| |
|
|
T A S
C
Tornado Alley Sailing
Club does not advise sailing during
thunderstorms, but TASC is located in what is known
in the United States as "Tornado Alley".
TASC attracts dinghy sailors from the states of Tennessee, Arkansas and
Mississippi.
Since 1950, there have been more than 2,395 tornadic
events in these three states, 91 of those reported to have touched down
in the five counties where we race. Since 1950, at least
846 people have been killed in these states by the detritus thrown around violently by
tornadoes; these same tornadoes injured at
least 11,633 people.
Below is a small chart showing the frequency of tornadoes each month
in the states of Tennessee, Arkansas and Mississippi. As you can see, most
tornadoes occur in late spring.
| Month |
JAN |
FEB |
MAR |
APR |
MAY |
JUN |
JUL |
AUG |
SEP |
OCT |
NOV |
DEC |
| Average # of Tornados |
2 |
6 |
9 |
25 |
12 |
6 |
1 |
3 |
1 |
2 |
4 |
2 |
Tornadoes were first scientifically categorized by Dr. Theodore
Fujita. He collaborated with Dr. Pearson to create the Fujita-Pearson Scale,
which compares the wind speed, destructive intensity and catastrophic effects of
various tornadoes.
Fujita-Pearson Scale
| F0 very weak |
40-72 mph |
removes roof shingles |
| F1 weak |
73-112 mph |
overturns small cars |
| F2 strong |
113-157 mph |
destroys mobile homes |
| F3 severe |
158-206 mph |
flattens entire forests |
| F4 devastating |
207-260 mph |
can throw large steel objects great distances |
| F5 incredible |
261-318 mph |
levels buildings and then removes the debris |
| F6 inconceivable |
318 mph to Mach 1 |
vast devastation |
 Advancing walls of thunderstorms sometimes spawn more than one vortex
at the same time. These situations are naturally very dangerous, yet this jumble
of vortices can then combine into what are called super-cells. These are
storms of tremendous intensity and dynamism. Thunderstorms that transform into
complex super-cells are almost always very destructive and dangerous.
These charts show every tornado recorded as having occurred1985-95 in the five counties of the Memphis area: Crittenden and
St.Francis Counties in Arkansas, Desoto and Tunica Counties in Mississippi,
and Shelby County, Tennessee.
Crittenden County, Arkansas
| Date |
Time of Day |
Dead |
Injured |
Fujita Scale |
| 5/1/85 |
17:45 |
0 |
0 |
F1 |
| 12/14/87 |
21:40 |
6 |
100 |
F3 |
| 6/4/89 |
17:45 |
0 |
0 |
F0 |
| 6/2/90 |
21:05 |
0 |
0 |
F0 |
| 11/27/94 |
14:25 |
0 |
0 |
F1 |
| 11/27/94 |
14:30 |
0 |
2 |
F1 |
St. Francis County, Arkansas
| Date |
Time of Day |
Dead |
Injured |
Fujita Scale |
| 7/29/92 |
13:30 |
0 |
0 |
F1 |
Desoto County, Mississippi
| Date |
Time of Day |
Dead |
Injured |
Fujita Scale |
| 3/12/86 |
01:30 |
0 |
0 |
F1 |
| 1/19/88 |
10:12 |
0 |
1 |
F2 |
| 8/5/93 |
16:30 |
0 |
0 |
F0 |
| 4/26/94 |
17:03 |
0 |
0 |
F0 |
| 4/26/94 |
18:05 |
0 |
0 |
F0 |
| 6/9/94 |
11:02 |
0 |
0 |
F0 |
Tunica County, Mississippi
| Date |
Time of Day |
Dead |
Injured |
Fujita Scale |
| 2/23/85 |
16:05 |
0 |
0 |
F1 |
| 2/23/85 |
16:15 |
0 |
0 |
F0 |
| 2/17/86 |
16:20 |
0 |
0 |
F1 |
| 2/17/86 |
16:25 |
0 |
0 |
F1 |
| 6/9/94 |
11:00 |
0 |
0 |
F0 |
Shelby County, Tennessee
| Date |
Time of Day |
Dead |
Injured |
Fujita Scale |
| 12/14/87 |
21:52 |
0 |
21 |
F3 |
| 5/22/88 |
16:30 |
0 |
0 |
F0 |
| 6/4/89 |
18:30 |
0 |
0 |
F2 |
| 6/4/89 |
19:00 |
0 |
0 |
F1 |
| 11/7/89 |
20:00 |
0 |
0 |
F0 |
| 3/27/91 |
13:20 |
0 |
0 |
F1 |
| 11/19/91 |
17:05 |
0 |
0 |
F1 |
| 3/18/92 |
08:20 |
0 |
0 |
F0 |
| 6/9/94 |
11:58 |
0 |
0 |
F0 |
| 6/9/94 |
12:10 |
0 |
0 |
F1 |
| 11/27/94 |
15:15 |
3 |
25 |
F3 |
| 5/15/95 |
09:45 |
0 |
0 |
F0 |
More Information: www.spc.noaa.gov/faq/tornado/
|
|
|
|
| |
|
