Thermodynamic and Kinematic Analysis of Supercells using High Resolution In Situ Data from Texas Tech StickNet Instrument Systems

In May and June of 2009 and 2010, over 100 scientists, students and volunteers embarked on the largest tornado research project in history: The Verification of the Origins of Rotation in Tornadoes EXperiment II (VORTEX II). This scientific armada was equipped with the latest technologies in the field - including several mobile Doppler radars, surface observation platforms, radiosondes, and disdrometers - and aimed to quantify the environment within and surrounding tornadic supercells to an unprecedented degree. Texas Tech played an integral role in this project by deploying a total of 650 StickNet platforms, designed specifically for safely measuring crucial thermodynamic and kinematic variables within hostile regions of storms.

Of critical importance to the numerous scientific objectives sought out in VORTEX II is the observation and analysis of baroclinity within tornadic and non-tornadic supercells. In recent decades, numerous observational and modeling studies have revealed that streamwise vorticity generation due to baroclinity is critical to low-level mesocyclogenesis and tornadogenesis. Although much has been learned from these studies, scientists' understanding of baroclinity within supercells remains largely incomplete, and thus a clear relationship to tornadogenesis remains elusive. Furthermore, recent dual-Doppler and in situ studies have shown significant kinematic variability within the rear flank downdraft of supercell thunderstorms, particularly the presence of secondary downdraft surges which may have an effect on the vorticity budget within tornadic or potentially tornadic supercells (Wurman et al. 2007; Hirth et al. 2008). In this presentation, StickNet data from select VORTEX II cases will be used to analyze the thermodynamic and kinematic properties of the left and right flank regions of supercells, with a specific emphasis on persistent small scale perturbations within the RFD region of pre-tornadic and tornadic storms.