Specific Differential Phase Signatures Associated With Quasi-Linear Convective System Mesovortices

Issuing convective warnings on mesovortices within quasi-linear convective systems (QLCSs) is a challenge for National Weather Service operations, as these rotation signatures develop quickly and are small-scale phenomena. To guide forecasters, the three ingredients method and QLCS mesovortex warning system were developed. However, this system doesn’t yet incorporate dual-polarization radar data other than tornadic debris signatures. Therefore, this study compares mesovortex evolution and strength to the evolution of specific differential phase (KDP) to determine if KDP offers any predictive ability (lead time) to mesovortex development and damage potential. To accomplish this study, we compared low-level KDP core, midlevel KDP core, and KDP drop evolution relative to mesovortex formation. We chose three QLCS events, 19 May 2022 in the Saint Louis county warning area (CWA), 20 February 2017 in the San Antonio CWA, and 10 January 2020 in the Memphis CWA, and examined the KDP signatures mentioned above for damaging vs non-damaging mesovortices and tornadic vs non-tornadic mesovortices. In general, KDP drops frequently precede mesovortex development and are slightly more frequent for mesovortices that produce damage. Furthermore, 65% of all KDP drops led to either a mesovortex or damage. Midlevel KDP cores have a higher magnitude for tornadic and damaging mesovortices prior to mesovortex genesis, therefore potentially offering prognostic ability. Furthermore, low-level KDP cores have a higher magnitude for tornadic and damaging mesovortices during mesovortex life, therefore potentially offering diagnostic ability. These findings support the idea that KDP can be used by forecasters to build confidence in whether a given mesovortex might produce damage or not.