( CNN ) -- A huge winter storm was affecting the West Coast on Sunday , poised to dump up to 10 feet of snow in some higher elevations , and causing flooding and potential mudslides in lower spots while impacting driving conditions and air travel , forecasters said . A winter storm warning remained in effect through Monday afternoon for California 's Sierra Nevada mountains , from Yosemite to Kings Canyon , according to the National Weather Service . `` Storm totals of 5 to 10 feet above 7,000 feet are likely , '' the weather service said , and periods of heavy snow will continue through Monday . High winds are also forecast for the region . `` Travel into the high country of the southern Sierra Nevada may be difficult , if not impossible , '' according to forecasters . That possibility exists for the northern Sierras as well . At 3:56 p.m. PST , the National Weather Service was predicting blizzard conditions with winds of up to 70 mph along the higher mountain passes . That could shut down traffic along Interstate 80 , state Highway 50 and state Highway 88 . The Weather Service was urging residents in the higher mountain areas to check their generators and buy extra food and supplies . `` It 's going to be an all-day onslaught , '' said CNN Meteorologist Reynolds Wolf . Areas from Denver westward will see rain , he said . At lower elevations , heavy rain was causing flash flooding in a number of locations . Flood advisories and watches were posted almost the entire length of California , from Redding to San Diego . Los Angeles had received 2 to 3 inches of rain as of about 2:30 a.m. Sunday ( 5:30 a.m . ET ) , and `` more significant rain '' was on the way , forecasters said . Flooding in the San Joaquin valley , which includes Fresno and Sacramento , is a `` firm possibility , '' said Wolf . Footage from Sacramento showed drivers creeping through water on roadways . As of Sunday afternoon , the California Emergency Management Agency was reporting localized flooding across the state , prompting road closings in San Luis Obispo , Fresno , Tulare , Amador , Venture County , Kern County and Humboldt County . And with the heavy rain comes the threat of mudslides , especially in areas near Los Angeles affected by this year 's wildfires , where there is no vegetation to hold the soil in place , Wolf said . The soil becomes saturated and gravity pulls it downward . `` Some minor debris and rock slides have already been reported early this morning , '' said a southern California flood advisory issued by the National Weather Service , `` and this threat will likely continue through this morning . '' The threat could also be delayed , meaning it will not abate when the rains stop and could occur later , Wolf said . In Placer County a minor mudslide forced the closing of one of two lanes on Interstate 80 on Sunday . The storm -- actually a series of storms -- were triggered by `` deep persistent moisture '' originating from the subtropical Pacific and surging northeastward , said CNN Meteorologist Sean Morris . The phenomenon is often called the `` Pineapple Express , '' he said , because the moisture originates near the Hawaiian islands . The series will affect the region through Wednesday , with the strongest portions yet to come , Morris said Saturday . Rainfall amounts could reach 10 to 12 inches in some spots , and up to 18 inches in some isolated areas , he said . The storms could be the strongest to hit southern California since January 2005 , he said , when up to 32 inches of rain came in a five-day period . On Saturday , there were more than 260 freeway crashes in Los Angeles County and unincorporated areas because of the rain , said California Highway Patrol Officer Ed Jacobs . That is compared to 48 last Saturday , when it was not raining , he said . Most of the crashes were `` minor fender benders , '' he said , but two people died in a crash in Santa Clarita . `` We think the driver was just going too fast in that case , '' he said . About 5,000 customers lost power in southern California , said Steve Conroy of Southern California Edison , but noted that is a small percentage of the company 's 5.4 million customers . The biggest problem the company faced on Saturday was drivers traveling too fast and sliding into poles , causing some service interruptions , Conroy said . The company serves some of the mountain areas , and have crews in place there , he said . `` Overall , we 're in good shape . '' About 2,100 customers lost power early Sunday in the Highland Park area of Los Angeles , but power had been restored as of about 6:30 Sunday morning , said Maychelle Yee , spokeswoman for the Los Angeles Department of Water and Power . The outages were likely weather related , she said . Further north , high winds affected Seattle , downing trees and power lines , and knocking out power to about 100,000 people . Most of those had been restored as of Sunday . Footage from Spokane , Washington , showed drivers crashing as they slid down a snowy hill . Besides the potential for road closures , air travel could be affected in cities including San Francisco ; Los Angeles ; Seattle ; Portland , Oregon ; and Salt Lake City , Wolf said . Those delays could have a ripple effect elsewhere as a busy holiday travel week approaches . CNN 's Nick Valencia contributed to this report .
National Weather Service warns of 70 mph blizzard in northern Sierra Nevadas . NEW Minor mudslide ##s down portion of highway in Placer County , California . Up to 10 inches of snow is possible in the Sierra Nevadas . Lower elevations will see up to 18 inches of snow .