Heavy rains snarled the morning rush hour Wednesday as a winter storm blows into Los Angeles County, bringing a renewed fear of flooding and mud flows to already saturated areas. However, there were no early reports of damage in areas at risk of mudslides.
Authorities were keeping a wary eye on Highland in San Bernardino County, where about 50 homes remained evacuated after last week's deluge caused mud to belch from local mountains, overwhelming a drain channel and inundating some homes with feet-deep ooze.
On Tuesday, about 700 shovel-toting volunteers took advantage of sunny weather to clear mud from around dozens of homes.
There was concern about debris basins meant to hold boulders, trees and muddy storm water swept down from the mountains.
"There's still 50,000-plus cubic yards of debris plugging them up. So we just don't know how a major rain coming off the mountainside would contain the debris," said Bill Peters, a spokesman for the California Department of Forestry and Fire Protection.
"We've been pumping water out of them since last Thursday, 24-7," he added. "They're down, but still, if we get a catastrophic debris flow like we got last week, it could get interesting."
The latest, fast-moving storm reached the area at about 3 a.m. after hitting Northern California on Tuesday night. Wind, gale and flood warnings were up through the morning from Fresno County southward.
The cold northern storm was expected to dump up to an inch of rain in four to five hours, followed by winds gusting to 75 mph in mountains and passes.
The rain and strong winds moved into the San Francisco Bay area during the Tuesday evening commute and caused arrival delays of more than two hours at San Francisco International Airport, the Federal Aviation Administration reported.
The National Weather Service warned that blowing snow and ice could make driving treacherous in the Grapevine area of Interstate 5, the main highway between Southern and Central California.
The same storm system prompted a blizzard warning through Thursday night for mountainous areas of eastern Arizona. The weather service predicted 14 to 25 inches above the 6,000-foot level with winds gusting to 60 mph Wednesday.
The storm was fueled by subtropical moisture from north of Hawaii, combined with low pressure over the Northeast Pacific. The previous storms were fed by a similar plume, but it originated from south of the Hawaiian Islands and rained most heavily in the southern half of the California.
The California Department of Transportation was still working to repair extensive damage to routes in the inland counties east of Los Angeles.
Among the worst damage sites was a section of State Route 330 that slid down a mountain, leaving a huge gap in the road that leads to resorts at Big Bear Lake in the San Bernardino Mountains. There was no estimate of how long it would take to restore the route, Caltrans said.
Forecasters said most of the rain would fall in a four- to six-hour period and would be followed by widespread, potentially damaging winds and with very cold temperatures Wednesday night through Thursday night.
Just after 5 a.m. Wednesday, the National Weather Service issued an urban and small stream flood advisory for Los Angeles County.
“At 5:05 a.m. Doppler radar and rain gauges indicated rain across the entire county,” the advisory states. “Widespread rainfall rates of one to three tenths of an inch per hour were occurring … with the highest rates across the San Gabriel Valley and foothills … just below the Station Fire burn area … Minor debris flow and rock slides are possible in and around the recent burn areas.”
Right around the same time, two lanes of the southbound Harbor (110) Freeway at Redondo Beach Boulevard were flooding or flooded, CHP Officer Anthony Martin says.
The slippery conditions contributed to slow traffic on the freeways and surface streets, as well as a number of traffic crashes.
Just before 5:45 a.m., a small black sport utility vehicle spun out on the southbound Hollywood (101) Freeway north of the Vermont Avenue exit.
The vehicle was stopped in the far left lane and facing the wrong direction, and it was just one of the rain-related mishaps Wednesday morning.
KPCC Wire services contributed to this story.
© 2010 The Associated Press.