The Sensitivity of Supercell Thunderstorm Behavior Near Complex Terrain in the Central and Southern Appalachians

Complex terrain has a significant impact on weather systems, including supercell thunderstorms. However, the extent to which these impacts are sensitive to the maturity of the supercell or its angle of approach to the terrain is not well understood. Our hypothesis is that supercells are more likely to be enhanced when they are in their most intense, mature stage and directly approach topographical features. This hypothesis is systematically tested with idealized CM1 simulations of supercell thunderstorms interacting with the complex terrain of the central and southern Appalachian Mountains. Differing maturity levels are imposed by varying the initiation location of the supercell, while the approach angle is tested by rotating the hodograph of the background environment. Comparisons of behavior will also be made relative to simulations with flat terrain. The results will show how the supercell and its mesocyclone evolve as it encounters the terrain, quantifying the impact that complex terrain has on supercell thunderstorms and the dependence on maturity and approach angle.