2005 Annual Report 4d.Progress report. This report serves to document research conducted under a reimbursable agreement between the ARS Hydrology and Remote Sensing Laboratory and the National Aeronautics and Space Administration. Additional details of research can be found in the report for the parent project 1265-13610-026-00D entitled, "INTEGRATING REMOTE SENSING, CLIMATE AND HYDROLOGY FOR EVALUATING WATER, ENERGY AND CARBON CYCLES." The project seeks to develop innovative strategies for integrating spaceborne soil moisture retrievals with hydrologic models to improve the quality and lead time of hydrologic forecasts before and during large-scale flooding events. Using an adaptive filtering techniques, remotely sensed soil moisture imagery have been demonstrated to add value to forecasts of flood peak and magnitude during a January 2004 flooding event in the Queensland region of Australia. In addition, multi-year studies of 30 intermediate-scale basins in the United States southern great plans has demonstrated that remotely-sensed soil moisture imagery adds marginal skill be our ability to forecast land surface response to precipitation - especially during high-flow events. Two peer-review manuscripts have been written based on these results. During the coming year, work will focus on formalizing data assimilation and modeling techniques within a flood-forecasting system.