The Role of Hook Echo Microbursts in Simulated Tornadic Supercells. Part I Association with counter-rotating vortices and tornadogenesis

The apparent relationship observed between microbursts (a.k.a., descending reflectivity cores; DRCs) within the supercell hook echo and impending tornado formation has been documented for a handful of supercells by Rasmussen et al. (2006). Several of these occurred on 2 June 1995 (VORTEX-1) in close proximity to a sounding launch site. Using that sounding, we simulate a tornadic supercell and study the relationship between the simulated DRC and tornadogenesis. We use two versions of a new sophisticated microphysics scheme by Straka and Gilmore (2007) that is capable of better representing the precipitation properties of the supercell and associated microburst.

In part I, we present our preliminary findings of the dynamic role of the DRC in tornadogenesis and its association with the counter-rotating vortices.