In the Los Angeles Area, Snow Up High, and Flooding Down Below

LOS ANGELES — As steady snowfall continued to present hazards in the mountains of Southern California on Saturday, residents at lower elevations dealt with the fallout from a more familiar threat: flooding.

Intense rains and powerful winds that pounded Los Angeles and surrounding counties on Friday night and early Saturday produced significant flooding in urban areas, downed trees and threatened to cause mudslides.

Multiple water rescues were conducted across counties because of rising waters, said Ariel Cohen, a meteorologist for the National Weather Service in Los Angeles. One person in Santa Barbara County, which also experienced some flooding, was injured after strong winds caused a tree to fall into a home, and in Inglewood, falling trees crushed a line of cars, taking out power lines, he said.

One person died after a vehicle drove off the road and into a flood control area, though it was not immediately clear whether the death was related to the storm, said Kerjon Lee of Los Angeles County Public Works.

Meteorologists said that the most severe effects of the storm at lower elevations could be over, but travel on the roads remained dangerous.

Estefany Gomez of Los Angeles was driving through snow in the Sierra Pelona Mountains in Los Angeles County when she lost control of her Nissan Altima while going downhill. She was driving in snow for the first time and, trying to brake, skidded off the road and into a small pond of near-freezing water. Her family members traveling in another vehicle rushed to pull her out.

No one was injured, but Ms. Gomez was rattled. “I’m still shaky and nervous,” she said by phone.

Elsewhere, portions of Interstate 5 winding through Los Angeles County — including the Grapevine, a 40-mile stretch that goes up to Kern County — were closed on Saturday because of flooding, snow and mudslides. And a 20-mile segment of State Route 14 in Acton, an unincorporated area in northern Los Angeles County, was closed for much of Saturday, snarling southbound traffic for miles. It reopened by midafternoon.

It is rare for the stretch of freeway, lying around 2,000 feet above sea level, to close because of weather conditions, said Eric Menjivar, a spokesman for Caltrans, California’s Department of Transportation, referring to State Route 14. Working 12-hour shifts, 24 hours a day, work crews had plowed more than 200 miles of freeway lanes on Saturday. The elevations where snow fell “really dropped” on Friday night, he said.

“We’re having a lot of flooding,” Mr. Menjivar said. “It’s a slow-moving storm and the rain has been really consistent.” He added later that the snow “has been really relentless.”

On Saturday afternoon in Los Angeles, the rain, which had stopped in the late morning, grew heavy again. The weather left some residents scrambling to change their weekend plans for outdoor events, typically a sure thing this time of year in Los Angeles. The season-opening match on Saturday between Major League Soccer crosstown rivals L.A. Galaxy and LAFC in Pasadena was postponed because of forecasts that included potential lightning.

Six Flags Magic Mountain in Los Angeles County and Knott’s Berry Farm in Orange County were closed, and Little League opening day parades were canceled because of wind and rain.

“It’s been a big disappointment,” said Tracey Lee, 48, a resident of the coastal community of Palos Verdes Estates near Los Angeles, who had spent three months planning opening day celebrations for the local Little League.

The festivities included a two-mile parade of double-decker buses, trolley cars and floats on trailers led by police and fire vehicles down one of the small city’s main thoroughfares. About 2,000 people were expected to be at the event as participants or spectators.

“We don’t have another choice,” she said, lamenting the cancellation. “They say you live in this area for two reasons: Halloween and opening day. It’s something the whole community looks forward to every year.”

Along with the disappointment, Ms. Lee said her neighborhood also experienced power outages during the week and downed trees.

The storm has already set records. On Friday, Los Angeles International Airport received a record 2.04 inches of rain. Earlier in the week, Los Angeles County issued its first blizzard warning since Feb. 4, 1989.

“It’s been many years since we’ve had such a widespread coincidence of all of these hazards at the same time,” Mr. Cohen said.

The United States and other countries have already seen more frequent extreme rainstorms as the world warms. The frequency is likely to increase as warming continues, in part because warmer air holds more moisture.

Almost 15 inches of rain have fallen in parts of Los Angeles County over the past four days, the Weather Service estimated.

In the mountains around Los Angeles, winter storm warnings remained in effect. More than four feet of snow had accumulated by Saturday morning, and the total could double by the end of the day, with whiteout conditions on roads.

In Northern California, which felt the impact of this storm earlier in the week, residents are facing another dose of wintry weather early next week. Yosemite National Park announced that it would be closed through Wednesday because of rain, wind and snow that were forecast.

In Southern California, scattered showers with possible hail or graupel were expected to continue into the night, with most storms lightening up around Sunday morning. Sunday is expected to remain clear before another storm system moves in on Monday, according to the Weather Service.

In the mountains, the Weather Service forecast moderate snowfall of up to three inches more continuing into Sunday afternoon, keeping many mountain roadways impassable, as well as strong winds that could take down more trees.

Despite all the disruptions and inconveniences, some residents were not fazed.

“I love when all this stuff happens. I love all the rain we have been getting this year,” said John Carter, who was with his wife, Christina, at a Panera Bread in Corona, a town about 50 miles southeast of Los Angeles.

Mr. Carter, 46, a 911 dispatch operator for the Anaheim Police Department, said he loves the change and that he and his wife were looking forward to the spring poppies bloom, which was already happening in the hills along the highway near their home in unincorporated Riverside County.

Ms. Carter, 47, who works in administration with Southern California Edison, said the rain made all the foothills around them green, “and you get to see something different than your everyday dusty brown.”

Eduardo Medina, Mike Ives and Mark Abramson contributed reporting.