This project focused on assessing and identifying avenues to improve Reclamation’s current temperature modeling use of seasonal predictions of input meteorology, as well as on several related investigations. The effort developed a new overview for Reclamation and stakeholders of the methods and performance of the meteorologic forecasts currently being applied for water temperature simulation. To facilitate this effort, the current spreadsheet-based Local Three-Month Temperature Outlook (L3MTO) method was duplicated in a set of Python scripts, which were transitioned to Reclamation for potential use in operations at Shasta Lake and other California facilities. These scripts make hindcast analyses feasible and provide flexibility in examining alternative inputs and ease in conducting supporting analyses. The scripts were used to test or demonstrate several variations on the approach, including using Sub-seasonal to Seasonal (S2S) forecasts from other sources, and to assess the skill of the approach and its likely upper limits of performance. In particular, the work showed that the temperature model input forecasts had mean monthly skill in the first lead month of the forecast and indicated potential for improvement through further development of the input climate forecasts as well as using alternatives to the climate-conditioned deterministic analog selection method. The project also implemented a California-wide daily gridded meteorological analysis using a tool called the Gridded Meteorological Ensemble Tool (GMET), and a demonstration of a linked Structure for Unifying Multiple Modeling Alternatives-mizuRoute-River Basin Model (SUMMA-mizuRoute-RBM) model for the Shasta and Trinity Lake drainage areas, demonstrating the feasibility of a distributed strategy for stream temperature simulation and potentially prediction.

This data release contains 16 variables from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS) version 1.1 modeling application forced with CONUS404-BA (Markstrom and others, 2024) from January 1980 through September 2021 that are summarized to a monthly time step and a twelve-digit hydrologic unit code for the spatial extent of the conterminous United States. The following fluxes and storages are included: total monthly precipitation, evapotranspiration, lateral flow, surface runoff, interflow, recharge, groundwater flow, and the average monthly snow water equivalent, interflow storage, groundwater storage, total storage, and soil moisture. These data can be found in the “huc12_monthly_nhmprms_conus404ba_1980_2021.nc” file. Additionally, two supplementary files are also included in this data release. The first file (“weights_hru_to_huc12_nhmprms_conus404ba.csv”) contains the spatial weights or fraction that is used to “weight” the modeling output in the area-weighting process. The second file (“summed_weights_per_huc12_nhmprms_conus404ba.csv”) contains the total fractional area within each twelve-digit hydrologic unit code that is covered by the modeling output and is important for filtering results in the data file (where a fractional coverage may be less than one).

This data release contains 16 variables from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS) version 1.1 modeling application forced with CONUS404-BA (Markstrom and others, 2024) from January 1980 through September 2021 that are summarized to a monthly time step and a twelve-digit hydrologic unit code for the spatial extent of the conterminous United States. The following fluxes and storages are included: total monthly precipitation, evapotranspiration, lateral flow, surface runoff, interflow, recharge, groundwater flow, and the average monthly snow water equivalent, interflow storage, groundwater storage, total storage, and soil moisture. These data can be found in the “huc12_monthly_nhmprms_conus404ba_1980_2021.nc” file. Additionally, two supplementary files are also included in this data release. The first file (“weights_hru_to_huc12_nhmprms_conus404ba.csv”) contains the spatial weights or fraction that is used to “weight” the modeling output in the area-weighting process. The second file (“summed_weights_per_huc12_nhmprms_conus404ba.csv”) contains the total fractional area within each twelve-digit hydrologic unit code that is covered by the modeling output and is important for filtering results in the data file (where a fractional coverage may be less than one).

This data release contains three variables from the National Hydrologic Model Infrastructure with the Precipitation-Runoff Modeling System (NHM-PRMS) version 1.1 modeling application forced with CONUS404-BA (Markstrom and others, 2024) from January 1st, 1980 through September 25th, 2021 that are summarized to a twelve-digit hydrologic unit code for the spatial extent of the conterminous United States at a daily timestep. The three variables presented here are snow water equivalent, actual evapotranspiration, and soil moisture fraction. There are three netCDF files of daily, modeled data; one for each of the following variables: actual evapotranspiration - "huc12_daily_nhmprms-conus404ba_actet.nc", soil moisture fraction - "huc12_daily_nhmprms-conus404ba_soil_moisture_fraction.nc", and snow water equivalent - "huc12_daily_nhmprms-conus404ba_pkwater_equiv.nc". Additionally, two supplementary files are also included in this data release. The first file (“weights_hru_to_huc12_nhmprms_conus404ba.csv”) contains the spatial weights or fraction that is used to “weight” the modeling output in the area-weighting process. The second file (“summed_weights_per_huc12_nhmprms_conus404ba.csv”) contains the total fractional area within each twelve-digit hydrologic unit code that is covered by the modeling output and is important for filtering results in the data file (where a fractional coverage may be less than one).

These datasets are continuous parameter grids (CPG) of total annual precipitation data for the years 2000 through 2016 in the Pacific Northwest. Source precipitation data was produced by the PRISM Climate Group at Oregon State University.

These datasets are continuous parameter grids (CPG) of total annual precipitation data for the years 2000 through 2016 in the Pacific Northwest. Source precipitation data was produced by the PRISM Climate Group at Oregon State University.

This data release contains accumulated precipitation data from the CONUS404 climate forcing variable subset for hydrologic models, downscaled to 1 km and bias-adjusted for precipitation and temperature (CONUS404-BA; Zhang and others, 2024) from January 1980 through September 2021 that is summarized to a monthly time step and a twelve-digit hydrologic unit code for the spatial extent of the conterminous United States. These data can be found in the “huc12_monthly_conus404ba_WY1980_WY2021.nc” file. Additionally, one supplementary file is also included in this data release. The additional file (“weights_grid_to_huc12_conus404ba.csv”) contains the spatial weights, or fraction, that is used to “weight” the source data in an area-weighting process.

This data release contains accumulated precipitation data from the CONUS404 climate forcing variable subset for hydrologic models, downscaled to 1 km and bias-adjusted for precipitation and temperature (CONUS404-BA; Zhang and others, 2024) from January 1980 through September 2021 that is summarized to a monthly time step and a twelve-digit hydrologic unit code for the spatial extent of the conterminous United States. These data can be found in the “huc12_monthly_conus404ba_WY1980_WY2021.nc” file. Additionally, one supplementary file is also included in this data release. The additional file (“weights_grid_to_huc12_conus404ba.csv”) contains the spatial weights, or fraction, that is used to “weight” the source data in an area-weighting process.