Retrieval and Quantitative Evaluation of Three-Dimensional Winds in Severe Convection with Multistatic Radar

Abstract Multistatic weather radar systems have the potential to provide three-dimensional wind information from both operational and research radars, given that each radar provides a distinct Doppler velocity measurement. A prototype multistatic network consisting of two passive receivers and the nearby operational KTLX Weather Surveillance Radar-1988 Doppler (WSR-88D) has been deployed in the Oklahoma City metropolitan area. To achieve sufficiently precise Doppler frequency estimates while reducing system cost, transmitter/receiver synchronization is accomplished through direct-path measurements of the WSR-88D’s sidelobe radiation. Several cases of observed severe convection are presented, including instances of quasi-linear convective systems (QLCSs) and supercells. Multi-Doppler retrievals performed with the multistatic data are shown to resolve important structures in the three-dimensional wind fields, including mesocyclones. Quantitative analysis and evaluation of the retrievals are performed by comparison with simultaneous multi-Doppler retrievals done with monostatic radar data only, along with direct numerical comparison to independent radial velocity measurements. For the case analyzed under this framework, the multistatic system yields a mean error of −1.3 m s −1 , compared to −2.8 m s −1 for the monostatic system. In addition, retrieved vertical velocities from the multistatic system are compared to a locally deployed vertically pointing radar providing additional system validation and error quantification for the vertical velocity field, where the multistatic system provides a stark improvement in retrieved vertical velocity over the monostatic system. This relatively low-cost technology has the potential to significantly expand the observing capabilities of the operational WSR-88D radar network. Significance Statement This study explores the performance of a novel, low-cost weather radar network in producing three-dimensional winds compared to conventional radar networks. Several cases of observed severe weather show that this novel system performs as well as or better than conventional radar systems. Given these results, it is suggested that this system could be adopted for operational use, as three-dimensional wind information is useful for severe weather forecasting.