A Comparison of Warm and Cool Season Tornadic Quasi-Linear Convective Systems in North Alabama

Tornadoes that accompany quasi-linear convective systems are often difficult to detect. Previous work has indicated approximately 90% of tornadic storms in northern Alabama are associated with convective lines.

In an effort to better understand and recognize these phenomena we will present two cases of quasi-linear convective system tornados that produced EF-2 damage. On 8 May 2008, seven tornadoes were reported in the WFO Huntsville county warning area, including one EF-2 which began near Leighton, Alabama and tracked 9.6 miles across three counties. The storm that spawned the tornado took on super-cellular traits which may have lengthened the life of the tornado. On 10 December 2008, an EF-2 tornado of much shorter duration and track was associated with a bow echo exhibiting a more classic quasi-linear system tornadic evolution.

The presentation will focus on analyses of the near storm environments and the new super resolution radar data from the North Alabama WSR-88D, supplemented with radar data from the University of Alabama at Huntsville. Video taken of the Leighton, Alabama tornado will be shown and storm survey results will be discussed.