Observations of the 10 May 2010 Tornado Outbreak Using OU-PRIME: Potential for New Science with High-Resolution Polarimetric Radar

Abstract

A tornado outbreak occurred in central Oklahoma on 10 May 2010, including two tornadoes with enhanced Fujita scale ratings of 4 (EF-4). Tragically, three deaths were reported along with significant property damage. Several strong and violent tornadoes occurred near Norman, Oklahoma, which is a major hub for severe storms research and is arguably one of the best observed regions of the country with multiple Doppler radars operated by both the federal government and the University of Oklahoma (OU). One of the most recent additions to the radars in Norman is the high-resolution OU Polarimetric Radar for Innovations in Meteorology and Engineering (OU-PRIME). As the name implies, the radar is used as a platform for research and education in both science and engineering studies using polarimetric radar. To facilitate usage of the system by students and faculty, OU-PRIME was constructed adjacent to the National Weather Center building on the OU research campus. On 10 May 2010, several tornadoes formed near the campus while OU researchers were operating OU-PRIME in a sector scanning mode, providing polarimetric radar data with unprecedented resolution and quality. In this article, the environmental conditions leading to the 10 May 2010 outbreak will be described, an overview of OU-PRIME will be provided, and several examples of the data and possible applications will be summarized. These examples will highlight supercell polarimetric signatures during and after tornadogenesis, and they will describe how the polarimetric signatures are related to observations of reflectivity and velocity.

A Dual-Polarization Radar Hydrometeor Classification Algorithm for Winter Precipitation

“…Thus, our HCA is designed for stratiform winter precipitation. We explain our methodology with a freezing rain case study using the C-band University of Oklahoma Polarimetric Radar for Innovations in Meteorology and Engineering (OU-PRIME) radar in Norman, Oklahoma (Palmer et al 2011). The nearby soundings for this event are shown in Fig.…”

“…This winter HCA was tested on four different polarimetric radars spanning three different frequencies: C-band OU-PRIME (Palmer et al 2011) and X-band Collaborative Adaptive Sensing of Atmosphere (CASA) radars in central Oklahoma (McLaughlin et al 2009;Junyent et al 2010); an S-band Polarimetric Weather Surveillance Radar-1988 Doppler (WSR-88DP) in Wichita, Kansas; and the dual-wavelength X-and S-band CSU-CHILL radar in northern Colorado (Brunkow et al 2000). See the appendix for radar data postprocessing details.…”

Polarimetric radar observations of dust storms at C- and S-band

“…Because variance of Z DR and ρ hv are a function of the ρ hv magnitude, C-band data tend to be inherently noisier. Though one benefit may be a larger range of ρ hv values at C-band (Palmer et al 2011), the reduction in ρ hv also may make it difficult to distinguish meteorological and non-meteorological scatterers in C-band data (Kumjian and Ryzhkov 2008). In summary, the primary expected differences are that Z DR values should be higher and ρ hv values lower in many situations at C-band, compared to Sband.…”

A Dual-Wavelength Polarimetric Analysis of the 16 May 2010 Oklahoma City Extreme Hailstorm

“…Total damage costs from the storm are estimated to be hundreds of millions of dollars. The storm occurred in close proximity to the WSR-88D polarimetric prototype S-band radar (KOUN) and the C-band University of Oklahoma Polarimetric Radar for Innovations in Meteorology and Engineering (OU-PRIME; Palmer et al 2011) such that high-resolution dualpolarization data were obtained. Finally, we utilize abundant ground truth for this event to evaluate methods for hail sizing and suggest areas of improvement for polarimetric hail detection.…”