Intercomparisons of Radial Velocity Signatures from Initial All-Digital Horus PAR Observations with Fixed-Site Weather Radars

Rapid-scan observations of radial velocity signatures (e.g., tornadic vortex signatures) can have great utility in an operational setting. For example, the Phased Array Radar Innovative Sensing Experiment (PARISE) studies using National Weather Radar Testbed (NWRT) PAR data generally found increased lead-time and confidence in tornado warnings. An all-digital PAR network could further enable the study and operational detection of tornadoes through not only vertically dense, rapid-scan volumetric capabilities but also leveraging fully adaptive scanning capabilities and PAR-enabled scanning strategies (e.g., imaging). While a limited number of PAR datasets of supercells and tornadoes exist, until recently, no platform with an all-digital beamformer existed to evaluate the full range of PAR options available for a future operational network. With support from the NOAA National Severe Storms Laboratory (NSSL), the University of Oklahoma’s Advanced Radar Research Center has developed Horus—the first all-digital, polarimetric, S-band mobile PAR. This mobile radar platform will serve as an additional proof of concept of a future operational PAR network with its all-digital beamforming capabilities.

In this study, volumetric observations collected by Horus are analyzed, including data from 19 April 2023 where supercells exhibiting rotation were observed across central Oklahoma as well as suspected tornadogenesis failure near Moore, Oklahoma. The novel dataset will feature the first Horus deployments to collect vertically dense, volumetric updates with 360 degree array rotation on the order of ~30 s. With plans to collect additional data throughout the spring 2023 convective season in Oklahoma, these data will provide the initial results for analysis of radial velocity signatures from Horus. Intercomparisons will be done with KTLX, PX-1k, and other nearby radars to evaluate Horus’s data quality. As one means of comparing the datasets, intercomparisons will be done to match the cross-beam resolution of Horus and nearby radars. The dataset can also serve as an input to provide initial results for velocity-based multi-radar multi-sensor (MRMS) algorithms such as rotation tracks. These initial observations and results from Horus serve as motivation to further assess the benefits and utility of all-digital, polarimetric PAR observations (with PAR-enabled scanning strategies expected by year’s end) of supercells and tornadoes as well as develop future scanning strategies tailored to high-impact weather events.