A rare blizzard has been causing all sorts of problems in the northwestern United States.  After its start in Alaska, it slid down south and east into Washington and Utah with snow, icy rain, blustery wind, and extreme cold.  Early this morning, Sea-Tac Airport recorded a temperature of 14 degrees, a 25-year low.  Several city transit buses crashed in Seattle, and one overturned.  The storm front then moved on to Utah and Wyoming, where a 40-mile stretch of Interstate 80 was closed because of white-out conditions causing tractor-trailer jackknifes.  A large section of Interstate 15 in Utah was shut down under similar conditions.  The blizzard is now moving into Colorado and New Mexico, and travelers in northern Arizona are being warned of possible road closings.  Conditions are causing mixed feelings in the local ski areas because conditions are great for skiing, but most people can't reach the resorts because of road closures.