Potential Vorticity Upscale Feedbacks Observed During the Mesoscale Predictability Experiment (MPEX)

Radiosonde data were collected by the ground-based teams (Purdue, NSSL, Colorado State, and Texas A&M) involved in the Mesoscale Predictability Experiment (MPEX) during the spring of 2013. Potential vorticity calculations and interpolations based on these soundings may help to quantify changes in the atmosphere in the "wake" of a supercell thunderstorm. We have previously found (in the studies of the Tuscaloosa and Joplin tornadic supercells) that these smaller storms (in terms of time and space compared to mesoscale convective vortices) generate mid-tropospheric vertical vorticity on the meso-alpha scale. These "upscale feedbacks" persist much longer and are on a larger spatial scale than the parent storm itself. Case studies include both the May 20, 2013 and May 31, 2013 tornado outbreaks in central Oklahoma.