https://www.mercurynews.com/2021/12/12/storm-tracker-map-how-much-bay-area-rain-is-still-to-come/

The first showers in what is expected to be a two-day storm arrived in the Bay Area in the early hours of Sunday.

Widespread rain is forecast to start on Sunday afternoon and continue into Tuesday morning. After a respite Tuesday, a second wave is expected to arrive Wednesday night.