Evacuation orders remained in effect for hundreds of homes in Los Angeles County foothill communities where fires have burned away vegetation that holds soil in place, and bursts of rain caused the mountains to belch occasional debris flows.
The storm marked a sharp departure from many months of drought that has grown to crisis proportions for the state's vast farming industry. However, such storms would have to become common to make serious inroads against the drought, weather forecasters have said.
Officials warned that despite lengthy lulls, more heavy downpours are expected, and they urged residents who left their homes as much as three days earlier to be patient.
"These mountains are now saturated and soaked. We know where the mud's gonna go, we just don't how much and what the intensity is going to be," Assistant Chief Steve Martin of the Los Angeles County Fire Department told a webcast news conference.
The National Weather Service said the storm is forecast to move east over the Rockies and into the Plains and Mississippi Valley through Sunday, bringing a hodgepodge of precipitation. Colorado's ski resorts could see up to 6 inches of fresh snow. A mixture of sleet and snow in Kansas, Missouri and Illinois will eventually change over to all snow - with up to 8 inches forecast for Kansas City and the St. Louis area - while northern Arkansas will see freezing rain. The system also has its sights set on the Appalachians and the East Coast into Monday.
The storm's eastward move on Saturday finally broke a 70-day streak without precipitation in the Phoenix area. An 85-day spell of no measureable rainfall in Las Vegas ended Friday. Rain and snow also finally came to drought-stricken New Mexico. In Denver, a highway pileup involving more than 100 vehicles killed one person and injured 30 others as heavy snow fell Saturday, authorities said.
In California, about 1,200 houses in the adjacent cities of Azusa and Glendora as well as nearby Monrovia have been under evacuation orders because of the possibility of destructive flows from the San Gabriel Mountains, a rugged range largely covered by the Angeles National Forest. A dozen homes in Azusa were in particular danger.
In Azusa, Jeff White told the Los Angeles Times that his home, across from the mountains, wasn't damaged. He'd returned Saturday to grab clothes and check on his neighbors. Homes had mud on their terraces and plants were covered in silt.
"We evacuated in January, we evacuated in February," said White, referring to the Colby fire in January that scarred 2,000 acres. "We're just hoping March will be better."
Glendora City Manager Chris Jeffers said experts planned to study the condition of slopes where rain had fallen at the rate of 1.3 inches an hour at times.
"Our hope is to get up closer to some of the hills for our engineers to see how the saturation may look, if there's any signs of stress on the hillsides, on any of the properties," he said.
Forecasters said the upper-level low at the storm's center would come ashore and move east through the day, dragging rain with it but leaving only showers in California on Sunday - a lucky break for the evening's Oscar red carpet festivities in Hollywood.
The storm was the much more powerful second act of two systems that hit California during the week.
Downtown San Francisco received 8 inches of rain by Saturday afternoon, bringing the city to 44 percent of its normal rainfall but avoiding the city's driest-ever "rain year" record by roughly half an inch, NWS meteorologist Matt Mehle said The driest year was in 1851, with just 7.42 inches. The rain year begins July 1.
"All this rain has been really helpful but we are still behind the curve in terms of the drought," Mehle said.
Downtown Los Angeles tallied 2.97 inches from the second storm by Saturday afternoon, said NWS weather specialist Bonnie Bartling. That raised the rainfall total to 5.16 inches since July 1, still 6.19 inches below normal.
Other trouble spots included about 13 homes that were evacuated Friday night in the Lake Hughes area in northern Los Angeles County after a mudslide closed a major road. To the east in San Bernardino County, a levee failed and put eight houses in danger of serious flooding, but county fire crews were working to protect them and no evacuations were ordered.
At the north end of Monterey Bay, a stretch of the oceanfront drive in Santa Cruz was shut down Saturday after a large sinkhole appeared in a cliff, opening the roof of a cave where homeless people have lived. Authorities said public works was investigating.
The storm was so volatile that a tornado warning was issued early Saturday for suburbs east of Los Angeles. A tornado warning was issued for Sacramento, Yolo and Sutter counties on Friday night but was canceled soon after.
Numerous traffic accidents occurred on slick or flooded roads across California, including one about 60 miles east of Los Angeles involving a big rig whose driver died after falling from a freeway overpass. The Fresno County sheriff's office also reported a man was injured by lightning Friday.
Utilities were working to repair numerous scattered power outages.