A monster storm that triggered severe flooding in Southern California appeared to be easing Wednesday, leaving behind saturated mountainsides that could be at risk of mudslides for weeks to come.
Los Angeles was largely spared, but other parts of the state were pounded as the storm system moved east toward Arizona, Utah and Nevada. In California, hundreds of homes were evacuated in at-risk areas, and Gov. Arnold Schwarzenegger declared a state of emergency in six waterlogged counties.
Fire officials issued evacuation orders for 200 additional homes on a bluff in the San Bernardino County city of Highland. Bill Peters of the California Department of Forestry and Fire Protection says officials were very concerned about the stability of the bluffs on the east side of a wash.
Earlier, about 20 homes were swamped with 3 feet of mud, dozens of cars were buried and a bridge was badly damaged, when two creeks overflowed.
Flooding also closed the Corona airport in neighboring Riverside County, where some small planes had water up to their wings.
Peters says 90 people have checked in at a Red Cross evacuation center.
NWS forecaster Bob Oravec said the heavy rain, which began falling late Tuesday, could cause major problems "especially in those areas where they've had recent fires over the past few years. In addition to the heavy rain threat and flash-flood threat, we have the threat of mudslides in those areas."
Officials said that threat could continue for weeks in areas that have been denuded of forest by summer wildfires.
San Diego Fire-Rescue Department spokesman Maurice Luque said lifeguards used inflatable boats to rescue 47 guests and four employees from the Premier Inn in the city's Mission Valley area Wednesday.
Rains flooded the hotel's first floor, forcing guests to the second floor as they waited for help. Water moved quickly through the outdoor parking lot.
A rain-soaked hillside collapsed on part of a busy Interstate 10 transition road as overwhelmed drains left hubcap-deep pools of water on roadways littered with fender-bender crashes. The landslide covered three lanes of the transition to State Route 57 in the Pomona area, and the California Highway Patrol shut down part of the ramp before the Wednesday morning rush hour.
Storm runoff and mud prompted about 30 people to evacuate their homes in Orange County's Silverado Canyon. Authorities also said downtown Laguna Beach was closed Wednesday morning by up to 4 feet of storm runoff, which receded but left streets awash in mud.
A day before the latest storm, officials ordered the evacuation of 232 homes in La Canada Flintridge and La Crescenta, foothill suburbs of Los Angeles below steep hillsides that burned in 2009 and where mudslides inundated homes and backyards in February.
Walt Kalepsch, whose backyard filled with mud and debris last winter, said he would hoped to stay despite the evacuation order.
"If it gets really terrible, we'll leave. But we've been evacuated so many times, it's like the city's crying wolf," he said. "During the rest of the year, it's absolutely gorgeous. It was just one big wildfire that changed everything."
The huge and powerful low-pressure system off the West Coast pushed precipitation right into the Great Basin.
"It takes a lot of energy to push that moisture over the mountains," said NWS meteorologist Dave Bruno. "This kind of storm could march right across the country and create a lot of bad weather along the way. It could affect the Southern Plains on Thursday and Friday. If it sticks together it'll hit Florida by Saturday."
Wednesday's storm was the result of a collision between a powerful and cold storm from the Gulf of Alaska colliding with a river of subtropical moisture known as the "Pineapple Express" from the western Pacific Ocean.
"When you get the very cold air mixing in with the very warm air, it can be quite volatile," Bill Patzert, a climatologist at the Jet Propulsion Laboratory in La Canada Flintridge, told The Los Angeles Times, adding that Wednesday's storm was "definitely going to be the main event."
Rescuers had to pluck some stranded motorists from rain-swollen creeks. Shoppers dodged puddles while buying last-minute Christmas gifts. Disney resorts canceled a plan to shower visitors with artificial snow.
In Orange County, four hikers missing overnight in a flooded canyon in the Cleveland National Forest were rescued Tuesday morning by helicopter after their car was trapped along swollen Trabuco Creek. Rescuers used a bulldozer to retrieve five other people who became stranded by the creek.
Downtown Los Angeles received more than a third of its annual average rainfall in less than a week.
Parts of the San Gabriel Mountains got more than 18 inches of rain since Friday, with coastal cities like Santa Monica and Long Beach getting more than 6 inches, the National Weather Service said.
With rain falling up and down the state, Sierra Nevada ski resorts enjoyed record-breaking December snowfall, with the storms bringing more than 15 feet of flakes to Mammoth Mountain.
For all the perils of the torrential rains, there was a silver lining: The water is expected to help ease the effects of years of drought. Skies were expected to clear Thursday, though light rain was forecast on Christmas Day in parts of California.
Water content in the snowpack in California's mountains was at 197 percent of normal and 169 percent of the average measurement for April 1 -- traditionally the date when the snow's water content is at its peak, said Ted Thomas, spokesman for the California Department of Water Resources.
As the snow melts, that water will run off into reservoirs that feed the state's extensive agriculture and city water systems.
Material from The Associated Press was used in this report
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