Integrated Polarimetric Radar and Kinematic Analyses of the 19 May 2013 Norman-Shawnee, Oklahoma Tornadic Supercell

High-resolution supercell intercomparisons between polarimetric radar observations and the 3D wind field via dual-Doppler analysis retrievals are generally difficult to construct and rarely performed. To synthesize dual-Doppler analyses using a grid spacing that allows for storm-scale features to be resolved typically requires at least one system to be a mobile radar because of the relatively large distances between fixed site radars. However, polarimetric radar data from mobile radars are often inferior to that from the WSR-88D network owing to data quality problems such as attenuation and the lack of volumetric data from storm mid and upper levels. Therefore, polarimetric radar data comparisons with kinematic fields in supercells optimally use data from both fixed site and mobile radar systems utilizing different center frequencies.

On 19 May 2013, a supercell that produced a violent (EF4) tornado near Shawnee, Oklahoma was observed, including during tornadogenesis, by five different Doppler radars: three dual-polarization, S-band, fixed site radars (KTLX, KOUN, and KCRI), one S-band, fixed site, phased array radar (MPAR), and one dual-polarization, X-band, mobile radar (NOXP). Data from the array of radar systems are used to compare polarimetric data at two different radar frequencies (X and S band) with kinematic analyses synthesized using data from at least two of these radars. Direct comparisons between several observed polarimetric radar signatures and the 3D wind field will be presented, likely including the tornadic debris signature, Z_DR arc, and Z_DR column. The focus of the comparisons are on (i) the cause of the polarimetric signatures and (ii) the relationship between the kinematic field and the evolution of the polarimetric variables during important storm processes.