Dynamical Processes Perturbing Right-Moving Supercell Storm Motions

Right-moving supercell thunderstorms often display the following behavior prior to tornadogenesis: 1) a slowing in storm motion, and 2) increased rightward movement from the hodograph’s mean 0-6 km wind vector. This behavior has been noted in both observations and numerical simulations. While the Bunkers right-moving storm motion estimate (BRME) accounts for the supercell’s rightward propagation and tropospheric wind, there are intra- and extra-storm characteristics that cause deviations from the BRME. These deviations are theorized to alter streamwise vorticity into the updraft, low-level updraft dynamics, and thus the potential for tornadogenesis. We performed 27 simulations of supercells in a range of environments within an idealized cloud model (the Bryan Cloud Model 1, “CM1”). Of these 27 simulated supercells, 14 exhibit substantial storm motion changes relative to the BRME. We will evaluate the cold pool dynamics, updraft rotation, hydrometeor fields, and inflow characteristics of these 14 storms and how these properties relate back to the low-level wind profile. The overarching research goal is to identify which storm characteristics and processes are responsible for creating substantial perturbations from BRME. Our long-range goal is to relate these changes in storm motion to shifts in the probability of tornadogenesis by supercells.