This article summarizes research and risk reduction that will inform acquisition decisions regarding NOAA’s future national operational weather radar network. A key alternative being evaluated is polarimetric phased-array radar (PAR). Research indicates PAR can plausibly achieve fast, adaptive volumetric scanning, with associated benefits for severe-weather warning performance. We assess these benefits using storm observations and analyses, observing system simulation experiments, and real radar-data assimilation studies. Changes in the number and/or locations of radars in the future network could improve coverage at low altitude. Analysis of benefits that might be so realized indicates the possibility for additional improvement in severe-weather and flash-flood warning performance, with associated reduction in casualties. Simulations are used to evaluate techniques for rapid volumetric scanning and assess data quality characteristics of PAR. Finally, we describe progress in developing methods to compensate for polarimetric variable estimate biases introduced by electronic beam-steering. A research-to-operations (R2O) strategy for the PAR alternative for the WSR-88D replacement network is presented.

To fulfill the evolving observational needs of the National Weather Service (NWS), future weather radar systems will have to meet demanding requirements. Designing such systems will likely involve trade-offs between system cost and operational performance. A potential cost driver for future weather radars that could cause significant data-quality impacts on forecasters is the required angular resolution and sidelobe performance, which are mainly dictated by the antenna radiation pattern. Typical antenna radiation patterns can be characterized by the width of the main lobe and their sidelobe levels, which are traditionally measured across the azimuthal and elevation dimensions. In this work, we study the impact of increasing sidelobe levels on NWS forecasters’ data interpretation during warning operations. The resulting impact model can be used by decision-makers to better understand the cost–benefit trade-offs inherent in any radar system design.