound at Rubidoux interchange.

Flood in RIVERSIDE, CALIFORNIA
From 28-DEC-20 18:00:00 to 28-DEC-20 23:00:00 (PST-8)
Location: TEMECULA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

CalTrans reports Interstate 15 South at Temecula Parkway/Highway 79 with mud and water in lanes 1 and 2. The area measured 1.5 to 1.9 inch rainfall in 24 hours.

Flood in SAN DIEGO, CALIFORNIA
From 28-DEC-20 17:00:00 to 28-DEC-20 22:00:00 (PST-8)
Location: TENT CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

CalTrans reports lanes flooded coming off the Coronado bridge onto the 5.

Flood in SAN DIEGO, CALIFORNIA
From 28-DEC-20 17:00:00 to 28-DEC-20 23:00:00 (PST-8)
Location: UNIVERSITY HGTS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding reported on road where lanes merge on I-805 northbound and El Cajon Boulevard interchange.

Thunderstorm Wind in SAN DIEGO, CALIFORNIA
From 28-DEC-20 19:00:00 to 28-DEC-20 20:00:00 (PST-8)
Location: LINCOLN ACRES
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

NBC 7 media reports large palm tree top snapped off and damage to the roof of an Amazon warehouse. A line of thunderstorms moved through this area 7 to 8 pm Monday the 28th. Heavy rain and wind microburst likely caused damage. photos provided on nbc7.

High Wind in SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS - THE INLAND EMPIRE, CALIFORNIA
From 31-DEC-20 15:30:00 to 31-DEC-20 16:00:00 (PST-8)
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

SoCal Edison Site Thunder Ridge (SE851) reports wind gust of 63 MPH on December 31st at 3:30 PM in the Pedley Hills above Jurupa Valley.

Heavy Snow in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 27-DEC-20 20:00:00 to 29-DEC-20 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

San Bernardino County Public works reports a road closure of Brookside Road in Crestline due to downed trees. with heavy snow of 17 inches reported around 5,000 feet. Heavy snow of 15 inches also reported by a trained spotter in Lake Arrowhead and at SNow Valley ski resort of close to 20 inches in total.

Winter Storm in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 28-DEC-20 16:00:00 to 29-DEC-20 00:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

CalTrans reports lane closures along Interstate 15 through the Cajon Pass due to snowfall down to 3,500 feet. The area experienced major traffic delays and multiple vehicle spinouts.