A low pressure system brought wind, snow, heavy rain, and some debris flows to Southern California from November 29th through 30th. Strong wind associated with the frontal boundary made its way through Southern California on the 29th, with heavy rain behind it. These rains resulted in numerous flash floods and debris flows, closing roadways and impacting traffic. A few inches of snow fell in the San Bernardino Mountains on November 30th. Fawnskin reported 3 inches, Green Valley Lake reported 4 inches, and Big Bear Resort reported 4-8 inches.

Flash Flood in RIVERSIDE, CALIFORNIA
From 29-NOV-18 09:00:00 to 29-NOV-18 12:00:00 (PST-8)
Location: BLY
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Media reported highway 60 (Pomona Ave.) at Etiwanda Ave. was flooded due to heavy rain with accidents reported in the area.

Flash Flood in RIVERSIDE, CALIFORNIA
From 29-NOV-18 10:00:00 to 29-NOV-18 13:00:00 (PST-8)
Location: HIGH GROVE
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Law Enforcement

California Highway Patrol reported a vehicle stuck in approximately 1 foot of standing water along Highway 210. No injuries were reported.

High Wind in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 29-NOV-18 08:00:00 to 29-NOV-18 09:00:00 (PST-8)
Magnitude: 57.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Heaps Peak mesonet reported a peak wind gust of 57 knots between 0800 and 0900 PST on November 29th.

High Wind in SAN GORGONIO PASS NEAR BANNING, CALIFORNIA
From 29-NOV-18 07:00:00 to 29-NOV-18 08:00:00 (PST-8)
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Whitewater raws mesonet reported a peak wind gust of 52 knots between 0700 and 0800 PST on November 30th.

Heavy Rain in SAN BERNARDINO, CALIFORNIA
From 29-NOV-18 00:00:00 to 30-NOV-18 00:00:00 (PST-8)
Location: LYTLE CREEK
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet ssvc1 (8 mi nne of Rancho Cucamonga) reported a 24-hr rainfall total of 3.38 inches.

Heavy Rain in SAN BERNARDINO, CALIFORNIA
From 29-NOV-18 00:00:00 to 30-NOV-18 00:00:00 (PST-8)
Location: CEDAR PINES
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

CoCoRaHS station ca-sr-63 in Crestline reported a 24-hr rainfall total of 3.6 inches.

Debris Flow in RIVERSIDE, CALIFORNIA
From 29-NOV-18 10:00:00 to 29-NOV-18 15:00:00 (PST-8)
Location: DURANT
Flood cause: Heavy Rain / Burn Area
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter reported a significant gray water flow in Horsethief Canyon within the canyon banks. No injuries or damages were reported.

Debris Flow in ORANGE, CALIFORNIA
From 29-NOV-18 11:00:00 to 29-NOV-18 15:00:00 (PST-8)
Location: TRABUCO CANYON
Flood cause: Heavy Rain / Burn Area
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Media reported major debris flow in Trabuco Canyon. The debris flow appeared to be mainly comprised of very little water and mostly mud/rocks.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 29-NOV-18 10:30:00 to 29-NOV-18 14:00:00 (PST-8)
Location: VERDEMONTE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Department of Highways reported a road closure due to flooding on Verdemont and Cajon Blvd.

Debris Flow in RIVERSIDE, CALIFORNIA
From 29-NOV-18 11:00:00 to 29-NOV-18 14:00:00 (PST-8)
Location: ARCILLA
Flood cause: Heavy Rain / Burn Area
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

CalFire reported water and debris from Coldwater Canyon flowing over into Glen Ivy Road.

Heavy Rain in ORANGE, CALIFORNIA
From 29-NOV-18 00:00:00 to 30-NOV-18 00:00:00 (PST-8)
Location: TRABUCO CANYON
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Santiago Peak 2 mesonet reported a 24-hr rain total of 3.24 inches.

Debris Flow in SAN BERNARDINO, CALIFORNIA
From 29-NOV-18 11:00:00 to 29-NOV-18 15:00:00 (PST-8)
Location: FOREST FALLS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

CalTrans reported an emergency closure of SR-38 at Valley of the Falls Drive due to a debris flow.

Debris Flow in RIVERSIDE, CALIFORNIA
From 29-NOV-18 11:00:00 to 29-NOV-18 15:00:00 (PST-8)
Location: ARCILLA
Flood cause: Heavy Rain / Burn Area
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Riverside County Emergency Management reported water and rocks in the road near Temescal Canyon.

High Wind in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 29-NOV-18 09:00:00 to 29-NOV-18 10:00:00 (PST-8)
Magnitude: 55.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Burns Canyon mesonet reported a peak wind gust of 54 knots between 0900 and 1000 PST on November 29th.

High Wind in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 29-NOV-18 01:00:00 to 29-NOV-18 02:00:00 (PST-8)
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mormon Rock Mesonet reported a peak wind gust of 61 knots between 0100 and 0200 PST on November 29th.