A Synoptic, Mesoscale and Radar Review for the Southeast Tennessee Tornado Outbreak of 30 November 2016

During the early morning hours of 30 November 2016, a significant tornado outbreak occurred across the southern Tennessee Valley, which included southeast Tennessee and northern Alabama. Three strong tornadoes occurred in the National Weather Service Morristown, Tennessee County Warning Area (CWA). The strongest tornado, an EF3, occurred near Ocoee, TN where there were 2 fatalities. For the entire event, there were 2 fatalities and 22 injuries. In addition to tornadoes, there were numerous reports of damaging winds.

This was an unseasonable tornado outbreak for southeast Tennessee. A strong upper-level jet moved across the western Tennessee and Ohio Valleys and provided a spring-like kinematic and thermodynamic profile across the southern Tennessee Valley. The potential for significant severe weather was well understood by forecasters across the northern Gulf Coast states, but was not expected to reach northward into southeast Tennessee. The strength of the upper-level jet and the enhanced low-level boundary jet allowed a warm front to move north, bringing unseasonably warm and unstable air to the CWA, and provided a mesoscale focus for enhanced tornadogenesis.

This presentation will focus on the overall synoptic, mesoscale, and environmental evolution of this significant tornado outbreak and provide a radar review of the three strong supercells. Since the tornado outbreak was not well forecast, a thorough understanding of the evolution of this event will aid forecasters for similar systems.