A widespread downpour is headed to the Bay Area early Saturday morning, leaving the region with moderate amounts of precipitation according to the National Weather Service.

The storm, which was forecast to cover an area from the Pacific Northwest to California’s Central Coast, is expected to roll in to the Bay Area around 4 a.m. Saturday with the bulk of the rainfall occurring in the daylight hours.

The widespread storm was predicted to cover the entire region, though totals may vary due to rain shadowing, an effect where mountains act as a shield to heavier rain to valleys because precipitation must rise above them.

Expected rain totals on Saturday include as much as an inch of rain in San Francisco, Oakland, Santa Cruz and Concord. About one-half of an inch was predicted in San Jose and Livermore — two rain-shadowed areas.

The region should experience steady rainfall until about 10 p.m. Saturday, according to the NWS.

Source: www.mercurynews.com