California: The US National Weather Service (NWS) is warning Californians to brace for "heavy lower-elevation rain, significant mountain snow, and strong winds," expected for Monday.
Late on Saturday, US President Joe Biden declared a major disaster in California after a succession of storm systems caused death and destruction across the state.
He ordered "federal aid to supplement state, tribal, and local recovery efforts in the areas affected by severe winter storms, flooding, landslides, and mudslides," the White House said.
Significant storm on Saturday
At least 19 people died in a series of storms that have caused havoc in California since late December.
A series of so-called atmospheric rivers has dumped rain and snow on California, cutting power to thousands, swamping roads, unleashing debris flows and triggering landslides.
"These weather events have taken more lives in the last two years than wildfires," California Governor Gavin Newsom said. "That's how deadly they are."
On Saturday, the first of two systems hit central California, unleashing more heavy rain.
It prompted emergency evacuations in parts of Santa Cruz, Monterey, San Benito and Sacramento counties.
More than 24,000 utility customers were without power as of Saturday afternoon, according to the website PowerOutage.us.
Next storm arrives Sunday night
"Another surge of Pacific moisture" is expected Sunday overnight into Monday, the NWS warned, while predicting "disastrous flooding" across the lower Salinas River valley, a key agricultural region south of San Francisco Bay.
The governor urged Californians to continue exercising "common sense." Dry days are in the forecast for California later in the week.