High-resolution polarimetric radar observations by OU-PRIME during the 10 May 2010 tornado outbreak in central Oklahoma

During the 10 May 2010 tornado outbreak, OU-PRIME (Polarimetric Radar for Innovations in Meteorology and Engineering) obtained a remarkable dataset including numerous supercells and several tornadoes, including five strong or violent tornadoes. In fact, one of these tornadoes developed just 200 yards from the radar site, very near the National Weather Center on the University of Oklahoma campus. Owing to its 0.45º beamwidth, OU-PRIME is one of the highest resolution polarimetric radars in the world. OU-PRIME transmits a peak power of 1 MW and possesses a high-gain antenna, giving OU-PRIME extremely high sensitivity. An overview of the OU-PRIME data collected during the 10 May 2010 outbreak will be presented, emphasizing the capabilities of this high-resolution, high-sensitivity polarimetric radar. One supercell produced an EF4 tornado in Moore, Oklahoma and southern Oklahoma City, and the full period of tornadogenesis was captured by OU-PRIME. The reflectivity appendage exhibited a distorted structure, and numerous regions of cyclonic and anticyclonic rotation along the reflectivity appendage. Several well-documented polarimetric signatures of supercells and tornadoes were observed in this dataset. The ZDR arc is prominently seen at low-levels with ZDR values as high as 8 dB. Other polarimetric features include signatures of large hail, and midlevel ρhv and ZDR rings. In addition to these supercell signatures, the tornadoes produced clear tornadic debris signatures (TDSs), and differences in the horizontal and vertical extent of the TDS were observed. The evolution of these polarimetric signatures during and after tornadogenesis will be discussed.