Science / Weather / Tornado: A violently rotating column of air in contact with and extending between a convective cloud and the surface of the earth. It is the most destructive of all storm-scale atmospheric phenomena. They can occur anywhere in the world given the right conditions, but are most frequent in the United States in an area bounded by the Rockies on the west and the Appalachians in the east.
Science / Weather / Multiple Vortex Tornado: A tornado which has two or more condensation funnels or debris clouds, often rotating around a common center. MORE
Science / Weather / Tornado Alley: A geographic corridor in the United States which stretches north from Texas to Nebraska and Iowa. In terms of sheer numbers, this section of the United States receives more tornadoes than any other. MORE