A multiple-wavelength polarimetric analysis of the 16 May 2010 Oklahoma City hailstorm

During the afternoon of 16 May 2010, a supercell thunderstorm produced a swath of extremely damaging hail across a large portion of the Oklahoma City metro area. Hail sizes over 10 cm in diameter and hail drifts upwards of 1.5 m in height were reported. Total damage costs from the storm are estimated to be over $500 million, which is approximately half of the average annual losses from hail in the entire United States. However, due to the track and intensity (both size and amount of hail produced) of the storm, it presents an extremely unique case to analyze. Both S-band (KOUN) and C-band (OU-PRIME) polarimetric radars in Norman, Oklahoma sampled the storm at ranges less than 60 km, yet still separated from ground clutter, allowing for a high quality, multiple-wavelength polarimetric analysis. Additionally, the lack of other storm cells between the two radars and this hailstorm ensures that attenuation issues when comparing the radar data are minimized. Therefore, observed differences in the polarimetric variables, such as differential reflectivity Z_DR and cross-correlation coefficient ρ_hv, between the two wavelengths reveal particularly useful information regarding the bulk microphysical properties of the hydrometeors within a resolution volume. Differential attenuation and resonant scattering effects, enhanced at the 5-cm wavelength of C band, are utilized to differentiate regions of smaller melting hailstones from regions of more significant hailstones over 4-5 cm in diameter. Furthermore, due to a storm track within such a highly populated area, this study takes advantage of an increased number of ground-truth hail reports than are typically available with any one hailstorm.