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

LOS ANGELES — As rare blizzard conditions continued to present hazards in the mountains of Southern California on Saturday, residents at lower elevations braced for 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 debris flow and mudslides.

Multiple water rescues have been 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 was injured after intense 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, though flood advisories remained in effect in parts of Los Angeles and Ventura County throughout the morning.

And portions of Interstate 5 winding through Los Angeles County — including the Grapevine, a 40-mile stretch that goes up to Kern County — remained closed Saturday morning because of a mix of flooding, snow and mudslides.

More than 24,000 electricity customers in the Los Angeles region were also without power on Saturday, according to Southern California Edison.

“The greatest impacts over the lowest elevations are slowly winding down, although there is still some flooding,” Mr. Cohen said. On-and-off rain showers are expected to continue throughout the day, with temperatures remaining in the mid-40s.

In the mountains around Los Angeles, home to the popular Big Bear Lake ski resorts, blizzard warnings remained in effect. More than four feet of snow has already accumulated, and the total could double, with whiteout conditions on roads.

The storm has already set records. Earlier this week, Los Angeles County issued its first blizzard warning since Feb. 4, 1989. And on Friday, Los Angeles International Airport saw a record 2.04 inches of rain.

“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.

Eduardo Medina and Mike Ives contributed reporting.