Flash Flooding and Debris Flow in California, January 18 to 24, 2017

A spotter in Moonridge reported 6-8 inches of new snow over a 7 hour period. Elsewhere, 3-5 inches was reported in Big Bear Lake and 3 inches at the end Mt. Baldy Rd., Arrowbear Lake, Green Valley Lake and Running Springs.

Rangers at the Long Valley Ranger Station reported 12 inches of new snow at 8,400 ft over a 13 hour period.

Very heavy snows were reported by San Bernardino County Public Works over a 24 hour period. Chain restrictions were widespread above 4,000 ft. Snow amounts ranged from a trace to 1 ft between 4,000 and 5,500 ft, while locations above 5,500 ft reported 1 to 2.5 ft of new snow. Some local totals included 31 inches in Green Valley Lake, 27 inches at Mt. Baldy, 20-27 inches in Big Bear Lake, 26 inches in Running Springs and Arrowbear Lake, 16 inches in Barton Flats, 15 inches in Angelus Oaks, and 11 inches in Wrightwood.

Rangers at the Long Valley Ranger Station reported 33 inches of new snow over a 24 hour period at 8,400 ft. Chain restrictions were required on local roadways.

The mesonet station in Burns Canyon reported wind gusts in excess of 70 mph between 1051 and 1351PST, with a peak of 99 mph between 1151 and 1251PST. Power lines were downed in Skyforest and Twin Peaks around 0930PST. A nearby mesonet station in Lake Arrowhead reported a peak gust of 50 mph between 0946 and 1001PST.

Numerous trees were downed along the Orange County coast by a combination of strong winds and saturated soils. Peak wind gusts during the period were in the 35-50 mph range.

Numerous trees were downed in the Orange County valleys by a combination of strong winds and saturated soils. Peak wind gusts at local mesonet stations during the period were in the 35-50 mph range.

Numerous trees were downed in the Inland Empire by a combination of strong winds and saturated soils. Peak wind gusts reported by area mesonet stations during the period were in the 35-45 mph range.

Strong winds impacted the coast over a 22 hour period. Strongest winds, with gusts in the 40-50 mph range occurred between 1300 and 1800PST on the 20th. Outside of this period, peak gusts were in the 25-35 mph range along the coast. The winds combined with saturated grounds to down hundreds of trees that fell on cars and structures. Four students were hospitalized when a large tree fell on them at Chula Vista Middle School.

CHP reported 6 flooded roadways in Paloma Valley with one vehicle briefly stranded.

A severe squall moved from Newport Beach to Santa Ana, downing multiple trees, knocking out power to 63 homes and causing minor roof damage.

Local mesonets reported wind gusts in the 25-40 mph range between 1300PST on the 20th and 0400PST on the 21st. Highest gusts occurred between 1400 and 1800PST. The winds combined with saturated soils to down numerous trees.

A severe squall produced 60-70 mph wind gusts over northern Camp Pendleton. A peak gust of 70 mph was measured at Mateo Ridge with an additional 64 mph gust recorded at Case Springs.

The Lake Matthews Raws station reported a 67 mph gust between 1316 and 1416 PST. In Temescal Valley a large tree was blown down blocking the Knabe Rd. near Clay Canyon Dr.

A squall produced a short burst of 50-65 mph winds between Cardiff by the Sea and Lake Hodges. The mesonet station at Elfin Forest reported a peak wind gust of 64 mph. Tree damage was also reported.

A swift water rescue to save 2 people and a dog was conducted at the intersection of University Ave. and Aragon Dr. in the neighborhood of Rolando.

Widespread flooding occurred near Gilman Springs Rd. and Soboba Rd. in San Jacinto with multiple water rescues conducted.

A severe squall produced a swath of 60-70 mph winds from Imperial Beach to Lawson Creek. At least 6 mesonet stations reported peak wind gusts in excess of 58 mph including a 68 mph gust at Lawson Creek and 64 mph gust at Boarder Field. Hundreds of trees were downed. Roof damage was also reported. One person was injured when a tree fell on their car in Lakeside.

Rapid water rises after 1500PST flooded parts of Carroll Canyon Rd with 1-2 ft of rushing water. The flow carried dumpsters and debris. Three people were trapped in their vehicle that stalled as the water rose rapidly, resulting in multiple swift water rescues around 1530PST.

Multiple low water crossings were closed due to rapid rises in the San Diego River, including Camino Del Rio and Ward Rd. Several cars were submerged by the rapidly rising waters. The Fashion Valley Transit Center was closed due to flooding. The river peaked at 0215PST on the 21st with a crest of 11.81 ft.

