This paper offers an empirical test of the impact of human ecological
patterns and other known correlates on tornado occurrence. It uses the
National Severe Storms Forecast Center's information on tornadoes fro
m 1950 through 1990 and employs ecological data from the U.S. Bureau o
f the Census and the Environmental Protection Agency. The results show
that metropolitan and other urban counties have higher odds of tornad
o occurrence than rural counties, and that the probability of occurren
ce of tornadoes increases with increases in the number of previous tor
nadoes. The paper assesses the meaning of this finding for demographer
s, atmospheric scientists, engineers, and disaster managers.