Comparing snowstorms with and without lightning via the growth rate parameter

The seldom utilized growth rate parameter (σ²) is applied to study the stability characteristics of thundersnow events across the central United States during the winter seasons of 2003-04 and 2004-05. The goal is to provide more insight into how the environment becomes destabilized over a relatively short period of time, as well as determine approximately where and when elevated thunderstorms develop. Results show that the development of cold season precipitation with lightning (e.g., thundersnow), and any associated banding, is correctly and most accurately predicted from trends in plots of σ². To emphasize the significance of the diagnostic results, comparisons are made against a set of non-thundering snowstorms. Work with σ² has been infrequent since its introduction, with little of that occurring in reference to North American precipitation systems. With the advent of moist potential vorticity, the meteorological community would seem to have paused in this line of inquiry. When complete, we hope that this work will provide additional information into how likely and quickly wintertime convection is expected to develop. Examinations of traditional sounding parameters, radar reflectivity patterns, and cloud-to-ground (CG) lightning data from the National Lightning Data Network (NLDN) will aid in verification efforts.