LOS ANGELES (AP) — Authorities rescued one driver early Thursday but were unable to save two more from a submerged car in a flooded underpass south of San Francisco.

Meanwhile, residents of several Southern California mountain and canyon communities were urged to voluntarily leave their homes because of possible mud and debris flows from potentially heavy rain starting late Thursday. The evacuation warnings are posted in parts of Orange and San Bernardino counties.

The National Weather Service has issued advisories for minor flooding in counties around San Francisco Bay. An avalanche warning has been issued for eastern Sierra Nevada backcountry areas in Mono and Inyo counties.