LOS ANGELES — A powerful storm slid south through California on Tuesday, drenching the drought-stricken state with desperately needed rain but also triggering rescue efforts on a swollen river and mandatory evacuations due to the threat of mudslides in some areas scarred by wildfires.

The National Weather Service reported remarkable rainfall in several parts of the state.

North of the Golden Gate Bridge, Mount Tamalpais accumulated more than 11 inches over 72 hours. By early Tuesday, nearly 7 inches of rain had fallen in one area of Santa Barbara County, northwest of L.A.

The powerful system is a so-called atmospheric river that sucks up moisture from Pacific Ocean and dumps it at lower elevations as rain and in the mountains as snow.

The storm began over the weekend in Northern California and has brought heavy precipitation as far inland as Nevada, where more than 6 feet of snow fell since Sunday night at the Mt. Rose ski resort just southwest of Reno and more than 4 feet fell at Heavenly on Lake Tahoe’s south shore.

A second storm predicted to hit California midweek shortly after the current system moves on could deliver almost continuous snow in mountainous areas, said Edan Weishahn of the weather service in Reno, which monitors an area straddling the Nevada state line.