Roads, schools close as heavy rain douses Southern California

Heavy rain pounded Southern California again Tuesday as yet another storm system thundered over the region, causing localized flooding and debris flows that forced closures of roads, freeway lanes and even some schools.

The powerful storm, which was expected to linger over Los Angeles, Orange and other southern counties through Tuesday, dumped more than 10 inches of rain in some areas overnight, with the bulk falling in Ventura County.

As of early Tuesday morning, roughly 6 inches of rain had fallen in Porter Ranch and Woodland Hills, while about 5 inches fell in Bel Air and Beverly Hills. More than 4 inches fell on Alhambra, Pasadena, Castaic and Newhall as of 4 a.m., according to the National Weather Service.

Mountain areas received far more rain, with Warm Springs recording 8 inches of rain by 4 a.m. More than 7 inches fell in the Sepulveda Canyon.

By Tuesday morning, however, the steady rain that soaked much of the region began giving way to more sporadic showers, but NWS forecasters warned that the Southland was not yet done with the rain.

“There will be periods of heavy rain, strong winds, possible flooding and a chance of strong thunderstorms,” according to the NWS.

The overnight downpours led to isolated flooding and debris flows, making for a sloppy morning commute and warnings from local authorities for residents to stay off the roads if at all possible.

Mud flows, sliding rocks and fallen tree limbs made driving treacherous on canyon roadways out of the San Fernando Valley, frustrating drivers on critical routes such as Laurel, Coldwater and Benedict canyons. Roads in the Malibu and Topanga areas were also impacted, including a large boulder that fell onto Malibu Canyon Road in the Santa Monica Mountains, forcing a closure. All roads in the Sepulveda Basin area were also closed due to flooding.

With driving rendered difficult to impossible, all schools in the Malibu area were closed for the day, with students reverting to remote learning. Campuses in Santa Monica remained open.

The Los Angeles Unified School District closed Topanga Elementary School for the day due to the storm conditions, with all students and staff moved to Canyon Charter Elementary School in Santa Monica.

The storm also sporadically knocked out power to thousands of residents.

Late Monday night, as rain began pouring over the area, Los Angeles Fire Department and other first responders made a dramatic rescue as they pulled people from a large, water-filled sinkhole in Chatsworth that swallowed at least two vehicles — one on top of the other. There were also muddy debris flows on streets and a quarter-acre landslide on a hill in Hollywood Hills West.

Much of SoCal was under watches and warnings for floods, high wind and high surf. Flash flood alerts and watches were in effect in parts of Los Angeles and Orange counties, with forecasters warning of continued possibilities of flooding along the Los Angeles County coast and in mountains, downtown Los Angeles, the San Fernando, Santa Clarita, San Gabriel and Antelope valleys and inland areas including Hollywood, Compton, Long Beach, Pomona, Downey, Norwalk, East Los Angeles, Culver City, Lakewood and Beverly Hills.

A flood watch also was in effect in Orange County’s coastal areas, inland areas including Santa Ana, Anaheim, Garden Grove, Irvine, Orange, Fullerton and Mission Viejo, and the Santa Ana Mountains and foothills.

Due to the threat of flooding and debris flows in recent burn areas, Los Angeles County officials issued an evacuation warning Monday for residents in the Lake Hughes and Kings Canyon area. Residents were warned to prepare to evacuate by gathering important materials and being ready to leave quickly.

The city of Duarte issued a “yellow alert” for residents of roughly 25 homes near the Fish Fire burn area from 4 p.m. Monday through 6 p.m. Tuesday. The alert imposes restrictions on street parking on Mel Canyon Road between Brookridge and Fish Canyon roads, and on Deerlane Road between Mel Canyon and Greenbank Avenue.

The NWS also warned of gales and high surf expected over the region through Tuesday.

Snow levels were expected to remain above 8,000 feet Monday evening, but could fall as low as 6,000 feet on Tuesday, forecasters said.

Forecasters said the shower activity will slowly decrease by later Tuesday afternoon and into the evening, with the area expected to dry out overnight and into the next few days.

In response to the seemingly relentless series of storms, President Joe Biden approved an emergency declaration for the entire state of California on Sunday and authorized the Federal Emergency Management Agency to coordinate disaster relief efforts and provide emergency resources.

A high wind warning was in effect for parts of Orange County until 4 p.m. Tuesday. South to southeast winds from 15 to 25 mph with gusts from 35 to 40 mph were expected in Huntington Beach, Costa Mesa, Newport Beach, Laguna Beach, San Clemente, Santa Ana, Anaheim, Garden Grove, Irvine, Orange, Fullerton and Mission Viejo.

Temperatures will stay cool throughout the week, with highs in the lower 60s. Overnight lows will mostly be in the 40s and lower 50s, but will drop into the 30s in the mountains and high desert.

Health officials issued a cold weather alert for Lancaster and Mt. Wilson, where near-freezing or sub-freezing temperatures are expected. The alert will be in effect Tuesday through Friday in Lancaster, and Wednesday in Mt. Wilson, according to the Los Angeles County Department of Public Health.

Partly sunny skies will return Wednesday and Thursday, but more rain is possible next weekend, possibly as early as Friday night, according to the NWS.

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