Until about five years ago, Tornado Alley consisted of a bull’s eye of tornado activity in parts of Texas, Oklahoma, Kansas, and Nebraska. But in years since, that hot spot of tornado activity has shifted east, into parts of the Deep South and the Tennessee Valley.
This eastward shift was noticed very early on by tornado expert Dr. Victor Gensini who published his study findings in the Journal of Climate and Atmospheric Science in 2018. Gensini had two theories as to why the eastward shift would take place: natural variability in which the tornado activity may eventually shift back west, or climate change, where activity may remain shifted east long-term.
In a recent study, researchers confirmed the eastward shift has taken place and is continuing.
There are several key findings from the study:
- Eastern Kansas, Oklahoma, and Texas saw a 40% reduction in tornadoes; Southern Mississippi saw a 25% increase in tornadoes
- The “bull’s eye” of tornadic activity previously was in south-central Oklahoma, but has now shifted to southern Mississippi
- A large zone from Texas to Nebraska experienced fewer tornado days, while Middle Tennessee, western Kentucky, and the Mid-Atlantic saw an increase in tornado days
- Tornado path lengths decreased over the Great Plains and increased in parts of the Midwest and Southeast
- Significant tornadoes (EF2-EF5) greatly decreased in the Great Plains and increased in the Deep South and Tennessee Valley
- May tornadoes have decreased, with cool-season tornadoes becoming more common (especially in the Midwest and Southeast from November to March)
The results of the study spell problems for residents of the Midwest and Southeast primarily because of the higher population density and greater prevalence of mobile homes.
Experts still are not sure why the tornadic activity has moved, and whether it’s associated with long-term atmospheric-ocean cycles, human-caused climate change, or something else. It is also unclear if this shift will reverse or become more pronounced, but if climate change is driving the changes, the shift will likely be long-lasting.
