V
ORTEK LLCApril 29, 2009
As part of an ongoing company-funded research study of tornadic risk assessment, by means of the Site Assessment of Tornado Threat (SATT) software*, VorTek has determined the rankings of the top twenty tornado-prone states for the month of May. The rankings, based on National Weather Service data from 1950 through 2007, are as follows:
|
Rank |
State |
ACF (%) |
Disturbed Land Area (Acres) |
|
1 |
Oklahoma |
0.01722 |
7571 |
|
2 |
Kansas |
0.01639 |
8581 |
|
3 |
Nebraska |
0.01563 |
7661 |
|
4 |
Pennsylvania |
0.01041 |
2999 |
|
5 |
Iowa |
0.00922 |
3304 |
|
6 |
Arkansas |
0.00594 |
1982 |
|
7 |
Illinois |
0.00581 |
2069 |
|
8 |
Alabama |
0.00580 |
1886 |
|
9 |
South Dakota |
0.00452 |
2200 |
|
10 |
Missouri |
0.00391 |
1723 |
|
11 |
Ohio |
0.00361 |
946 |
|
12 |
Kentucky |
0.00358 |
909 |
|
13 |
Texas |
0.00335 |
5621 |
|
14 |
Wisconsin |
0.00325 |
1132 |
|
15 |
Indiana |
0.00300 |
689 |
|
16 |
Mississippi |
0.00272 |
821 |
|
17 |
Tennessee |
0.00257 |
678 |
|
18 |
South Carolina |
0.00230 |
445 |
|
19 |
North Carolina |
0.00230 |
718 |
|
20 |
Louisiana |
0.00213 |
608 |
The ACF "Annual Coverage Fraction" represents the average fraction of land area within the boundaries of the state disturbed by tornadoes during May for the 58-year period from 1950 through 2007. The "disturbed land area" represents the average number of acres of land within the boundaries of the state disturbed by tornadoes during May for the same 58-year period.