Monthly ensemble outputs from the National Hydrologic Model Precipitation-Runoff Modeling System and the Weather Research and Forecasting model hydrologic modeling system for the conterminous United States, Alaska, Hawaii, and Puerto Rico for water years 2010–2020

The Integrated Water Availability Assessment uses an ensemble of outputs from two hydrologic models to assess water supply conditions. Results from the two models, the National Hydrologic Model Precipitation-Runoff Modeling System (NHM-PRMS) and Weather Research and Forecasting model hydrologic modeling system (WRF-Hydro) were averaged to create a single model ensemble. A unique instance of each model was developed specifically for this application. Each model was run at its native spatiotemporal resolution and converted to the subwatershed (12-digit hydrologic unit code; HUC12) spatial resolution and year-month temporal resolution for ensembling and assessment purposes. For NHM, the native spatiotemporal resolution is hydrologic response units (HRU), which have an average area of about 75 m2 at a daily time step. For WRF-Hydro, the native spatiotemporal resolution is a 250-m grid at an hourly timestep. The data in this release represent the mean between the results from of each model, by variable (hydrologic state or flux), at the HUC12, year-month resolution.