Powerful winter storm arrives in Southern California for Christmas holiday. Here's what to know.
A powerful winter storm has arrived in Southern California for the Christmas holiday, bringing heavy rain and the potential of flooding, weather officials say.
The National Weather Service has issued several warnings and advisories as the atmospheric system over the region is expected to produce between 3 to 6 inches of rain in the coastal and valley areas, and 5 to 11 inches in the foothills and mountains.
An emphasis has been placed on burn scar areas that are more susceptible to flooding, mudslides and debris flows. The NWS has issued a flood watch for much of Southern California through Friday afternoon as rainfall rates could potentially exceed 1 inch per hour during the peak hours of the storm. Weather officials said flash flooding has already occurred in some areas, causing dangerous conditions.
An NWS flash flood warning is also in effect until noon for the southwestern parts of LA County and the southeastern parts of Ventura County. These areas include Thousand Oaks, Simi Valley, Malibu, Woodland Hills, Santa Monica, Beverly Hills, Hollywood, Burbank and Pasadena.
"LA County's gusts pushing over 60 mph, downing trees and power lines in many areas—so this storm is evolving exactly as we have been talking about, and continue to encourage everyone to take these warnings and messages seriously as the accumulative effects of the rain will result in increasingly dangerous and life-threatening conditions as we head through the holiday time period," said Ariel Cohen, National Weather Service meteorologist in charge.
Peak rainfall timing on Wednesday:
- Santa Barbara County: 3 to 7 a.m.
- Ventura County: 5 a.m. to 1 p.m.
- Los Angeles County: 9 a.m. to 4 p.m.
CBS LA has issued a Next Weather Alert through Christmas Day on Thursday for all Southern California communities. A Next Weather Watch has been issued for Friday, which could be upgraded if weather conditions persist.
"Especially in LA County, it's going to continue to get worse," Cohen said. "It will take less and less rain to create more and more impacts as the ground becomes saturated – expect many canyon highways and roadways, areas with terrain to become impassable as rockslides and mudslides increase in severity in coverage."
Cohen urged residents to avoid unnecessary travel during the storm.
Showers are expected to last through Friday and Saturday, with conditions finally drying out by the start of next week.
Evacuation orders and warnings
Evacuation orders have been issued for several burn scar areas, including the Palisades, Eaton, Franklin, Kenneth, Agua, Owen, and Agua fire areas.
"If you decide to stay in your home in an evacuated area ... it could be difficult to leave once the storm begins," said Los Angeles County Sheriff Robert Luna during a news conference Tuesday.
The Orange County Sheriff's Department has issued an evacuation order for Trabuco Creek, Bell Canyon and Hot Springs Canyon near the Airport Fire burn scar. Officials have established a shelter for residents located in evacuation zones at the Foothill Ranch Library Program Annex at 27002 Cabriole Way.
On Monday afternoon, ahead of the storm, the city of Los Angeles issued an Evacuation Warning for those located in the burn scar areas from the Hurst and Sunset Fires, as well as the neighborhood of Mandeville Canyon. The warning will remain in effect until 11 p.m. on Thursday.
San Bernardino County officials issued evacuation warnings for residents who live in Forest Falls, Seven Oaks, Angelus Oaks, Northeast Yucaipa and areas of Oak Glen. They warn communities about the potential for mud and debris flows caused by the heavy rainfall.
Storm-related closures
As the heavy rainfall has already started to impact several communities across Southern California, amusement parks including Six Flags Magic Mountain in Valencia and Knott's Berry Farm in Buena Park have announced they will be closed on Christmas Eve due to the "inclement weather."
The LA Zoo also announced it will be closed on Wednesday, "out of an abundance of caution."
On Tuesday night, LA County Public Works and Caltrans officials implemented road closures due to potential storm impacts and recovery work.
Los Angeles County road closures:
- Malibu Canyon Road Soft closure (emergency vehicles only) between Francisco Ranch Road/Adamson Flats Road and just south of Piuma Road
- Tuna Canyon Road Hard closure between approximately 2870 Tuna Canyon Road (Gate) and Pacific Coast Highway
- Chantry Flat Road Soft closure (emergency vehicles only) between 1209 Arno Drive to Chantry Flat Recreation Area
- Glendora Mountain Road hard closure between North of Big Dalton Canyon Road to East Fork Road
Caltrans road closures:
- Topanga Canyon Boulevard/State Route 27 Fully closed between Pacific Coast Highway and Grand View Drive
- Pacific Coast Highway (State Route 1) is expected to remain open, with crews actively monitoring areas most susceptible to debris flows.
The City of Malibu Public Safety Department has issued multiple road closures due to flooding. Topanga and Malibu Canyons, Rainsford Place, Bonsall Drive at Arizona crossing are all closed.