Hundreds of rescuers are combing wreckage in Southern California for more than a dozen people missing after mudslides that have killed 17 people.
Another 28 injuries have been reported in Santa Barbara County following the deluge that overwhelmed an area scorched by wildfires last month.
More than 100 homes were destroyed, and another 300 have been damaged.
The death toll rose on Wednesday afternoon after two more bodies were found, he added.
More than 50 people have been rescued already but many places were still inaccessible. Several roads were closed, including the major Highway 101 which authorities say will not be reopened until Monday.
The first rain in months caused mudslides when it hit ground that had been burned by December's huge wildfires.
After a wildfire, burned vegetation and charred soil create a water repellent layer which blocks water absorption. Together with the loss of vegetation, this leads to an increased risk of mudslides and floods.
The US Coast Guard has sent "multiple airships to support rescue operations" and warned the public not to fly drones, otherwise the flights would be grounded.
This comes after a record-setting year of $306bn (£226bn) of weather and climate-related disaster costs in the United States, with 2017 the third warmest year on record, according to the US National Oceanic and Atmospheric Administration.
California has suffered severe drought in five out of six of the past years, reports BBC.