LOS ANGELES (CNS) – A strong storm system is expected to drench much of Southern California with rain and cover mountaintops with snow peaking later today, raising fears of flooding and potential debris flows.
National Weather Service forecasters previously dubbed it “the most significant storm of the season.” Coastal areas and the valleys could get up to 3 inches of rain during the storm, while mountains and foothills could see up to 5 inches.
“Due to the threat of heavy rain bands and a slight chance of thunderstorms capable of producing high-intensity short-duration rainfall, there will be the potential for debris flows over recent burn areas as well as significant roadway flooding,” according to the NWS.
Rain will progress from northwest to southeast, with the heaviest rain over Los Angeles County expected to fall between 7 a.m. and 5 p.m. today, forecasters said.
“On Tuesday the system will move into L.A. County and will likely make a mess of rush hour traffic. A very strong jet will move over the area,” forecasters said.
The NWS issued a flash flood watch that took effect at 3 a.m. today and remains in place until 6 p.m. in recent county burn areas — from the Bobcat, Ranch 2, Dam, Lake, and Palisades fires. Forecasters warned that those areas could see intense downpours with an inch or more of rain per hour.
“Residents near these burn scars should prepare for potential flash flooding and debris flow impacts,” according to the NWS.
A flood watch will also be in effect throughout today in Orange County coastal and inland areas and in the Santa Ana Mountains and foothills.
The Orange County Sheriff’s Department issued a voluntary evacuation warning for residents in the Bond Fire burn area, including Modjeska, Silverado, and Williams canyons. People with disabilities or who are otherwise in need of evacuation assistance can contact the sheriff’s department at 714 647-7000.
A “care and reception center” was established at Lake Forest Sports Park, 28000 Rancho Parkway, for people heeding the voluntary evacuation warning and looking for a place to wait out the storm. The American Red Cross will operate an overnight shelter at the same location for evacuated residents.
Three Red Cross shelters are open to provide safe refuge and resources for anyone affected by the storm.
Besides Lake Forest, 28000 Rancho Parkway in Orange County, the American Red Cross of San Bernardino County has opened a shelter at Redlands
East Valley High School, 31000 E. Colton Ave. in Redlands, and the American Red Cross of Riverside County have opened a shelter at the Albert A. Chatigny Senior Community Center, 1310 Oak Valley Parkway in Beaumont.
The storm will also bring strong winds to the area, likely sweeping over and down the San Gabriel range and bringing warning-level gusts to the Antelope Valley late tonight.
“Periods of strong south to southwest winds are also expected with this system, especially in the mountains, deserts, and high elevation valleys where damaging wind gusts of 50 to 65 mph will be likely,” according to the NWS. “Remaining coastal and valley areas will see widespread wind gusts of 30 to 50 mph. In addition, localized wind gusts up to 50 mph will be possible anywhere that has thunderstorms or heavier convective showers.”
About 1 to 3 feet of snow will fall on mountains above 7,000 feet, but there could be some snow accumulation in the Grapevine area.
The storm will be accompanied by chilly temperatures, with daytime highs in the 50s today and lows dropping into the 30s tonight in the mountains and parts of the San Fernando Valley, and into the 20s in the Antelope Valley.
Health officials advise the public not to swim or surf in ocean waters at and around discharging storm drains, creeks and rivers after significant rainfall due to a possible increase in bacteria, chemicals, debris, trash, and other public health hazards.