A large Pacific plume of moisture ahead of an advancing trough of low pressure brought heavy rain and periods of serious flooding for nearly a week. The plume of moisture responsible was a form of an Atmospheric River. The mountain areas, particularly the San Bernardino range, experienced record large rainfall totals and many areas of flash flooding, debris flows and mud slides. Most rivers in the county warning area reached flood stage. Other effects include numerous traffic collisions, roadway flooding and closures, swift water rescues, beach closures and millions of dollars in damage to homes, businesses and infrastructure. Along with numerous city and governor-declared States of Emergency, President Obama proclaimed a Federal disaster declaration for 10 counties in California, including all four counties comprising the SGX CWA.

Flood in SAN DIEGO, CALIFORNIA
From 21-DEC-10 13:30:00 to 23-DEC-10 08:00:00 (PST-8)
Location: GRANTVILLE
Flood cause: Heavy Rain
Property damage: 2.00M
Crop damage: 0.00K
Reported by: Official NWS Observations

The San Diego River at Fashion Valley has been above its flood stage of 11.3 feet since 1330 PST. A peak river stage of 14.01 feet was reported, making this a moderate flood event. The river flooding resulted in numerous closed roadways and portions of the Fashion Valley Mall parking facilities were under water. This river flooding also resulted in extensive flooding of the Qualcomm Stadium on Friars Road, including both the stadium itself and the surrounding parking lot. A total of about 1.5 million gallons of water had to be pumped out of that area, back into the river.
A flood channel overflowed, resulting in evacuations of 12 houses in Barrio Logan neighborhood in San Diego. Five people were evacuated from homes in Encanto due to stream flooding.

High Wind in APPLE AND LUCERNE VALLEYS, CALIFORNIA
From 20-DEC-10 07:00:00 to 20-DEC-10 20:00:00 (PST-8)
Magnitude: 61.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

High winds began at the Burns Canyon RAWS around 0700 PST and ended between 1900 PST and 2000 PST on the 20th. A peak wind gust of 70 MPH was measured between 1601 and 1700 PST.

Debris Flow in SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS - THE INLAND EMPIRE, CALIFORNIA
From 20-DEC-10 06:00:00 to 22-DEC-10 04:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Also shown on National News. Numerous mud and landslides in Loma Linda and Highland. Cars buried up to 2 feet deep and roads impassable due to diverted water and mud.

High Wind in APPLE AND LUCERNE VALLEYS, CALIFORNIA
From 19-DEC-10 08:00:00 to 19-DEC-10 09:00:00 (PST-8)
Magnitude: 54.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter in Hesperia measured a wind gust of 62 MPH at 0804 PST. Several fences were blown down in the local neighborhood.

Flash Flood in RIVERSIDE, CALIFORNIA
From 20-DEC-10 17:30:00 to 20-DEC-10 18:30:00 (PST-8)
Location: BLY
Flood cause: Heavy Rain
Property damage: 1.50K
Crop damage: 0.00K
Reported by: Law Enforcement

Flash flood occurred in Mira Loma around 1800 PST, requiring two different swift-water rescues of four people in total.

Flash Flood in SAN DIEGO, CALIFORNIA
From 21-DEC-10 05:00:00 to 21-DEC-10 06:00:00 (PST-8)
Location: CORONADO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Street flooding in Coronado. Both Northbound lanes on Orange Avenue have 3 to 4 inches of water on the roadway. There was 6 to 7 inches of water on 1st Street near the ferry landing as well.

Debris Flow in SAN BERNARDINO COUNTY MOUNTAINS, CALIFORNIA
From 20-DEC-10 10:00:00 to 20-DEC-10 12:00:00 (PST-8)
Property damage: 15.00M
Crop damage: 0.00K
Reported by: Newspaper

Highway 330, one of the main routes to Big Bear in the San Bernardino Mountains, collapsed near mile marker 35 on December 20. The force of the water coming down the mountain washed the hillside out from underneath the road itself, causing the collapse. Repairs to the road could take up to 2 years and $15 million.

