Wednesday, April 15, 2009

Mid-South at greatest risk for tornado deaths

Relative Frequency of Killer Tornadoes, 1950-2004

While Tornado Alley has always been the hot spot for tornado occurrence in the United States, a lesser-known alley - "Dixie Alley" - produces the most killer tornadoes. As reported last month by the State Gazette out of Dyersburg, TN, Dixie Alley has about the same number of strong and violent tornadoes, but more killer tornadoes than it's more more widely-known cousin. The graphic above highlights the frequency of killer tornadoes that occur in the Mid-South.

Dixie Alley encompasses the Mid-South and includes AR, west and middle TN, LA, MS, AL, and most of GA. The reason for the higher propensity of deadly tornadoes can likely be attributed to several factors. These include the frequency of nighttime events, a higher percentage of mobile homes, hilly and forested terrain that makes it harder to visually spot tornadoes, and a longer severe weather season that may lower residents guard. Tornado Alley tends to have a shorter severe weather season, flat terrain that allows storms to be seen miles away, and lower population density. An excellent presentation comparing the two regions was made by NWS forecasters, led by Alan Gerard.

All of this points to the need for Mid-Southerners to be keenly aware of impending severe weather threats and be familiar with what they would do if severe weather, particuarly tornadoes, occur. They can occur at any time, in any month (with a pronounced "season" from November through May). The National Weather Service has done a phenomenal job of improving warning lead times and accuracy in their warning process. It's now up to you to heed the warnings and always know the plan of action, wherever you may be. Last year's Super Tuesday tornadoes and the Good Friday tornadoes in middle TN last week are proof that "it doesn't happen here" is simply false. For more information on tornado preparedness, check out this NWS Tornado Publication (PDF) and website or download and print the MWN Severe Weather Safety Tips (PDF). Also, every family should own, maintain, and keep turned on, a NOAA Weather Radio - it could be what saves your life in the middle of the night!

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