Discriminating Among Non Severe, Severe, and Derecho-Producing Mesoscale Convective System Environments

Previous studies have identified meteorological variables linked with intense mesoscale convective systems (MCSs) known as derecho-producing MCSs (DCSs). The prediction of MCS intensity is of concern to operational meteorologists, and this study provides discussion on meteorological variables derived from proximity soundings that can be used to discriminate among DCSs, severe but non derecho-producing MCSs (SCSs), and non severe MCSs (NCSs). These variables have been grouped into three categories: kinematics, instability, and moisture. Two-hundred sixty-nine warm season MCSs were rated based on intensity, and the stage of each system within the typical MCS lifecycle was assessed. Decaying and dissipating MCSs were removed from the data set to focus on the most intense stages of the MCS lifecycle. Variables were calculated from proximity soundings associated with each MCS, and statistical analyses were performed on these calculations. System-relative inflow and mid-level environmental lapse rates were found to be variables that discriminate among all three MCS environments. Knowledge of the variables affecting MCS intensity can allow for improved forecasts and warnings of convective wind events.