Four Active Tornado Regions Defined: Dixie Alley, Tornado Alley, Hoosier Alley and Carolina Alley

According to Frates, who recently graduated with a master’s degree from the UA Department of Geography and Planning, Tornado Alley really ecompasses four regions, not exclusively the area between the Rocky and Appalachian mountains as traditionally described.

Frates presented his findings at the American Association of Geographers annual meeting in Washington, D.C. last month. Ever since, the looming winds of change reveal that Dixie Alley, Tornado Alley, Hoosier Alley and Carolina Alley collectively, represent a true Tornado Alley.

In his study of the spatial distribution of dangerous tornadoes — ranked F3, F4 or F5 — according to intensity, Frates discovered that such tornadoes occur most often in Dixie Alley, which spans from eastern Texas across parts of Missouri, Arkansas, Louisiana, Mississippi, Tennessee and Alabama into northeast Georgia. Tornado Alley, an area of the Central United States that experiences a high frequency of tornadoes, follows closely behind.

Image credit: Michael Frates/University of Akron

Frates examined the distribution of tornadoes with tracks greater than 20 miles, which occurred between 1950 and 2006 over the geographic area incorporating all four regions. Frates reviewed this entire area as a grid of 3,068 cells, each representing 1,082 square miles. By studying these area units of equivalent dimension, Frates was able to study the area as a whole divided into equal parts — not as individual regions of varying size marked by traditional boundaries such as county and state lines — and ultimately, present these breakthrough findings.

Source: University of Akron