Widespread rain will fall through midday Wednesday mainly south of San Francisco, according to the National Weather Service.
Minimal impacts are expected but another system will arrive Friday and move north to south through the San Francisco and Monterey bay areas.
Breezy to locally gusty winds and widespread rain are expected.
Lighter rain and the possibility of thunderstorms are expected late Friday into at least Saturday night.
The exact timing and impacts of the late-week system will be more certain in the next couple of days.