The hydrometeorological observation network in California's russian river watershed development, characteristics, and key findings from 1997 to 2019

Abstract

The Russian River Hydrometeorological Observing Network (RHONET) is a unique suite of high-resolution in situ and remote sensing observations deployed over 20 years to address both scientific and operational gaps in understanding, monitoring, and predicting weather and water extremes on the United States' West Coast. It was created over many years by diverse organizations ranging from universities to federal, state, and local government agencies and utilities. Today, RHONET is a hybrid network with diverse observation sets aimed at advancing scientific understanding of physical processes driving extreme precipitation and runoff in the region. Its development is described, including the specific goals that led to a series of network enhancements, as well as the key characteristics of its sensors. The hydroclimatology of the Russian River area is described, including an overview of the hydrologic extremes and variability driving the scientific and operational needs in the region, from atmospheric river behavior and orographic precipitation processes to hydrologic conditions related to water supply and flooding. A case study of Lake Mendocino storage response to a landfalling atmospheric river in 2018 is presented to demonstrate the network's performance and hydrologic applications during high-impact weather events. Finally, a synopsis of key scientific findings and applications enabled by the network is provided, from the first documentation of the role of landfalling atmospheric rivers in flooding, to the occurrence of shallow nonbrightband rain, to the buffering influence of extremely dry soils in autumn, and to the development of forecast-informed reservoir operations for Lake Mendocino.