High Resolution Radar Quantitative Precipitation Estimation in the San Francisco Bay Area: Rainfall Monitoring for the Urban Environment

Abstract

 An X-band radar system was deployed in Santa Clara, CA from February through May 2016 to support the National Weather Service in the event of potential flooding during one of the largest El Niños on record and to provide better understanding of rainfall processes occurring in the Bay Area. The system was also used to provide high quality precipitation estimation (quantitative precipitation estimation - QPE) for Santa Clara’s urban hydrologic modeling system. Although the Bay Area has coverage from the NEXRAD operational radar network, the combination of topographic influences and proximity to a maritime environment provide unique QPE challenges in this urban region. The X-band radar provided high quality rainfall estimates that performed better than NEXRAD, demonstrating the added value of the X-band system. High resolution rainfall monitoring systems in urban regions also provide a host of benefits across different sectors of the economy, including flood damage mitigation, water quality, water supply, and transportation.