; (2) developing an atmospheric river forecast system within the unified forecast system, and advancing next-generation coupled modeling systems, with the capability of providing seasonal to short-range atmospheric river forecasts that include forecast of snow accumulation and other hydrologic components; (3) advancing scientific understanding of the roles of atmospheric rivers in subseasonal to seasonal precipitation and probabilistic predictions at subseasonal and seasonal scales; (4) developing tools and improved forecast products to predict periods of active or inactive atmospheric river landfalls and inland penetration over the western United States with a focus on addressing stakeholder and public needs related to perceiving, comprehending, and responding to atmospheric river forecast improvements