A Supposedly Fun Thing I'll Never Do Again: Essays and Arguments by David Foster Wallace:
Still strangely eager to speak of weather, let me say that my township, in fact all of East-Central Illinois, is a proud part of what meteorologists call Tornado Alley. Incidence of tornadoes all out of statistical proportion. I personally have seen two on the ground and five aloft, trying to assemble. Aloft tornadoes are gray-white, more like convulsions in the thunderclouds themselves than separate or protruding from them. Ground tornadoes are black only because of the tons of soil they suck in and spin around. The grotesque frequency of tornadoes around my township is, I’m told, a function of the same variable that cause our civilian winds: we are a coordinate where fronts and air masses converge. Most days from late March to June there are Tornado Watches somewhere in our TV stations’ viewing area (the stations put a little graphic at the screen’s upper right, like a pair of binoculars for a Watch and the Tarot deck’s Tower card for a Warning, or something). Watches mean conditions are right and so on and so forth, which, big deal. It’s only the rarer Tornado Warnings, which require a confirmed sighting by somebody with reliable sobriety, that make the Civil Defense sirens go. The siren on top of the Philo Middle School was a different pitch and cycle from the one off in the south part of Urbana, and the two used to weave in and out of each other in a godawful threnody. When the sirens blew, the native families went to their canning cellars or fallout shelters (no kidding); the academic families in their bright prefab houses with new lawns and foundations of flat slab went with whatever good-luck tokens they could lay hands on to the very most central point on the ground floor after opening every single window to thwart implosion from precipitous pressure drops. For my family, the very most central point was a hallway between my dad’s study and a linen closet, with a reproduction of a Flemish annunciation scene on one wall and a bronze Aztec sunburst hanging with guillotinic mass on the other; I always tried to maneuver my sister under the sunburst.