The heaviest part of the storm system that has hit the Los Angeles area and other parts of the south has gradually subsided by Christmas morning, but showers are expected throughout the day, heavy in the area at times, and the risk of mudslides remains in recent burned areas including from the Palisades and Eaton fires.
The forecast and heavy rains prompted LA Mayor Karen Bass to declare a state of emergency.
Overall, the chance of rain across Los Angeles County is 50% during the day Thursday and 80% overnight, according to the National Weather Service.
The rain also led to a sewage spill of about 10,000 gallons, county officials said, creating hazardous conditions a third of a mile upstream from Cabrillo Beach in San Pedro, where visitors are advised to avoid contact with water and wet sand. The county’s Department of Public Health is sampling the water, and the closure will continue until bacteria levels reach health standards.
By noon in LA County, meteorologists are predicting between a tenth and a quarter of a new inch, although local thunderstorm activity will bring more rain than that in other areas.
Rain is expected to increase overnight, with the forecast averaging one to three quarters of an inch of rain.
The weather service also issued a flash flood warning for southwest Los Angeles County on Thursday.
“At 8:53 am the Doppler radar indicated a thunderstorm bringing heavy rain to the warned area,” the warning warned. “Flooding is ongoing or expected to begin soon.” The warning warned of “flooding of small streams and creeks, urban areas, highways, roads and subways and other poor drainage areas and low-lying areas.”
Areas expected to experience flooding include “Eastern Malibu, Topanga State Park, Pacific Palisades, Topanga Canyon Road through the Santa Monica Mountains, Malibu Canyon and Los Virgenes Roads through the Santa Monica Mountains and Mandeville Canyon.”
On Thursday morning, there were severe thunderstorms throughout southern Ventura County and radar storm tracking in a line from 6 miles south of La Conchita to near Point Mugu. Wind gusts were up to 50 kilometers per hour, according to the weather service: “Although not immediate, the Doppler Radar showed a weak circulation in this activity, and a short, weak typhoon cannot be ruled out.”
On Wednesday, the storm system dumped 2 to 4 inches of rain across the region, with some areas receiving 4 to 8 inches and 10 inches in the mountains and hills.
Since early Wednesday evening, the Los Angeles Fire Department has dispatched crews to three river rescue incidents. Additional information was not immediately available.
Meanwhile, the LA Police Department responded to more than 100 traffic accidents. There were no traffic-related injuries or deaths reported. The city’s transportation department was working to restore five road signs and city crews were responding to “about 500 tree emergencies.”
Across the region, a winter storm warning remains in effect for the Sierra Nevada above 7,000 feet above sea level from Yosemite to the Lake Isabella area through Friday, with 12 snowfalls per day expected. By the weekend, there will be snow on the ground in the lower elevations of about 5,000 feet above sea level over the weekend.
The cities of Tehachapi, Frazier Park, Lebec, and Grapevine were under a high wind warning until 4 p.m. Friday, with southerly winds of 15 to 25 mph and gusts of up to 45 mph — conditions that could affect drivers heading north or south on the highway that cuts through the Grapevine Mountains.
“Damaging winds will bring down trees and power lines,” said the National Weather Service. “It is expected that there will be a power cut in many places, it will be difficult to travel, especially in high-class vehicles.”
The NWS warned that those living in the most affected areas should “stay on the ground floor of your home during the storm and avoid windows. Be aware of falling debris and tree limbs. Be careful if you must drive.”
Mayor Bass said in a statement: “We are making all resources and tools available to assist the city’s ongoing response… I urge all Angelenos to be safe and be extra careful on the roads if you absolutely must. Please do not take this storm lightly – follow official guidance, plan ahead, and sign up for emergency alerts at NotifyLA.org.”
Showers are expected to start on Friday evening as dry and warm weather returns by the middle of next week.
