FAYETTEVILLE, Ark. (AP) -- New research from the University of Arkansas finds that tornadoes cause greater damage when traveling uphill -- and that the twisters tend to climb toward higher elevations rather than going downhill.
Engineering researchers studied images of the 2011 deadly tornadoes in Tuscaloosa, Ala., and Joplin, Mo. The research team found similarities between the two tornadoes and say the findings likely apply to all tornadoes.
Researchers also found that when a region is surrounded by hills, tornadoes skip or hop over the valleys below. Damage is noticed only on the top of the hills.
The EF4 tornado in Tuscaloosa killed 64 people, while the EF5 Joplin twister killed 158 people.
The research was conducted by civil engineering professor Panneer Selvam and civil engineering graduate student Nawfal Ahmed.