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.
Mandatory statewide water conservation rules have ended in California. But Sacramento-area users conserved 22 percent in June, compared to June 2013.
California and federal agencies say a new strategy is needed to save the endangered Delta smelt.
California is in the fifth consecutive year of drought, but state water managers ended mandatory conservation rules. Local water suppliers now determine conservation rates, and some have low or no targets. A water expert says that's 'shortsighted.'
California is in the fifth consecutive year of drought. Although mandatory statewide water conservation is over, the State Water Resources Control Board says water conservation remains a "top priority."
The California Water Resources Control Board Wednesday says Californians cut water use by 28 percent in the final month of mandatory statewide conservation.