Dual-Polarization Radar-based Analysis of Supercell Evolution: Comparing Phased Array and WSR-88D Observations

As the National Weather Service considers the options for replacing current Weather Surveillance Radars-1988 Doppler (WSR-88Ds), phased array radar (PAR) is one replacement option under consideration. Thus, identifying use cases to examine how PAR data may offer improvements over WSR-88D observations becomes crucial. One potential target use case type involves the identification of dual-polarization features in severe convection, which provide insights into various storm-scale processes and structures relevant to operations. With significantly faster full volume scans than existing WSR-88Ds, PARs can resolve the evolution of dual-polarization signatures more clearly and at a higher temporal frequency. This project investigates potential benefits of PAR via comparison of dual-polarization radar signatures – as well as output from a dual-polarization signature identification algorithm – across PAR and WSR-88D radar data. PAR data was collected by the Advanced Technology Demonstrator (ATD) PAR at NOAA’s National Severe Storms Laboratory in Norman, OK, and WSR-88D observations were collected from the co-located KOUN and nearby KTLX WSR-88D radars. Depictions of multiple supercell dual-polarization signatures, including ZDR arcs, ZDR - KDP separation vectors, and ZDR columns, are qualitatively analyzed for a selection of central Oklahoma supercell events, including the 27 April 2024 and 06 May 2024 cases. Further, quantitative output from a modified version of the Supercell Polarimetric Observation Research Kit (SPORK), an algorithm designed to identify and quantify features of dual-polarization signatures, is collected for each case. Meteorological implications of differences between WSR-88D and ATD returns are explored, with a particular focus on both the operational utility and limitations of SPORK output applied to rapid-update ATD data.