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

Authors

Caitlyn Scott, University of Nebraska-LincolnFollow

First Advisor

Matthew Van Den Broeke

Second Advisor

Adam Houston

Date of this Version

3-27-2025

Document Type

Thesis

Citation

Scott, Caitlyn, Matthew Van Den Broeke, and Adam Houston. Specific Differential Phase Signatures Associated With Quasi-Linear Convective System Mesovortices. Undergraduate Honors Thesis. University of Nebraska - Lincoln. 2025

Comments

Copyright Caitlyn Scott, Matthew Van Den Broeke, and Adam Houston 2025

Abstract

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 (K_DP) to determine if K_DP offers any predictive ability (lead time) to mesovortex development and damage potential. To accomplish this study, we compared low-level K_DP core, midlevel K_DP core, and K_DP 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 K_DP signatures mentioned above for damaging vs non-damaging mesovortices and tornadic vs non-tornadic mesovortices. In general, K_DP drops frequently precede mesovortex development and are slightly more frequent for mesovortices that produce damage. Furthermore, 65% of all K_DP drops led to either a mesovortex or damage. Midlevel K_DP cores have a higher magnitude for tornadic and damaging mesovortices prior to mesovortex genesis, therefore potentially offering prognostic ability. Furthermore, low-level K_DP cores have a higher magnitude for tornadic and damaging mesovortices during mesovortex life, therefore potentially offering diagnostic ability. These findings support the idea that K_DP can be used by forecasters to build confidence in whether a given mesovortex might produce damage or not.