What is Tornado Alley?
The term “Tornado Alley” was first used by a United States Air Force meteorologist and an Air Force captain as the title of a research project. Nowadays, the term is mostly used by the media and through other news outlets. We’ve all heard of Tornado Alley, but what exactly does it mean? We all know that it describes a region that is susceptible to tornado damage, but what specifically makes up this region, and why is this region affected? Even the National Weather Service has yet to issue a specific region that defines Tornado Alley. To get a more specific grasp on this region, and because of my interest in meteorology, I decided to do a little research.
One useful article by Smith Kendall says that Tornado Alley includes the area in the south-central United States where there is a higher frequency of tornados. Specifically, it explains that Tornado Alley runs from central Texas to northern Iowa, and from central Kansas and Nebraska to western Ohio. Given these bounds, it is no surprise that Texas, because it is such a large state, reports the most tornados of any state. The smaller states of Kansas and Oklahoma have the most reported tornados per unit area of measurement.
Regarding meteorology, the article explained that Tornado Alley is ideally situated for the formation of supercell thunderstorms. Supercells are types of thunderstorms that have a rotating small-scale current of rising air. This current of air is often found in a cloud. Because of this rotating air, supercells are sometimes called rotating thunderstorms. Basically, if you look up in the sky and see a large or small thunderstorm cloud spinning, there is a good chance that it is a supercell. Supercells can be very severe, and they have the propensity to ultimately create tornados.
In essence, it seems that Tornado Alley, while it does not have any set criteria for defining the region, is characterized by the increased frequency of tornados that form in the region. One study found that about a quarter of all significant cyclones occur in this area. What is it about Tornado Alley that leads to all of these tornadoes? Well, in my research I found that in this region, warm, humid air from the equator clashes with the cold, dry air from Canada and the Rocky Mountains. This creates an ideal environment for supercell formation, and therefore ultimately tornado formation.
Given these ideal temperatures and air conditions, it is no surprise that because of Tornado Alley, the United States has more tornados than any other nation. The nation with the next highest tornado frequency is Canada.
The next time you hear the phrase Tornado Alley, you should now have a better understanding what the phrase is referring to. While there is no set definition, the area is largely defined by the weather conditions that create supercells, and ultimately tornados. Next time you’re in Tornado Alley, watch out for spinning clouds!