Surface Layer Influences on Supercell Thunderstorms

While low-level (nominally 0-1 km) environmental kinematic and thermodynamic properties have been shown to have some skill in discriminating between tornadic and nontornadic supercells,  a growing body of work suggests that aspects of the near-storm environment (e.g., the wind profile, temperature lapse rate, surface roughness, soil moisture, and low-level relative humidity) in even shallower layers (<500 m) may be important in supercell tornadogenesis.  Supercell thunderstorms are simulated with and without full surface physics in idealized environments varying surface and near-surface  (i.e.,  surface layer) characteristics that may affect both the ambient and internal flow within the storms.   The effects of horizontal variations in surface-layer characteristics on supercell dynamics will also be explored.  Results from this and previous studies examining the effects of shallow changes in the near-storm environment on both observed and simulated storms will be presented.