A powerful storm system slammed the Southland Tuesday with heavy rain, high winds and mountain snow, leading to flooded roadways, dangerous driving conditions and growing concerns about mud and debris flows in recent burn areas.
By 8 a.m., some mountain and foothill areas had already received as much as 7 inches of rain, while coastal and valley areas had received between 1 and 3 inches, according to the National Weather Service.
“Rain, heavy at times, and high elevation snow will continue through the afternoon. Gusty and potentially damaging winds are expected over the area today as well,” according to the NWS.
Forecasters noted there is still a threat of some thunderstorms developing, meaning the potential for even heavier downpours and continuing the risk of flooding.
Meanwhile, the storm also brought high winds, with gusts up to 73 mph recorded in some mountain areas and from 30 to 45 mph in coastal and valley areas.
Snow also fell in the mountains at elevations of 6,000 to 7,000 feet. Forecasters said earlier that as much as three feet of snow could accumulate in the mountains.
Reports of flooding amassed throughout the morning rush hour. In northern Los Angeles County, a stretch of Lake Hughes Road had to be closed due to mud and debris that cascaded over the roadway in Castaic.
Near Los Angeles International Airport, stormwater flooded at least one southbound lane of the Sepulveda Boulevard tunnel, leading to traffic delays as crews worked to clear the water.
Fire crews were on high alert near the Los Angeles River, which was filled with a rushing torrent of water as the storm continued. Around 9 a.m., firefighters responded to the river near Washington Boulevard in the downtown area due to a car that was reported to have gone into the water. Another person was plucked from the river in the Sylmar area.
Traffic signals were knocked out of service on Pacific Coast Highway from Coastline to Cross Creek in the Malibu area, making already treacherous driving conditions even more dangerous.
Power outages were also reported throughout the area. By mid-morning, customers were reporting outages in an array of areas covered by the Los Angeles Department of Water and Power, including El Sereno, Highland Park, Westwood and Studio City. Southern California Edison was reporting outages affecting more than 6,000 customers throughout Los Angeles County, although it was unclear how many of them were storm-related.
The rain is expected to keep falling through the afternoon, tapering off by late afternoon and leading to a dry Wednesday, before a much smaller, much weaker storm moves into the area Thursday.
The NWS issued a flash flood watch that will be 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 is also in effect 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 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 Red Cross also opened a shelter at Redlands East Valley High School, 31000 E. Colton Ave. in Redlands, and the American Red Cross of Riverside County opened a shelter at the Albert A. Chatigny Senior Community Center, 1310 Oak Valley Parkway in Beaumont.
The storm will keep things cool throughout the day, with daytime highs in the 50s Tuesday and lows dropping into the 30s Tuesday night 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.
The Los Angeles Fire Department and county Office of Emergency Management issued a series of reminders related to the potential for mud and debris flow. Among them were:
— Acquire any needed sandbags and instructional materials at your local Los Angeles County fire station.
— Have an emergency plan in place.
— Monitor radio and TV news closely for information about weather conditions and flooding in your area.
— If your neighborhood is evacuated, identify important items to take (e.g., computers, photos, important documents, medications, and other essential items for your family and pets).
— Have enough food and water to supply your family for at least a 72-hour period.
— Remember to include a radio and flashlight with fresh batteries in your emergency kit.
— Stay away from flood control channels, catch basins, canyons, and natural waterways that are vulnerable to flooding during periods of heavy rain.
— Do not attempt to cross flooded areas and never enter moving water on foot or in a vehicle.
“Our emergency response officials are world-class and will stand ready to defend lives, property and infrastructure if there are emergencies caused by this storm,” said Kevin McGowan, director of the county Office of Emergency Management. “But, we need collaboration from the public. It is critical for residents to be aware and prepared so that they can help keep themselves safe.”