The Impact of Terrain on Supercells Using Idealized Numerical Simulations

Terrain heterogeneity and land surface characteristics over the southeastern United States play a role in the development and evolution of severe convection. These surface features including steep ridges, valleys, and plateaus allow for thermodynamic and kinematic heterogeneities to develop that enhance the mesoscale environment and tornado potential over a regional area. The impact of these terrain-induced environmental changes on the supercell have not been examined in depth.

This ongoing study investigates the impact of realistic terrain features on supercells using high-resolution Cloud Model 1 (CM1) simulations. Several terrain features of various slopes are taken from the southeastern United States are implemented into CM1. Past events from the southeastern United States are simulated to investigate the terrain features affect on the mesoscale environment. Supercell evolution will be diagnosed to show how these various terrain features and their effect on the environment enhance or diminish storm characteristics (e.g., updraft tilt, mesocyclone strength, and propagation speed). The dependency of terrain slope and orientation on the mesoscale environment and on the supercell thunderstorm will also be assessed.