A strong atmospheric river produced widespread moderate to heavy rainfall across Southern California March 14-15. Rain amounts of 1 to 3 inches were observed across the coastal basin, with heavier amounts up to 4 inches reported in the mountains. Rain fell on an extremely deep snowpack in the mountains, resulting in flooding. Flooding also occurred across the coast and valleys, where several debris flows occurred.

Debris Flow in ORANGE, CALIFORNIA
From 15-MAR-23 08:18:00 to 15-MAR-23 08:18:00 (PST-8)
Location: SAN CLEMENTE
Flood cause: Heavy Rain
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

A significant landslide occurred following heavy rain in San Clemente on the 1500 block of Buena Vista the morning of March 15. All buildings were immediately evacuated, with no injuries reported. At least four apartment buildings had been red-tagged by the afternoon (deemed too dangerous to enter).

Flood in RIVERSIDE, CALIFORNIA
From 15-MAR-23 08:19:00 to 15-MAR-23 08:19:00 (PST-8)
Location: SUN CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Firefighters responded to a vehicle submerged in 1 foot of water at Matthews Road and Palomar Road. Four occupants were rescued from the vehicle.

Debris Flow in SAN DIEGO, CALIFORNIA
From 15-MAR-23 12:15:00 to 15-MAR-23 12:15:00 (PST-8)
Location: JULIAN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Department of Highways announced the closure of Highway 78 between Wynola Road and the Banner Store due to a mudslide in the eastbound lanes.

Flood in SAN BERNARDINO, CALIFORNIA
From 15-MAR-23 08:00:00 to 15-MAR-23 08:00:00 (PST-8)
Location: PHELAN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding reported at Amarillo and Buckwheat Road, with rain of 0.50 inch reported.

Flood in RIVERSIDE, CALIFORNIA
From 15-MAR-23 09:00:00 to 15-MAR-23 09:00:00 (PST-8)
Location: PALM SPGS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Broadcast media reports Gene Autry Trail, North Indian Canyon Drive and Araby Drive in the Coachella Valley closed due to flooding.

Strong Wind in SAN DIEGO COUNTY COASTAL AREAS, CALIFORNIA
From 15-MAR-23 05:00:00 to 15-MAR-23 05:30:00 (PST-8)
Magnitude: 30.00 MG
Reported by: Broadcast Media

Gusty winds occurred early in the morning on March 15, and numerous large trees were reported downed, including one near Mt Soledad and one along Highway 163.

Flash Flood in RIVERSIDE, CALIFORNIA
From 15-MAR-23 15:00:00 to 15-MAR-23 17:00:00 (PST-8)
Location: HINDA
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: County Official

Caltrans reported 2 feet of water (photos included) on fast lane of state highway 60 at Jack Rabbit Trail, causing lane closures.  Between 400 and 418 pm local.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 14-MAR-23 20:00:00 to 15-MAR-23 08:00:00 (PST-8)
Location: CHINO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Very heavy rainfall occurred across the Inland Empire from the evening on March 14 through the morning on March 15. Rainfall of 2.00-3.50 fell, with local amounts up to 4 inches closer to the San Bernardino County Mountains. Flash flooding was reported early on the morning of March 15; firefighters responded to a vehicle in swift moving water, and the rescue was successful. Also, Grove Ave between Merrill Ave, Chino and Riverside Ave in Ontario saw 2 to 4 inches of running water covering the entire roadway. Kimball Ave in Chino between Quality Way and Euclid Ave were flooded with 2 to 4 inches of standing water.

Flood in RIVERSIDE, CALIFORNIA
From 15-MAR-23 16:12:00 to 15-MAR-23 16:32:00 (PST-8)
Location: CALIMESA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Heavy rainfall fell across eastern portions of the Inland Empire the evening of March 14 through the afternoon on March 15. Rainfall of 1.00-2.25 was reported, and multiple reports of flooding were received via the Department of Highways: Cherry Valley Blvd at Roberts Road was flooded, as well as three lanes of Highway 60.

Flood in ORANGE, CALIFORNIA
From 15-MAR-23 01:18:00 to 15-MAR-23 01:18:00 (PST-8)
Location: SANTA ANA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Very heavy rainfall occurred across inland Orange County from the evening on March 14 through the morning on March 15. Rainfall of 1.50-2.50 fell. An MPing report of street and road flooding resulting in road closures and stranded vehicles was reported near Santa Ana early in the morning on March 15.

