Examining Meteorological Benefits of Rapid-Scan, Fully Digital Phased Array Radar Observations for Detecting Tornado Formation and Intensification

Abstract

Abstract This study focuses on the application of phased array radars (PARs) to observe tornadoes and their formation. PAR technology for meteorological applications is maturing and may become a valuable tool for the meteorological community. A fully digital PAR offers a range of benefits including adaptive scanning techniques, higher temporal resolution especially via radar imaging modes, and denser vertical sampling to allow for more complete observations of severe hazard structure and evolution. To best understand the benefits of such a system, synthetic PAR observations are generated from archived mobile rapid-scan observations collected by the Rapid X-Band Polarimetric (RaXPol) radar to emulate typical operational radar ranges and PAR-enabled scanning strategy effects. In this study, a synthetic PAR data tool is applied to two tornadic cases (24 May 2011 El Reno, Oklahoma, tornado and the 24 May 2016 Dodge City, Kansas, tornadoes) and one nontornadic case (17 April 2013). Results indicate that, despite increasing standoff ranges and using vertical imaging, a PAR can still observe a similar mode of tornadogenesis [i.e., nondescending tornadic vortex signature (TVS)] as traditional mobile systems but with a slight delay in observing intensification at increasing standoff ranges and reduced change in measured intensity. The PAR-enabled vertical imaging mode does not eliminate our ability to identify the TVS at different spoiling factors, but changes to the structure of the TVS may have operational implications. We hope that the improved understanding of meteorological benefits from these synthetic PAR data can provide useful insight for fully digital PAR radar placement and warning operations. Significance Statement The purpose of this study is to understand the benefits of future radars with faster, more advanced phased array technology. Using mobile radar data, we simulate phased array radar observations for nine tornadic cases and one nontornadic case. Using rapid-scan updates at long distances, we observed that tornado formation and intensification characteristics align with existing literature but exhibit slight delays and reduced intensity. Vertical imaging (simultaneous observations in elevation) does not affect velocity signature detectability but broadens signatures, making intensification less apparent. While our results highlight the utility of phased array radar observations for tornadoes, they also reveal potential detection challenges. Future work should examine additional scanning techniques and variables to assess observational impacts further.