Storms encase Iowa and eastern Nebraska in ice and generate rare tornado warning in San Francisco

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. Many events were canceled across the region when the storm his Friday evening and businesses announced plans to open late Saturday as officials urged people to stay home if possible, but temperatures are expected to rise high enough in the afternoon to melt the ice in most places. Elsewhere, a storm prompted the first ever tornado warning in San Francisco and caused some damage. And in the Northeast, people are digging out after heavy snow fell in upstate New York.