The first major El Niño storm of the season slammed into Southern California on Tuesday, setting new rain records for the day and causing various traffic headaches.

Tuesday brought more rain to Los Angeles than any day in 2015 except for one, Sept. 15, when the remnants of Hurricane Linda washed ashore, said Bill Patzert, climatologist with the NASA Jet Propulsion Laboratory in La Cañada Flintridge.

“This is not a bashful El Niño. This is a brash El Niño,” Patzert said. “Definitely, it’s impressive.”

The storm set rainfall records for the day in several places including Los Angeles International Airport, as well as to the north in Stockton and Redding.

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The latest rain, measuring from Sunday, has been significant, pouring 1.3 inches in Laguna Hills, 1.39 inches on downtown L.A., 1.45 inches in San Juan Capistrano, 1.64 inches in Ventura, 1.75 inches in Beverly Hills, 1.79 inches in South Gate, 1.97 inches in San Onofre, 2.2 inches in Pasadena and 2.46 inches in Alhambra as of 2 p.m. Tuesday.

The heavy rain led to flooding on several roadways, including the 101 Freeway between Ventura and Santa Barbara. On Malibu Canyon at Pacific Coast Highway, boulders fell into the roadway in what the California Highway Patrol labeled a mud, dirt and rock slide. Four vehicles were damaged.

The heaviest rain of Tuesday’s storm was expected to move out in the afternoon before the start of the evening commute, although there could some lingering shower activity, according to the National Weather Service.

“The storm today was moving in very quickly; tomorrow looks to be sort of the same deal as today,” said National Weather Service meteorologist Emily Thornton. “The bigger story is that it’ll be over a longer period of time” — and possibly dump more rain than Tuesday’s storm, which was passing through relatively quickly.

Heavy rain is expected to resume in the late morning hours Wednesday, Thornton said, and is forecast to persist. A break in the rain may come by Friday, but another system is again expected to hit Los Angeles on Saturday night into Sunday. It’s also possible that rain could return Monday.

On Wednesday, recently burned areas could again be at risk for flash floods, the National Weather Service in Oxnard said in a bulletin.

City officials have prepared for the rain, distributing sandbags and offering shelters. In Los Angeles, where officials have been preparing for months, Mayor Eric Garcetti said the city was faring well amid the wet weather.

No major roads had been closed, he said, and fewer than 1,000 of the city’s electricity customers had lost powere in the storm.

“We have been working for months on this,” Garcetti said. “Today is the day that it is here.”

Garcetti said outreach workers had been busy visiting homeless encampments in recent days and had persuaded some people to seek shelter, but that a number of others had refused help and still remained in flood-prone areas.

“We feel very comfortable in terms of the [shelters’] capacity,” Garcetti said. “Part of it is the difficulty of getting people to come in. That’s not for lack of workers.”

Amid Tuesday’s storm, Los Angeles County officials said they were struggling to secure federal funds for flood control and the removal of debris from the Los Angeles River.

Officials with the county Department of Public Works said they had learned Monday that the Army Corps of Engineers had not received the $4.5 million needed to do maintenance on the river basin in the lead-up to El Niño.

The county’s elected supervisors voted to send a letter to Congress and to the assistant secretary of the Army, calling for them to immediately appropriate the funding needed for the area of the river between its Burbank western channel and the 2 Freeway.

“Without this maintenance, this portion of the Los Angeles River will only provide a low level of flood protection, which is especially critical under the current El Niño conditions,” supervisors Hilda Solis and Sheila Kuehl wrote.

But the supervisors also took county staff to task for not alerting them sooner that the funding was in question.

“Right now, we’re playing catch-up in the middle of a storm,” Supervisor Michael D. Antonovich said. “It’s that type of lack of planning that I get frustrated with.”

Throughout Southern California, motorists and residents slogged through the rain, clutching umbrellas and sloshing through large puddles. Traffic along Los Feliz Boulevard flowed steadily despite the downpour, but drivers laid on their horns as cars splashed through the water.

Roberto Carrera said his usual 30-minute commute to his job at the Morrison restaurant and pub took more than an hour Tuesday because of heavy traffic on the freeways. He said there seemed to be an accident on each of the three freeways he takes to get to work.

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“I lived in England for a while, so I’ve seen worse,” said Carrera, 23. “But hopefully it does help us out a little bit,” he said, referring to the drought.

CHP officers saw an uptick in calls for service Tuesday, dealing with reports of flooding and with mud and rocks on the freeways, said Officer Juan Galvan, a public information officer for the agency.

“We want everybody to slow down, especially during this rain,” Galvan said. “Be safe out there.”

Galvan warned motorists to avoid the carpool and slow lanes, where there are typically water drains that back up and cause water to pool.

Rain on Tuesday morning hammered the Solimar Beach area, where a brush fire Christmas weekend had raced through the mountains, across the 101 Freeway and down toward Pacific Coast Highway. The smell of smoke was still hanging in the air, mixing with the sea breeze as workers rushed to clear mud that had brought traffic on the southbound 101 to a crawl. They kept digging, unsure how deep the mud had gathered.

The median on the 101, at the bridge on Dulah Road, had swelled with mud and water, blocking two drains. Up to 6 inches of mud swept across southbound lanes by about 9:30 a.m. Tuesday morning.

Authorities said they were concerned that the charred and denuded slopes would come crashing down onto the 101 with the morning rains. But the slopes for the most part held up, with only a little debris tumbling onto the road. Mudflow advisories for the area were lifted by 12:30 p.m.

Authorities said they were relieved that the burned area held in place — at least for now.

“This was practice for the big ones we’re anticipating this year,” said CHP Sgt. Joseph Davy. “I don’t want to call it a ‘dry run,’ this was more of a ‘wet run’ for what’s going to come.”

Some mudflows were also reported in Silverado Canyon and in Newhall.

The Los Angeles Fire Department reported flooding at the Sepulveda Basin. Areas where roadways were closed included Burbank Boulevard and the 405 Freeway, Burbank Boulevard and Hayvenhurst Street, and Woodley Avenue and Victory Boulevard.

The LAFD also received a report of a woman in a wash in Tujunga needing rescue at 11:23 a.m., said Margaret Stewart, department spokeswoman, but no one was found and the search was called off in the afternoon.

A second rescue call came out of Encino at 12:51 p.m, Stewart said, but when LAFD crews arrived on the scene, Los Angeles Police Department officers had already helped two people out of a wash.

Road closures related to the storm occurred throughout Southern California on Tuesday, with flooding shutting down Colorado Boulevard between Santa Anita Avenue and San Antonio Road. The northbound 405 Freeway was closed at the 5 Freeway in Sylmar due to a multi-vehicle crash involving a jackknifed big rig.

In Montebello, a big rig went through the center median and became stuck.

Beginning Tuesday morning, a voluntary evacuation was in effect for some residents in the Camarillo Springs area, because of the potential for mud and debris flows, according to the Ventura County Sheriff’s Office of Emergency Services. A voluntary evacuation was also in effect in Silverado Canyon.

Flash flood watches were in effect through late Wednesday for wildfire burn areas in Los Angeles and Ventura counties and northern San Luis Obispo County. A winter storm warning was in effect through early Thursday morning in the mountain areas of Los Angeles and Ventura counties.

brittny.mejia@latimes.com

Follow me on Twitter @brittny_mejia

Staff writers Abby Sewell, Sarah Parvini, Peter Jamison and Taylor Goldenstein contributed to this report.