RUC-2 Supercell Proximity Soundings, Part I: An Examination of Storm-Relative Winds Normalized to Supercell Depth

Rapid Update Cycle 2 (RUC-2) model soundings were collected for a large, nationwide sample of tornadic and nontornadic supercells during 1999 and 2000. One sounding was obtained for each of >250 radar identified supercells, with the nearest available RUC grid point data in the inflow sector of the supercell serving as an effective proximity sounding. In the first part of our examination, we will analyze the model soundings for various storm-relative (SR) winds, using layers whose depth and height are scaled to the height of the equilibrium level. Our primary intent is to improve upon published storm-relative wind parameters tied to fixed mandatory levels by incorporating an indicator of variable storm depth, and also, to allow more reliable discrimination between tornadic and nontornadic supercell environments.