During the VORTEX-SE field campaign, 16 Texas Tech University “StickNet” probes observed the equivalent potential temperature and virtual potential temperature deficits within the cold pools of supercell thunderstorms and QLCSs. These measurements were motivated by previous observational studies which showed tornadic storms tend to have weaker temperature deficits and higher buoyancy in their flanking downdraft regions than nontornadic supercells. However, there are no studies that consider the cold pool deficits between tornadic and non-tornadic segments of QLCS events.
This study will compare the potential temperature deficits and cold pool evolution of tornadic and nontornadic supercells and QLCS circulations sampled during VORTEX-SE. We will also show that the cohesiveness of a cold pool edge and the rate of buoyancy decrease may also be important for tornadogenesis by virtue of the implied baroclinic vorticity generation. A QLCS on 30 April 2017 showed relatively smaller equivalent potential temperature deficits associated with two mesovortices, one of which was weakly tornadic and another which was tornado-warned but nontornadic. The tornadic mesovortex was also associated with one of the largest virtual potential temperature gradients within that QLCS, thereby differentiating the tornadic and nontornadic mesovortices. This feature has been identified in at least one other VORTEX-SE QLCS event. These results will help establish a climatology of southeastern supercell and QLCS cold pool deficits and characteristics, components of which may shed light on mechanisms for tornadogenesis.