This distribution of tornadoes often feeds into the myth that mountains protect communities from tornadoes. In fact, the more rugged terrain of the mountainous region does not disrupt tornado tracks or prevent formation of tornadoes; however, the slightly cooler and drier climate leads to conditions less conducive to formation. In other words, the relative lack of tornado touchdowns in mountainous regions is because of the weather, not the terrain.Via Paul Douglas' On Weather blog.
26 April 2011
60 years of tornado touchdowns
tornado watches over a ten-year period. Here's an even-longer-range perspective: