A new study by researchers at the University of Georgia could explain how drought conditions in the fall and winter may affect tornado activity the following spring.

Though the study is specific to the Southeast, Marshall Shepherd, associate professor of geography and atmospheric sciences, hopes further research could reveal patterns elsewhere in the country.

Shepherd said he got the idea for the study after a tornado hit Atlanta in 2008.

"It really was stimulated by the tornado that hit downtown Atlanta," Shepherd said. "That was such a rare event in itself, I started asking the question. At that time, we were in the midst of one of the most severe droughts on record. I just posed the question, ‘Gee, how rare were tornadoes under drought conditions?’"

Shepherd said he looked to see what research had been done on the topic but didn’t come up with anything substantial, so he was excited to find a high correlation between drought and tornado activity.

"We were extremely surprised," Shepherd said. "When we looked closer and looked at all of the years when there was drought in the previous fall and winter we found that 93 percent of the time when there was drought in the fall and winter the following spring had below normal tornadoes, and that was shocking."

Shepherd said he plans to do further research on the subject to determine if the information might have practical uses in the future.

"If that holds in other areas, then that might give us some degree of predictability of seasonal tornado activity many months in advance. It’s too early to start saying that with certainty, but that’s certainly what the implications of this research are," he said.

Now that a connection has been established, Shepherd hopes to learn why drought and tornado activity are related.

"We have a hypothesis that it’s related to something called soil moisture memory, which is if the soil’s dry, that actually affects the atmosphere as you move into spring," he said.

Ultimately, Shepherd would like to look at the possibility of seasonal predictability, "in the same way forecasters look at the rain that falls in Africa in the fall and use that information to predict how active the Atlantic hurricane season is going to be," Shepherd said.

Being able to predict how busy tornado season may be likely could interest many in Gainesville, which has a long history of tornadoes.

Glen Kyle, the managing director of the Northeast Georgia History Center, said one of the most severe tornadoes in history tore through downtown Gainesville in 1936.

The tornado caused wind damage and sparked a number of fires, causing major damage to the area that took nearly two years to rebuild.

Many factory workers died because they were locked in their building when the tornado hit.

"This tornado changed building codes nationally," Kyle said.

Other major tornadoes hit Hall County in the early 1900s and again in 1998. The 1998 tornado resulted in additional warning sirens being installed across the county. The most recent tornadoes to hit Hall County struck on Aug. 26, when three minor tornadoes damaged two schools and several homes.

"We’re sort of sitting in a tornado-prone area," Kyle said.