Observations of the 10 may 2010 tornado outbreak using OU-PRIME: Potential for new science with high-resolution polarimetric radar

The 10 May 2010 tornado outbreak devastated parts of Oklahoma with 55 tornadoes, including several strong and violent tornadoes. Researchers in the ARRC operated OU-PRIME on 10 May 2010, capturing a rare dataset of two cyclic supercells producing four tornadoes of EF-2 to EF-4 intensity near the radar (less than 5 km in one case). The 0.45° intrinsic beamwidth of OU-PRIME, high sensitivity, and the application of the multilag estimation resulted in very high-resolution and high-quality polarimetric data of these supercells and tornadoes. The 10 May 2010 OU-PRIME dataset has tremendous potential for polarimetric studies of supercells and tornadoes. OU-PRIME collected data at numerous lowlevel elevation angles during the tornadogenesis of the Moore EF-4 tornado, revealing a contorted reflectivity appendage and relatively small-scale vortices along the RFD gust front prior to tornadogenesis. During tornadogenesis of tornadoes A1 and A2, rain curtains are drawn in from the forward-flank precipitation of storm B, providing an opportunity to investigate the interactions of the two storms. Many supercell polarimetric signatures were also observed in this dataset. The evolution of the Z_DR arc was consistent with previous polarimetric observations of cyclic supercells and exhibited a classic shape just prior to tornadogenesis of an EF-3 tornado that struck Tecumseh and Seminole, Oklahoma (Fig. 1). The tornadoes exhibited obvious TDSs (low ρ_hv and low Z_DR), and the TDSs varied in horizontal and vertical extent. The NFTDA tornado detections agreed well with the National Weather Service (NWS) damage paths for most of the tornadoes with EF-2 intensity or greater. Researchers at the ARRC, OU, and collaborating institutions have started analyzing this unique dataset. Future efforts with this dataset include investigating the evolution of substorm-scale vortices, low-level winds during tornadogenesis, and polarimetric signatures associated with the supercells and tornadoes. New schemes may be developed for detecting hail, determining hail size, and correcting attenuation at C band. Furthermore, efforts to assimilate the polarimetric radar measurements are underway to assess the possible benefits of polarimetric data in numerical models (Jung et al. 2008a,b). These studies have the potential to advance our understanding of tornadogenesis, storm structure, and interactions and to discover new applications of polarimetric radar in meteorology and engineering.