New York City recently experienced a tornado warning which is pretty rare for city inhabitants generally and NYC residents in particular. As a Midwesterner, I am very used to tornado warnings, but interestingly, tornadoes rarely hit the St. Louis area.
Why do big cities seem to be (but not always) immune to tornadoes?
The answer is probability. The vast majority of the U.S. is undeveloped. According the EPA, only 5% of the U.S. is “developed” with about 3% being urban. And the land use in “tornado ally” in the Midwest and South is even less developed. Thus, most tornadoes strike areas other than developed and densely populated areas.
Here’s a map showing unpopulated areas.
Note, however, that urban land use is expanding at the rate of about 1 million acres per year. Thus, the chances of tornadoes hitting urban areas is increasing. The below charts are from a fascinating study titled “The Expanding Bulls-Eye Effect” out of Northern Illinois University.
But what’s the deal with trailer parks?
Developing meteorological evidence suggests tornados develop from the ground up and do not drop down out of a storm cloud. Maybe the dense development and hardscaping of cities are preventative factors.
No shit? That’s really interesting