Six backcountry skiers were found alive, and 10 others were still missing Tuesday after an avalanche in Northern California during a powerful winter storm moving through the state.Search and rescue crews were dispatched to the C astle Peak area, northwest of Lake Tahoe, after someone called 911 to report an avalanche with people buried.Ashley Quadros, a spokesperson with the Nevada County Sheriffs Office, said the six skiers located were still awaiting rescue. Quadros said the survivors were asked to shelter in place as best they can while search and rescue ski teams reach them.She said there are 46 emergency first responders trying to reach them.The group included four ski guides with 12 clients, Quadros said.The Nevada County Sheriffs Office received a 911 call at about 11:30 a.m. from someone reporting an avalanche with people buried, Quadros said.The sheriffs office, the sheriffs Search Rescue team and a crew with the California Department of Forestry and Fire Protection combed the area of Castle Peak, which is northwest of Lake Tahoe, Quadros said.California is being walloped this week by a powerful winter storm carrying treacherous thunderstorms, high winds and heavy snow in mountain areas.According to the Sierra Avalanche Center of the Tahoe National Forest based in Truckee, the area in the Central Sierra Nevada, including the Greater Lake Tahoe region, was facing high avalanche danger in the backcountry with large slides expected to occur Tuesday and into Wednesday.The dangerous conditions were caused by rapidly accumulating snowfall piling on already fragile snowpack layers coupled with gale-force winds.Several ski resorts around Lake Tahoe were fully or partially closed due to the extreme weather. The resorts along highways have avalanche mitigation programs and were not expected to be at as high of a risk as the backcountry where travel in, near, or below the avalanche terrain was strongly discouraged, the center said.Its particularly dangerous in the backcountry right now just because were at the height of the storm, said Brandon Schwartz, Tahoe National Forest lead avalanche forecaster at the center.Experts rely on people who witness an avalanche or its aftermath to know when and where an avalanche has occurred, Schwartz said.Castle Peak, a 9,110-foot (2,777-meter) peak in the Donner Summit area of the Sierra Nevada, is a popular backcountry skiing destination. In the nearby town of Soda Springs, at least 30 inches (76 centimeters) of snow had fallen in the last 24 hours, according to the Soda Springs Mountain Resort.Forecasters said the western slope of the Sierra Nevada in northern Shasta County including portions of Interstate 5 and parts of the states Pacific Coast Range could see up to 8 feet (2.4 meters) of snow before the storm moves through late Wednesday.The storm wreaked havoc on roadways spanning from Sonoma County to the Sierra Nevada. Traffic was halted temporarily in both directions on I-80 near the Nevada state line due to spinouts and crashes, the California Department of Transportation reported.In January, an avalanche in the region buried a snowmobiler in snow and killed him, authorities said. Each winter, 25 to 30 people die in avalanches in the U.S., according to the National Avalanche Center.AP Report by OLGA R. RODRIGUEZ and JULIE WATSON ...read more read less