It's welcome news for the state, which has just endured its driest year in recorded history.
While the rain won't be enough to end the drought, the National Weather Service projects that by Saturday, twin Pacific storms may bring as much as two inches of rain to the coast and several feet of snow to the Sierra.
The first storm is expected on Wednesday and will offer light rains.
But the storm on Friday is expected to drench the entire state for 24 hours.
Four consecutive years of drought, millions of dead trees and summer heat, are all factors as thousands of firefighters work to control wildfires in California.
Not much change is expected in drought conditions in California during the summer "dry season" but wildfire danger is increasing, with 66 million dead trees in the Sierra Nevada adding potential fuel.
The U.S. Forest Service says 66 million trees are dead in the Sierra Nevada after four consecutive years of drought in California and a bark beetle infestation.
California is in the fifth consecutive year of drought and water providers continue to urge voluntary conservation, as mandatory statewide rules have ended. Sacramento-area residents reduced their water use by 31 percent in May.
As thousands of federal and state firefighters work to contain wildfires in California and other western states, record-setting heat has prompted warnings from the National Weather Service for parts of California, Nevada and Arizona.