A real-time hydrologic forecasting testbed operated during the IPHEX IOP. In preparation for the forecasting testbed, a benchmark project for intercomparion of hydrologic models was developed (H4SE) in the context of which all data necessary (GIS, atmospheric forcing, land-surface attributes, soil properties, etc) to implement and operate hydrologic models in four major SE river basins (the Savannah, the Catawba-Sandee, the Yadkin-Peedee and the Upper Tennessee) were analyzed and processed at hourly time-step and at 1 km2 resolution over a 5-year period (2007-2012). Data are currently available to all participants. The goal of H4SE is to facilitate implementation of hydrologic models in the IPHEX region to assess the use and improve the utility of satellite-based Quantitative Precipitation Estimates (QPE) for hydrologic applications.