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.
There was a slight reduction in the percentage of drought in California over the past week. But the U.S. Drought Monitor says it will take time to ease the state's historic four-year drought.
A new study says California's four-year drought has reduced hydroelectricity generation, resulting in higher electricity costs to ratepayers and increased greenhouse gas pollution.
Legislation introduced in the California state Assembly would create the Lower American River Conservancy to improve, protect, preserve and possibly expand the 5,000-acre American River Parkway.
January brought above-average rainfall and snow to much of California, partly due to El Niño. But forecasters say the ocean warming condition is "taking a break" for the next week or longer.
The U.S. Drought Monitor says, other than a slight reduction in exceptional drought in the northern Sierra, it needs more time to assess impacts of the recent moisture on California's long-term drought.