Examining the Relative Motion of Derecho- and Non-Derecho-Producing QLCSs with Respect to the Mean Wind

Since the term “derecho” was defined, vast technological and societal changes have taken place. Impactful developments include (1) the implementation of the WSR-88D radar network nationwide, which helps provide a view of the structure and evolution of mesoscale convective systems (MCSs), and (2) modern reporting practices which now provide substantially more severe-wind reports than in the past. These changes have caused the term “derecho” to become misapplied over the years, which has led to recent endeavors to refine the definition. This study aims to help clarify the term “derecho” by investigating relationships between radar-implied structural features of MCSs and the mean wind and propagation components of MCS motion. Results show that there is a correlation; specifically, well-organized MCSs move faster and have more propagation in the direction of mean wind than less organized systems. By understanding the relationship between MCS structure and motion, the process of MCS and derecho classification can incorporate physical features and motion of MCSs, in addition to wind-damage swaths, into the classification process.