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.
The U.S. Drought Center says the past week brought "widespread improvements" in drought conditions in northern California and Nevada.
California's energy grid manager says supply should be adequate for the summer, despite potential natural gas shortages in Southern California.
California water regulators will allow cities and water agencies to set their own conservation targets based on water supply.
Fire agencies are expected to continue prescribed burn operations this week in the Lake Tahoe Basin.
Severe and extreme drought were reduced slightly in California and 10 percent of the state is completely free of drought.