This data release contains data used within the PRMS CONUS Futures Portal including descriptions of data layers in the Uncertainty Analysis section, reference model performance at stream gage locations, and model performance metrics for climate model based simulations. 1) The description of variables available in the Uncertainty Analysis tab include variable short name, variable long name, description, methodology, caveats, additional user information, and references; 2) stream gage validation metrics calculated at 8720 USGS stream gages for 1951-2009 with observed flow compared to reference model flow (Maurer). Information provided at each gage location includes corresponding PRMS segment ID, reference or non-reference gage status, drainage basin area comparison, Nash-Sutcliffe Efficiency (NSE), Percent Bias (Pbias), Root Mean Standard Deviation Ratio (RSR), a cumulative gage score summing NSE, Pbias, and RSR suitability, and Disturbance Index (DI); and 3) ensemble model performance metrics calculated using the Kolmogorov-Smirnov statistical test. Values are provided for the reference model simulation versus the historical global climate model simulations (1976-2005) and for the historical versus future global climate model simulations at three future time periods (2015-2045, 2046-2075, and 2071-2100) versus the historical period (1976-2005).