Fragments of a green hull believed to be one of two sailboats missing from a wind-whipped yacht race were spotted yesterday on two beaches, the Coast Guard said.

Aircraft have been searching the choppy waters since fierce winds disrupted a race from here to the Farallon Islands on Saturday.

Spotter planes reported no sign of the four people aboard the Sweet Omega and the Bad Sneakers. But 10-foot-long pieces of a hull spotted at midday on two beaches were "almost assuredly" from the Sweet Omega, Coast Guard master chief Dave Cipra said.

On Sunday, a life ring, raft and life jacket from one of the boats was found floating off Point Reyes, but there was no sign of survivors.

An unexpected gale ambushed 127 boats in Saturday's annual race, capsizing one boat and forcing four others aground. It was the latest in a series of storms that have given Northern California its wettest winter in nearly a century.

Seven inches of rain and gale winds over the weekend caused mudslides and flooding and killed at least four persons--including two on another boat off San Francisco that was not involved in the race.

Between July 1, 1981, and Easter Sunday, 36.28 inches of rain fell in San Francisco, the most rain for the period since 1889-90 and considerably more than the 20.66 inches which is normal for the period. The city's record rainfall, 49.27 inches, occurred 120 years ago, the weather service said.

Meanwhile, meteorologists said snow deep enough to hide telephone poles in the mountains of California may not melt by the end of summer. The National Weather Service said most locations in the Sierra Nevada have 20 to 40 feet of snow on the ground.