Comparative Analyses of Nontornadic versus Tornadic Quasi-Linear Convective Systems in Central Oklahoma 24–25 May 2019

Two quasi-linear convective systems (QLCSs) impacted the Oklahoma City metro area on consecutive evenings of 24-25 May 2019. Mesovorticies along the gust front of the 24 May 2019 QLCS were shallow and slightly cold pool dominant, while those associated with the subsequent 25 May 2019 QLCS were deep and more balanced along the updraft-downdraft convergence zone. The former was non-tornadic, while the latter produced a rare, EF-3 tornado in El Reno, Oklahoma, resulting in two fatalities. Both of these QLCS mesovortex events were well-sampled by the Twin Lakes (KTLX) WSR-88D and Oklahoma City terminal (TOKC) Doppler radars with high-resolution environmental data captured by the Oklahoma Mesonet and other observation sources. This study includes detailed analyses of both the mesoscale environment and radar of the non-tornadic and tornadic QLCSs. Particular emphasis will be placed upon the application of mesoanalysis and the QLCS three-ingredients method, both of which supported messaging to core partners and warning decisions limiting false alarms for the first event while providing adequate warning for the El Reno tornado. Best practices and challenges associated with the current QLCS tornado forecast and warning paradigm are discussed as well as operational needs for additional research-to-operations (R2O) necessary to improve lead time and limit false alarms.