Flash Flood in ORANGE, CALIFORNIA
From 22-DEC-10 05:00:00 to 22-DEC-10 17:00:00 (PST-8)
Location: EMERALD BAY
Flood cause: Heavy Rain
Property damage: 12.30M
Crop damage: 0.00K
Reported by: Newspaper

Heavy rain caused extensive flooding in downtown Laguna Beach with up to 4 feet of water on Broadway Street. Stranded motorists were rescued. The water also swept mud through homes, businesses and streets in the city. Approximately 184 businesses, homes and structures were damaged by the flooding. Sewer pumps were also damaged, resulting in the closure of about 12 miles of Orange County beaches, due to the pollution and waste entered into the storm runoff.

Flood in SAN BERNARDINO, CALIFORNIA
From 19-DEC-10 06:00:00 to 22-DEC-10 17:00:00 (PST-8)
Location: MT BALDY
Flood cause: Heavy Rain
Property damage: 97.00M
Crop damage: 0.00K
Reported by: Emergency Manager

San Bernardino County was the hardest hit county in California in terms of amount of damage due to the heavy rain at the end of December. County officials put the total damage amount (including public and private property of all types and labor to repair damage) at approximately $97 million. Both state and federal money will be available to help those affected.
Highway 395 at Highway 18 completely flooded with several stalled vehicles. Eastbound Highway 138 just west of LA County line has mud, debris and water across all lanes. Highway 18, west of Sheep Creek road is closed, as well as Koala Road between Rancho and El Mirage, due to flooding.

Flash Flood in RIVERSIDE, CALIFORNIA
From 22-DEC-10 04:50:00 to 22-DEC-10 06:00:00 (PST-8)
Location: QUAIL VLY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

A 39 year old Menifee woman was driving south on Goetz Road when the car was swept off the road by swift runoff from the Salt Creek, where it flows into Canyon Lake. She was found dead in her car at the bottom of the lake several hours later.

Flood in SAN BERNARDINO, CALIFORNIA
From 19-DEC-10 06:00:00 to 25-DEC-10 23:00:00 (PST-8)
Location: LOS SERRANOS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Numerous streets in the Chino area were flooded with several inches or more of water after nearly a week of intense rainfall. A 67 year old woman from Pasadena drove her car around a barricade near Chino on Christmas night. The water was deep enough that her car floated about 150 feet down the road, then sank in 10 feet of water. A 39 year old man, owner of a nearby business, jumped into the water and broke the car's sunroof to pull the woman out. He attempted CPR, but she later died at a local hospital.

Flash Flood in SAN BERNARDINO, CALIFORNIA
From 19-DEC-10 07:30:00 to 20-DEC-10 21:00:00 (PST-8)
Location: MT BALDY
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Sheep Creek near Wrightwood had a sudden surge in flow to 4 feet at approximately 0745 PST that carried large boulders, several feet in diameter, as well as logs several feet long and over a foot diameter.
Another surge of debris flow occurred at Sheep Creek around 1715 PST. The crossing of Lone Pine Road and Sheep Creek had debris 6 to 8 feet deep.
Flash Flooding around 1630 PST along Lytle Creek running over Glen Helen Parkway, near Interstate 15 northeast of Fontana. Water was within one foot of a levee. Another round of flash flooding occurred along Lytle Creek around 1800 PST. One motorist had to be rescued when trapped in his car in high water.
Around 1500 PST, 8 feet of mud and debris covered Valley of the Falls Drive near the fire station. At 1730 PST, the mud moved into homes along this road.

Flood in ORANGE, CALIFORNIA
From 19-DEC-10 06:00:00 to 22-DEC-10 17:00:00 (PST-8)
Location: SAN CLEMENTE
Flood cause: Heavy Rain
Property damage: 36.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Orange County officials estimate the total damages to public and private property at $36 million, due the 10+ of rain received by many areas. The city of Laguna Beach was certainly the hardest hit, making up approximately $12 million of the county's damages. Twelve miles of beaches in the county also had to be closed due to massive amounts of debris and pollution in storm runoff.