LOS ANGELES — Powerful thunderstorms raged throughout California on Monday, walloping the Sierra Nevadas with blizzard conditions and briefly knocking out power at the Los Angeles airport.

Some San Francisco Bay Area roads were under more than a foot of water during the morning commute. Santa Cruz and Santa Clara counties saw about 11 inches of rain over 72 hours.

Commuter traffic also slowed to a crawl on Los Angeles-area freeways as cars were pelted by hail and motorists struggled to see roadways and navigate flooded lanes.

Douglas Barkley said he was driving on State Route 91 when he saw a bolt of lightning that ignited a pair of palm trees along the freeway.

‘‘Embers were flying in the wind along with the rain,’’ he said.

Dozens of arrivals and departures were delayed but only a few flights were canceled after a storm briefly knocked out power at all terminals at Los Angeles International Airport. Backup systems kicked in and full power was restored within an hour, airport spokeswoman Nancy Castles said.

The rain could strike a blow against the ongoing California drought. As much as 20 inches was expected this week in some parts of Northern California amid a deepening snowpack that provides water to the state when it melts in the spring.

The storms arrived as the ocean-warming phenomenon called El Nino persists in the Pacific.

In the Sierra Nevada, a blizzard forced authorities to close Interstate 80 at Donner Summit for several hours overnight. Forecasters warned of whiteout conditions as up to 2 inches of snow fell each hour.

Strong winds knocked down trees and power lines across Southern California. Several vehicles were crushed by falling trees at a Central Coast RV park. No injuries were reported.

Snow fell in the mountains, bringing a welcome sight at ski resorts around the state. Sugar Bowl ski resort near Lake Tahoe saw 33 inches of snow at the summit overnight, said National Weather Service meteorologist Brian O’Hara.

Snow was expected at the 5,000-foot level in the mountains of Los Angeles and San Bernardino counties. Drivers on mountain passes, including the Grapevine section of Interstate 5, were cautioned about possibly icy conditions.

Associated Press

Over the weekend, Chia Xiong, 51, of Marysville died in Yuba County after being trapped in a car that became submerged in flood water on a highway.

The driver, who was able to get out of the car, was arrested for investigation of driving under the influence and vehicular manslaughter, California Highway Patrol Officer Jodie Beck said.