A strong storm system is expected to drench much of Southern California with rain and cover mountaintops with snow beginning late tonight and peaking Tuesday, 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. Tuesday, 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 will be take effect at 3 a.m. Tuesday and remain in place until 6 p.m. Tuesday 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 Tuesday in Orange County coastal and inland areas and in the Santa Ana Mountains and foothills.
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 Monday and Tuesday and lows dropping into the 30s Tuesday night in the mountains and parts of the San Fernando Valley, and into the 20sin 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.
Because of the rain, the city-run COVID-19 vaccine and testing clinics at Houghton Park will move indoors on Dec. 14 to the Houghton Park Community Center, located at 6301 Myrtle Ave., according to Long Beach health department spokesperson Jennifer Rice Epstein. Vaccine and testing operations at Long Beach City College, Pacific Coast Campus and Veterans Stadium will not be open on Dec. 14 because of the rain, and will reopen later this week, Epstein added.
According to the city, sand and sand bags will be available at the following fire stations:
- Station 7, 2295 Elm St.
- Station 12, 1199 Artesia Blvd.
- Station 13, 2475 Adriatic Ave.
- Station 14, 5200 Eliot St.
The sand and bags are for residents only, the city said. Residents must bring their IDs and can pick up a maximum of 10 bags, the city said. Residents should bring their own shovel or tool when collecting sand. It is illegal to pick up sand from the beaches, the city added.
This story was updated to include information on rain-related closures from the City of Long Beach.