Widespread rain is expected Friday and Saturday in the Bay Area, National Weather Service officials said.

Rain is forecast to start Thursday night in the North Bay and spread south Friday, likely making the commute longer than expected.

Weather service officials said most of the rain will be light but heavier rain may fall Friday night and Saturday morning.

Most areas will get a quarter- to half-inch of rain, but the North Bay mountains could see an inch to an inch and a half while lower elevations may get half an inch to an inch.

A slight chance of rain exists for Sunday, according to the weather service.