WSR-88D radar characteristics of quasi-linear convective system tornadoes using the NSSL Severe Storm Analysis Program

An estimated 18% of all tornadoes in the continental United States are spawned by Quasi-Linear Convective Systems (QLCSs). Although QLCS tornadoes are a non-trivial proportion of the total yearly number of tornado occurrences, their characteristics, as well as those of their parent storms, are just now being studied in depth.

The authors have complied a set of QLCS tornadoes that spans 1998 and 1999. From the events in the set, radar data of 80 tornado events from 18 different locations were examined using the National Severe Storms Laboratory's (NSSL) Severe Storm Analysis Program (SSAP). The SSAP is a set of WSR-88D based algorithms that include the Mesocyclone Detection Algorithm (MDA) and the TVS Detection Algorithm (TDA). Diagnostic parameters from the MDA and TDA include "maximum gate-to-gate velocity difference", "mesocyclone base", and "TVS depth", to name a few. A statistical analysis of the MDA and TDA parameters for the 80 tornadoes will hopefully provide some coherent characteristics specific to QLCS tornadoes.

This study follows up on work presented in the 31st Conference on Radar Meteorology.