Supporting Advancement in Weather and Water Prediction in the Upper Colorado River Basin: The SPLASH Campaign.

SIGNIFICANCE STATEMENT: Water is a limited and critical resource in the western United States. To protect water access for millions of people and ecosystems, and to preserve our ability to irrigate millions of acres of cropland, policymakers and water managers require advanced weather and water prediction systems. To improve these forecast systems in high-altitude complex terrain, the National Oceanic and Atmospheric Administration (NOAA) has deployed instrumentation in the East River watershed of the Upper Colorado River basin as part of the Study of Precipitation, the Lower Atmosphere, and Surface for Hydrometeorology (SPLASH). SPLASH observations are being used to advance fundamental understanding of mountain weather and water and to advance predictive capabilities across weather and climate time scales. Water is a critical resource that causes significant challenges to inhabitants of the western United States. These challenges are likely to intensify as the result of expanding population and climate-related changes that act to reduce runoff in areas of complex terrain. To better understand the physical processes that drive the transition of mountain precipitation to streamflow, the National Oceanic and Atmospheric Administration has deployed suites of environmental sensors throughout the East River watershed of Colorado as part of the Study of Precipitation, the Lower Atmosphere, and Surface for Hydrometeorology (SPLASH). This includes surface-based sensors over a network of five different observing sites, airborne platforms, and sophisticated remote sensors to provide detailed information on spatiotemporal variability of key parameters. With a 2-yr deployment, these sensors offer detailed insight into precipitation, the lower atmosphere, and the surface, and support the development of datasets targeting improved prediction of weather and water. Initial datasets have been published and are laying a foundation for improved characterization of physical processes and their interactions driving mountain hydrology, evaluation and improvement of numerical prediction tools, and educational activities. SPLASH observations contain a depth and breadth of information that enables a variety of atmospheric and hydrological science analyses over the coming years that leverage collaborations between national laboratories, academia, and stakeholders, including industry. [ABSTRACT FROM AUTHOR]