A storm left up to two feet of snow in the mountains of the West yesterday after hammering California's coast with 12-foot waves that destroyed a restaurant, washed away part of a hotel and damaged beach homes.

Officials said seven people died in California as a result of the storm before it set off on a track expected to send it over the Central Plains by today.

More than 20 inches of snow fell at Monticello in southern Utah, with 18.8 inches at Durango, Colo., and 17 inches at Flagstaff, Ariz., the National Weather Service said. Up to two feet of snow fell in northern California.

The heart of the storm was a low pressure system that sent barometers plunging to a reading of 29.25, the lowest level measured at Los Angeles in 100 years of record-keeping, forecasters said. It created breakers up to 14 feet at Los Angeles that coincided with a 7-foot high tide yesterday morning. A 1912 Mark Is Broken

The barometer dropped to 29.25 inches at 5:48 P.M. Sunday and stayed there for 19 minutes. The previous record of 29.26 inches was set in March 1912.

"It was a very strong storm and it went right over the top of us," John Henderson, a weather service meteorologist, said of the Sunday tempest, which generated a relatively light total of 1.33 inches of rain in 24 hours.

Rain-filled storms that come ashore in southern California have what meteorologists call a "long fetch" of eastward movement over warm ocean waters. But Sunday's storm swooped southeastward along the coast at about 48 miles an hour and had little chance to pick up moisture, Mr. Henderson said.

Santa Maria, near the Central California coast, had only .72 inches of rain in 24 hours to go with its bottom-seeking barometer. Fog Blankets Chicago

Dense fog kept airliners from landing or taking off from Chicago's O'Hare airport yesterday morning, and at least one person was killed when a private jet crashed in dense fog near Houston's Hobby Airport, the authorities said.

Snow kept students from reaching class in some rural areas outside Flagstaff and in parts of southwestern Colorado and central Utah. Schools closed at Durango, Colo., because of snow for the first time in 20 years.

About 100 vehicles were briefly stranded on a snow-clogged mountain pass in the Tehachapi Mountains in southern California. Snow closed Interstate 5 Sunday and yesterday at Grapevine, in the mountains about 60 miles north of Los Angeles, the California Highway Patrol said.

Although the sky over the coast cleared to brilliant blue yesterday after the storm rolled inland, the San Diego Zoo failed to open for the first time in its 72 years. High wind had toppled a dozen towering trees and threatened to fell others, a zoo spokesman said.

Los Angeles County officials closed all piers and reported flooding at most beaches. Mayor Tim Casey of Redondo Beach declared a local state of emergency. Part of Hotel Collapses

Waves caused at least 10 injuries and threatened to sweep two Redondo Beach police officers to sea, although they were rescued immediately.

The south end of the three-level Portofino Inn at Redondo Beach collapsed into the surf Sunday night and continued crumbling yesterday, said Carolyn Franck, a spokeswoman for the city fire department. More than 100 guests fled, including about 50 who were evacuated from the hotel's top floor by a helicopter owned by the radio station KNX.

Among beachfront houses damaged at Malibu was one belonging to the singer Joni Mitchell, which is for up sale for $3 million, witnesses said.

"I've seen some boats floating by," said Larry Hagman, the star of the television series "Dallas" who is a longtime resident of the exclusive Malibu Colony on the coast northwest of Los Angeles. "I just saw my neighbor's deck float by a minute ago," Mr. Hagman said. His neighbor is the comedian Don Rickles.

The storm-related deaths included two men and a woman found in a car buried by an avalanche in the Angeles National Forest about 30 miles northeast of Los Angeles. And four people died when a light plane crashed in rain and fog 30 miles northwest of Los Angeles, officials said.