Tennessee Tornado Climate A Comparison of Three Cities

Tornado frequency characteristics and human vulnerability are assessed within 100 km of three major Tennessee cities (Nashville, Memphis, and Knoxville) between 1950 and 2013. Focusing on cities and their surrounding areas provides insight on tornado characteristics across different longitudinal portions of the state while also diminishing bias due to underreported tornadoes in rural areas. Nashville reported the most tornadoes between 1950 and 2013 (426), followed by Memphis (390), and Knoxville (176). Knoxville and Nashville tornadoes occurred on fewer days, while Memphis's tornadoes were spread across more tornado days. Spring was the most active season for tornadoes, but Memphis still experienced approximately 25 percent of tornadoes in the winter, a season prone to nocturnal tornadoes. Memphis also averages the most tornado-related fatalities (four per year). Future work should investigate if social factors are the primary cause of increased vulnerability in Memphis, or if the higher number of tornado days, especially during the winter, plays a role in the increased fatalities seen there. The occurrence of more tornadoes across fewer days and increased winter activity may impact human preparedness and response.