Association between Rear Flank Gust Front Mesocyclone-relative Position and Supercell Microphysical Variability

Thermodynamic properties of rear-flank downdrafts (RFDs) are believed to have significant effects on near-surface vertical vorticity stretching, mesocyclone enhancement, and tornado genesis/maintenance/dissipation. WSR-88D data allow for the detection of RFDs, and the associated rear flank gust front (RFGF), in many supercells. We analyze radar-derived properties of supercell RFDs and their variability by environment, using several cases collected by the WSR-88D network. Cases optimal for examining properties of the RFD should lie near (within 75 km of) the radar location. Focus will be placed on storm-relative velocity and mesocyclone-relative position of the RFGF. These characteristics will be related to drop size distributions and spatial extent of hail in the RFD region, inferred using polarimetric variables. RFGF properties will be compared with low-level moisture in the supercell environment, and with the ambient low-level vertical wind profile.