An interesting map, really. Consider “Tornado Alley.” Where do you think Tornado Alley falls? Now, look at this map, and tell me where, according the tornado tracks, Tornado Alley can be found.
The perceptual region, Tornado Alley, is not particularly evident. In fact, I might argue that, based on this map, Tornado Alley is a myth.
Before I actually go there, though, a few considerations come to mind. First, the colors of the tornado tracks are problematic. Our eyes are very sensitive to the red, more so than the yellow, giving the map an appearance that mid-part of our nation is covered violent tornados. In fact, the map does seem to indicate a high degree of violent tornadoes. The Great Plains seems to have not only many violent tornadoes but also a great number of weak tornadoes.
Some spatial queries might help highlight Tornado Alley. Knowing the concentration of tornadoes per some unit of area would be interesting to know. Knowing the ration of weak vs. violent tornadoes per unit of area would also be interesting to know, as well.