The second day of a fall storm has prompted flood alerts in recent burn areas and major road closures throughout Southern California.
Woolsey and Hill Fires:
Earlier, a flash flood warning was in effect for the Woolsey and Hill fire burn areas, in areas near the Los Angeles and Ventura County border, according to officials. Areas of concern included Malibu Canyon and Las Virgenes Roads as well as Kanan Dume Road in the Santa Monica Mountains and Pacific Coast Highway north of Malibu.
Pacific Coast Highway reopened hours after it was shut down in both directions from Kanan Dume Road to the Ventura County line due to mud and water in lanes. Mud and debris had been blocking northbound lanes and portions of the southbound lanes at Leo Carrillo State Park beginning around 7:30 a.m., according to the CHP's incident information page.
The roadway fully reopened around 5 p.m., but motorists were still urged to use caution as cleanup continued along the shoulders.
Residents in recent burn areas spent the past few days preparing for possible mudslides and debris flows.
As of 1 a.m., more than 2 inches of rain had already fallen in Agoura, with more rain to come, according to the Weather Service.
About 1.9 inches fell in downtown L.A., breaking the date's previous record of 1.01 inches set in 1997.
Holy Fire and Canyon Fire:
A flash flood watch was issued for areas affected by the Holy and Canyon fires late Thursday morning because of the potential for flooding and debris flow and would remain in effect until at least midnight.
The watch included inland areas of Orange County, the Santa Ana Mountains and foothills, as well as areas in the western Inland Empire of Riverside County, according to the National Weather Service.
Mandatory evacuations were issued in Orange County for residents within Trabuco Creek, according to the Orange County Sheriff's Department. Residents were being told to shelter in place a short time later as access to roads was blocked off. Hard road closures were in effect in Trabuco Canyon at Rose Canyon and Trabuco Canyon at Plano Trabuco.
Residents of Rose Canyon were advised to shelter in place because of the Trabuco Canyon closure.
The orders would remain in place until around noon Friday, sheriff's officials said.
Evacuation maps and additional information are available at ocgov.com/emergency.
In Riverside County, mandatory evacuations were in effect in the Lake Elsinore area for Amorose, Alvarado A and Laguna A Thursday night.
The order was downgraded from mandatory to voluntary for other areas: Alberhill, Glen Ivy A and B, Glen Eden, Grace, Horsethief A, Matri, McVicker A, Rice and Withrow A, according to Riverside County officials.
"More rain is expected in the Holy burn area and the potential still exists for dangerous conditions, even in the zones where evacuation is voluntary," a statement from the county said. "People must remain vigilant, monitor official sources about weather conditions and any changes in the situation."
Riverside County residents can visit rivcoready.org/stormready to determine if they're in a mandatory evacuation area.
"Debris flows are extremely dangerous and happen suddenly often with little time to act," the weather service advised. "It may even not be raining at your location to be impacted by a debris flow."
Photos shared by Cal Fire Riverside show extensive storm damage in the Holy Fire burn scar in Lake Elsinore and surrounding areas. Roads were impassable after becoming caked with mud and tumbling debris and vehicles became trapped.
The 5 Freeway was fully reopened after being closed northbound at Parker Road and southbound at the base of the Grapevine after snow accumulated on the highway, CHP officials in the Newhall area reported.
Traffic had been backed up for miles in the area.
Inland flooding in L.A., San Bernardino and Riverside counties:
A flash flood warning was in effect until 7 p.m. across the San Bernardino-Riverside county line, including San Bernardino, Moreno Valley and Redlands. Earlier in the day, a separate flash flood warning was in place in Victorville, Hesperia and Apple Valley.
A flood advisory had been in effect for Los Angeles County until 1:45 p.m.
The heaviest rainfall was reported in the San Gabriel Valley near Rowland Heights, Walnut, Diamond Bar, La Verne
and Pomona, where the rainfall rate was between 0.50 inch and 0.75 inches per hour, according to the weather service.
Flooding was reported in inland areas of L.A. County, including Encino, where cars were inundated on rain-swelled roadways, aerial video from Sky5 showed.
Roadway flooding is likely to continue Thursday afternoon, the weather service reported.
Showers are expected to continue on and off throughout the day before sunny skies return on Friday.