The CHP reported a vehicle in jeopardy of being washed off a bridge near Sandia Creek Dr. and Rock Mountain Rd.

Lifeguards along the San Diego County coast reported 7 to 10 ft surf between the 20th and 24th. Peak sets of 12-15 ft were reported on the 22nd and 21st south of Carlsbad. Two women were swept from the rocks in Sunset Cliffs by surf up to 15 ft between 1700 and 1800PST on the 21st. One woman was killed and the second suffered serious injuries. Two lifeguards were also injured during the rescue attempt. Significant beach erosion and minor coastal flooding occurred along the coast. The Imperial Beach Pier was closed for a time.

Lifeguards reported 7-8 ft surf between the 20th and 24th. Surf peaked on the the 21st and 22nd with 9-10 ft sets in Huntington Beach.

A mud slide blocked both lanes of Old Highway 80.

The Santa Margarita River river gauge at Ysidora recorded a crest of 14.60 ft at 2345PST. This was the 6th highest crest on record and exceeded moderate flood stage by 1.3 ft. Impacts to Camp Pendleton Marine Corps Base are unknown.

Six feet of water inundated an apartment building in City Heights on 48th street. One family nearly drowned due to the flood.

Heavy mountain rain produced flows in the Whitewater River and Palm Canyon Creek that lead to periodic closures of low water crossings in the Coachella Valley, including: Golf Club Dr., Gene Autry Trail., Indian Canyon Dr., Vista Chino Rd., Frank Sinatra Dr., Araby Dr. and Vista Chino.

Very heavy snow fellow over a 48 hour period, with the heaviest snow falling between 0700 and 1900PST on the 22nd. A trace-1 ft of snow was reported between 3,500 ft and 5,000 ft with 1 to 2.5 ft above 5,000 ft. Some local snow totals included: 18-30 inches in Big Bear Lake, 25 inches in Green Valley Lake, 24 end of Mt. Baldy Rd., 20 inches in Barton Flats, 18 inches in Running Springs, Arrowbear Lake, and Forest Falls, 16 inches in Angelus Oaks and Wrightwood, and 12 inches in Blue Jay.

The Long Valley Ranger Station reported 28 inches of new snow. The majority of the snow fell between 1200 and 1900PST on the 22nd. Chain restrictions were required on area highways.

Power lines downed in Hesperia and Phelan. Numerous gusts in the 50 mph range were reported, including a 53 mph gust at Victorville Airport.

Rapid water rises along Temecula Creek caused flooding in south Temecula. Firefighters rescued a woman stranded on a small island in Temecula Creek. The woman was transported to the hospital with minor injuries.

Excessive rain induced flash flooding in the Cajon Wash. A swift water rescue was conducted to pull 2 people from the wash near Swarthout Canyon Road. Further south along the wash, San Bernardino County Public Works closed Glen Helen Pkwy. from Glen Helen Rd. to Cajon Blvd. for an extended period.

Widespread heavy rain brought flash flooding to a large portion of Orange County. A water rescue occurred on Hamilton Ave. at the Santa Ana River in Huntington Beach. Numerous streets from Sunset Beach to Santa Ana to Newport Beach were also flooded with 1-3 ft of water. Numerous reports of vehicles stranded in flood waters were received, including half a dozen along Highway 55.

CHP reported 3 vehicles submerged and stuck in water on Antonio Pkwy. in Las Flores.

A swift water rescue team pulled a man from a submerged car in a small creek near Old Highway 395 and 5th St. in Rainbow. A young boy, also in the car, was swept down stream before rescuers arrived. The boys body was recovered on the 26th.

Pala Temecula Rd. was closed due to flooding and rocks in the roadway.

Heavy mountain rain drained into the deserts leading to flooding along several area roadways. A closure occurred along Highway 18 west of Victorville due to flooding across all lanes.

Swift water rescue conducted near North Golf Course in Sun City.

Cal Fire reported of a swift water rescue along the Pyrite Channel near Van Buren Blvd.

Roadway closure due to flooding on Cole Grade Rd.

Roadway closure at the intersection of Highway 138 and 173 with a swift water rescue and 2 vehicles stranded in flood waters.

Cal Fire and Riverside County Firefighters conducted 2 water rescues along the Temescal Wash in Alberhill near the intersection of Hostettler Rd. and Temescal Canyon Rd. Four vehicles were stranded in 2-3 ft of water.

Highway 83 between Pine Ave. and Highway 71 closed due to flooding along Chino Creek.

Heavy mountain rains produced flows from the Mojave Dam. Flow through the Mojave River lead to a closure of Rock Springs Rd. due to 6-8 inches of water flowing over the low water crossing.