Debris Flow in RIVERSIDE, CALIFORNIA
From 15-MAR-23 06:39:00 to 15-MAR-23 06:39:00 (PST-8)
Location: SAN JUAN HOT SPGS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Department of Highways reported at leas three big boulders blocking SR-74.

Flash Flood in RIVERSIDE, CALIFORNIA
From 15-MAR-23 08:19:00 to 15-MAR-23 08:19:00 (PST-8)
Location: SUN CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Swiftwater rescue conducted by firefighters at Matthews Rd and Palomar Rd, with a vehicle submerged in one foot of water, with four occupants rescued.

Flood in SAN DIEGO, CALIFORNIA
From 15-MAR-23 05:30:00 to 15-MAR-23 09:00:00 (PST-8)
Location: RAINBOW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Flooding occurred early in the morning on March 15 following very heavy rainfall over the previous 24 hours, with precipitation amounts of 2.5-3.5 inches. Huffstalter St between 5th and 2nd St was closed due to flooding, as well as Pala Temecula Road.

Debris Flow in SAN DIEGO, CALIFORNIA
From 15-MAR-23 05:38:00 to 15-MAR-23 05:38:00 (PST-8)
Location: RAINBOW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Department of Highways reported a rockslide on the southbound lanes of SR-76 early in the morning on March 15. Rainfall of 2.50-3.50 inches occurred with the event.

Debris Flow in SAN DIEGO, CALIFORNIA
From 15-MAR-23 06:27:00 to 15-MAR-23 06:27:00 (PST-8)
Location: RAMONA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Department of Highways reported a large boulder blocking the southbound lanes of Highway 78.

Flood in SAN DIEGO, CALIFORNIA
From 15-MAR-23 03:00:00 to 15-MAR-23 08:00:00 (PST-8)
Location: CARLSBAD
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Significant flooding was reported early in the morning on March 15 by the Department of Highways.
SR-78 near Carlsbad initially saw flooding around 3 AM on March 15, with flooding starting on the on-ramp, eventually expanding onto the eastbound lanes of SR-78, and into the westbound lanes nearly two hours later. A hard closure was announced around 5:30 AM for the eastbound lanes, with the westbound lanes closing around 7 AM.
Flooding was reported on Discovery St near San Pablo Ct, with a closure reported on Discovery St around 8 AM.
La Costa Ave was flooded at El Camino Real.
Widespread rainfall of 2.00-3.00 was reported in the 24 hours surrounding the flooding in coastal north county.

Debris Flow in SAN BERNARDINO, CALIFORNIA
From 15-MAR-23 05:00:00 to 15-MAR-23 14:00:00 (PST-8)
Location: CRESTLINE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Mudslides, rockslides and debris flows were reported across western portions of the San Bernardino County Mountains on March 15 as widespread heavy rainfall of 1.00-3.50+ inches occurred. Rockslides occurred along the upper passing lanes on SR-330 near Running Springs; mud and rocks blocked the upbound lanes of Highway 18 at Old Waterman Canyon Road near Crestline; rocks were reported across the road on SR-18 near Crestline, and a vehicle reportedly hit the rocks.

Flood in SAN BERNARDINO, CALIFORNIA
From 15-MAR-23 06:20:00 to 15-MAR-23 06:20:00 (PST-8)
Location: FOREST FALLS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Department of Highways reported a rock slide on both the upbound and downbound lanes on SR-38.

Flood in SAN BERNARDINO, CALIFORNIA
From 15-MAR-23 06:00:00 to 15-MAR-23 15:45:00 (PST-8)
Location: BIG BEAR CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Flooding occurred near Big Bear City on March 15 following heavy rainfall of 0.50-1.50, with reports of 2.00-3.00+ inches nearby. Heavy rain combined with snow melt to lead to flooding in the San Bernardino County Mountains. The Department of Highways reported the closure of Gildart Drive and Division Drive; Irvine Way and Barrett Way were flooded; the riverbed broke through and resulted in flooding at SR-38, with 3 inches of standing water reported between Baldwin and State Lane.