A cold front that brought wind and heavy rain to California on Thursday unleashed debris flows in fire-ravaged neighborhoods, triggering evacuations and school closures as crews up and down the state rescued people trapped in homes and cars and, in one case, a man clinging to a tree in the Los Angeles River.
In Southern California, the storm dumped a significant amount of moisture on the Holy fire burn area, where a mixture of fast-moving mud and branches tore down a creek in Trabuco Canyon. Other flows powered through Lake Elsinore — where crews rescued an elderly man who was stuck in Rice Canyon and removed two feet of mud from the garage of someone’s home — and closed a portion of Temescal Canyon Road in Corona.
In Forest Falls in San Bernardino County, a mudslide trapped vehicles and prompted the California Highway Patrol to close Highway 38 between Valley of the Falls Drive and Sugar Pine Circle. Dime-sized hail was reported in the Santa Barbara area.
The National Weather Service issued a flash flood watch through early Friday in burn areas of Orange, Riverside and San Bernardino counties. The soil in burn areas cannot absorb a lot of moisture, so heavy rainfall can lead to fast-moving flows containing mud, debris and even trees and boulders. When rain falls over time, it can be gradually absorbed or dispersed, but when areas see rapid runoff, entire hillsides can come down without warning, sometimes with deadly results.
Monte Nido, along the east side of the Woolsey fire burn zone near Malibu, saw just under half an inch of rain in 24 minutes Thursday morning. In the Malibu Park area, crews were cleaning up a mudslide on Cuthbert Road between Horizon and Busch drives.
Residents whose homes were spared in the blaze placed sandbags around their properties in preparation for the storm. Rain caused football-sized rocks to fall from hillsides along Decker Canyon, Kanan and Malibu Canyon roads. Flooding from Zuma Creek near the state park in Malibu also forced some road closures.
The rain also prompted Pepperdine University to cancel classes at its Malibu campus Thursday and caused some minor flooding at Wilshire Country Club in Hancock Park.
Shortly before 11 a.m., firefighters used a helicopter to rescue a 50-year-old man who was clinging to a tree in the raging Los Angeles River in Atwater Village. The man, who authorities suspected was homeless, was taken to a hospital to be treated for hypothermia.
Slick roads also caused a series of traffic problems and freeway closures across the Southland, frustrating commuters. A jackknifed semi truck carrying 20,000 pounds of soft drinks completely closed the westbound 118 Freeway at Topanga Canyon Boulevard in Topanga. Two lanes of the eastbound 134 Freeway in Eagle Rock were closed for several hours after a big rig crashed into an embankment.
Road conditions also proved to be treacherous for first responders. Four firefighters were injured after they were struck by a car while responding to a crash in Ontario.
Portions of Highway 1 in Big Sur remained closed Thursday at its most vulnerable slide points after rain battered the coast. The iconic roadway may reopen Friday morning after the storm has passed.
Already congested rainy-day traffic in Northern California was made worse after officials were forced to close two northbound lanes on Interstate 5 in Sacramento when a section of the roadway crumbled, according to the California Highway Patrol.
The heaviest downpour passed through the northern part of the state overnight Wednesday, dumping up to an inch and a half of rain on the Camp fire burn area and roughly an inch on the Mendocino Complex fire scar. The burn areas in Shasta County received even more of a soaking, with 1 to 3 inches of rain in some areas, according to forecasters.
A flood of mud and debris washed through some roads in the Camp fire burn area, causing about 50 drivers to be stranded in their vehicles, said Rick Carhart, a spokesman for the Butte County unit of the California Department of Forestry and Fire Protection. Once the flooding subsided, fire crews escorted them out.
A swift-water rescue team used a boat to evacuate people out of three homes on Honey Run Road in Butte Creek Canyon. It’s unclear if their homes were flooded or if they were trapped behind floodwaters.
The Butte County Sheriff’s Office ordered evacuations between the 200 block of Honey Run Road and Skyway, including Horse Run Lane. Vehicles were also stuck on a flooded Highway 99 south of Chico, CHP Officer Logan Callahan said.
Redirecting traffic from the highway has been complicated because smaller roadways typically used as detours also are flooded, Callahan said. A watershed emergency response team worked in the area of Paradise to identify spots that could be prone to flash floods and mudslides. Crews cleared drainage ways and removed burned trees that could topple, Butte County spokeswoman Callie Lutz said.
The town of 27,000 has been under mandatory evacuation orders for three weeks since the Camp fire swept through, destroying thousands of homes and killing at least 88 people. Residents could begin returning early next week, but only if the storm doesn’t hinder efforts to clear roads and restore power, officials said.
Times staff writer Alejandra Reyes-Velarde and the Associated Press contributed to this report.