2010 Annual Report 1a.Objectives (from AD-416) Develop improved instrumentation, methodologies and models for water supply forecasting in the western U.S. 1b.Approach (from AD-416) Work cooperatively with NRCS to address issues, needs, and problems as they arise each year. With NRCS guidance, ARS will develop a research plan, including objectives, milestones and deliverables for each year of the project. ARS will provide the site, technical support, data management and analysis, and will publish findings as appropriate. NRCS will participate in project planning, analysis and publication of results.Documents Reimbursable with NRCS. Log 32658. Formerly 5362-13610-006-11R (4/07). 3.Progress Report The objective of this project is to develop a new strategy for water supply forecasting, and to test and develop new and more effective simulation models that can be used by the National Water and Climate Center (NRCS) for water supply forecasting. ARS scientists at the Northwest Watershed Research Center (NWRC) have done extensive testing and validation on an updated version of the snow model to insure that it will be easier to use, and will be more readily applied by NRCS and others. NWRC has also tested several integrated models that couple snow, soil moisture, temperature, and groundwater. The coupled models account for how these are distributed in mountain basins; water is routed to the streams and streamflow is predicted. The project involves ARS, NRCS, and university scientists from University of Idaho, Boise State University, University of California, Duke University, Penn State University, as well as scientists from Canada and Europe. Research progress and status were reported via regular email, conference calls and several site visits to NRCS. The agreement was established in support of Objective 5 of the in-house project, the goal being to test and validate new instrumentation, databases, and model interfaces for use by the NRCS and other action agencies and potential users.