An ambitious study of the unique characteristics of tornadoes in the southeast launches this week as scientists examine areas that aren’t often considered cyclone hot spots.
The so-called Dixie alley, which includes areas in Louisiana, Mississippi, Alabama, Arkansas and Tennessee, has more deaths on average per year than the more well-known tornado alley of the great plains where massive cyclones are often caught on camera.
Florida, which has the third highest number of tornadoes on average per year nationally, will also be included in the study as researchers examine how tropical storms and hurricanes spawn tornadoes.
The $5 million project, dubbed Vortex SE, comes following a tragic tornado outbreak last week that killed seven people along the Gulf Coast and in Virginia.
According to the Storm Prediction Center, Florida has experienced 28 tornadoes this year, which is nearly five times the normal average for January and February.
“The great plains from northern Texas through Nebraska has been the traditional tornado alley, but the southeast experiences a lot of tornadoes and greater risks because of the high population density,” said Kevin Knupp, a professor in the Department of Atmospheric Science at the University of Alabama in Huntsville.
Knupp is working with Vortex SE (southeast) to help organize research teams, including at least two that will go out Tuesday to track any tornadoes that spin up in a low pressure system that is pushing into the Ohio Valley.
“That’s a great location for the formation of intense storms that produce strong rotation,” Knupp said.
Florida averages 59 tornadoes per year on a measure from 1985 to 2014. That’s second only to Texas, which averages 140 tornadoes.
But Florida’s tornadoes are less likely to be killers. The 30-year annual average of tornado deaths in Florida is three. In Texas, four people are killed on average each year.
Alabama has the highest number of average annual deaths nationwide at 14.
“The tornadoes in the southeast tend to have longer paths than those in the Great Plains,” Knupp said.
Watch as a waterspout trashes semi in Tampa.
One theory on why tornadoes stay on the ground longer in the southeast is they are met with more friction from the landscape, such as trees and hills. Instead of acting to knock down storms, the interference may help keep them spinning.
James Elsner, a tornado expert and professor with Florida State University’s Department of Geography, said friction also plays a role in Florida’s storms when wind gets rotating when it moves off the water onto land.
“Florida being surrounded by the ocean, we have a lot of heat and moisture in the air. That’s usually fairly benign, but when you get winds aloft, the combination tens to fuel the thunderstorms and make them rotate,” Elsner said. “Tornadoes in Florida tend to happen during the night and there are more people, so it’s an area where there is more vulnerability.”