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Western United States Streamflow Forecasts

Experimental, real-time twelve month forecasts of western United States hydrologic conditions are available through the University of Washington's West-Wide Seasonal Streamflow Forecasting Project. These forecasts, which are updated monthly, are created for the Columbia, Colorado, and Upper Rio Grande River basins, the Great Basin, and California. Among the products provided are:

  • monthly streamflow forecast ensembles for 15 locations in the Columbia River basin and 20 locations in the Snake River basin (Figures 1 and 2);
  • spatial distributions of forecasted snow water equivalent, soil moisture and runoff; and
  • nowcasts of spatially-distributed snow water equivalent and soil moisture conditions

The forecasts are developed using a macroscale hydrologic model and are based on three sources:

  • the Ensemble Streamflow Prediction (ESP, formerly Extended Streamflow Prediction) method conditioned on ENSO and PDO states;
  • ensemble forecasts downscaled from several climate models; and
  • ensemble forecasts based on the 12-month lead-time Climate Prediction Center Outlooks.

The streamflow forecasts, spatial plots of hydrologic conditions (current and forecasted conditions), forecast data, and other information are available on the West-Wide Seasonal Streamflow Forecasting Project web site.

Columbia River Basin Streamflow Forecast Points [map]

Figure 1 Available Columbia River basin streamflow forecast points


Columbia River Basin Streamflow Forecast Points [map]

Figure 2 Available Snake River basin streamflow forecast points


This experimental effort is primarily funded by NOAA's Climate Program Office, the IRI/ARCS Regional Applications Project, and the NASA Seasonal-to-Interannual Prediction Project (NSIPP).

Page last updated 2.21.06