Winter storm furiously results in San Francisco's 1st tornado warning

A major ice storm created treacherous driving conditions across Iowa and eastern Nebraska this weekend and prompted temporary closures of Interstate 80 after numerous cars and trucks slid off the road. “Luckily some warmer air is moving in behind this to make it temporary,” said Dave Cousins, a meteorologist with the National Weather Service's office in Davenport, Iowa. Later Saturday a tornado touched down near a shopping mall in Scotts Valley, about 70 miles south of San Francisco, overturning cars and toppling trees and utility poles, the National Weather Service said. The storm toppled some trees onto cars and streets and damaged some roofs in San Francisco, which has not seen a tornado since 2005, according to the Weather Service. And in Nevada, up to 3 feet of snow was forecast for Sierra Nevada mountaintops, with a winter storm warning in effect through 10 p.m. More than a foot fell at some Lake Tahoe ski resorts, and a 112-mph gust of wind was recorded at the Mammoth Mountain resort south of Yosemite National Park, according to the National Weather Service’s Reno office.