A cold storm brought snow and rain to California on Tuesday and forecasters warned that freezing temperatures will follow.
A winter storm warning was posted in the northern Sierra Nevada and Caltrans urged motorists to check for chain controls on major routes.
Snowfall in Southern California mountains was expected down to elevations as low as 2,000 feet (610 meters), forecasters said.
The snow and rain is needed in California, where the wintry weather vital to the state's water supply has been spotty after a very wet December.
The National Weather Service said downtown San Francisco recorded 0.01 inch (0.03 centimeter) of rain Monday evening, ending a 44-day streak of zero precipitation.
Widespread freeze warnings were issued for overnight hours from early Wednesday to Friday morning.