VORTEK LLC

TOP TWENTY TORNADO-PRONE STATES

January 3, 2008

By means of the Site Assessment of Tornado Threat (SATT) software, VorTek has just completed its annual compilation of the top twenty tornado-prone states based on the latest National Weather Service data for tornadic activity from 1950 through 2006. Mississippi again ranks number one as the most tornado-prone state. The top twenty states are as follows:
 

Rank

State

ACF (%)

Annual Disturbed Land Area (Acres) 

1

Mississippi

0.0479

14474

2

Arkansas

0.0446

14862

3

Oklahoma

0.0433

19049

4

Kansas

0.0426

22284

5

Nebraska

0.0408

19980

6

Indiana

0.0394

9049

7

Iowa

0.0362

12982

8

Alabama

0.0345

11202

9

Illinois

0.0294

10446

10

Tennessee

0.0287

7559

11

Wisconsin

0.0269

9348

12

Georgia

0.0225

8368

13

North Carolina

0.0186

5822

14

Louisiana

0.0184

5238

15

Ohio

0.0178

4667

16

Kentucky

0.0172

4367

17

Pennsylvania

0.0169

4859

18

Missouri

0.0148

6533

19

Minnesota

0.0142

7245

20

Michigan

0.0142

5193

 

The Annual Coverage Fraction (ACF) represents the average fraction of land annually disturbed by tornadoes within the boundaries of the state from 1950 through 2006. The annual disturbed land area can be obtained by multiplying the ACF by the area of the state.