Western U.S. Streamflow Forecasts

Currently, streamflow forecasts are made near the beginning of each month using the Variable Infiltration Capacity hydrologic model, applied for daily simulation of western U.S. hydrology at 1/8 degree grid resolution. The daily ensemble outputs of these simulations are summarized as monthly hydrograph distribution plots (accessed from the map(s) below), and as summer runoff period anomalies, or "Seasonal Volume Forecasts", where the summer runoff period is either April-September or April-July, for the various forecast types (e.g., ESP, CPC, climate model-based).

Tabular forecast summaries and links to model output are also provided below. For more information on the methods used, see the description on the Research page.

Seasonal Volume Forecasts

The clickable map below summarizes the current ESP/CPC volume forecasts for the streamflow simulation locations that are currently active. Clicking on a point launches a window showing the monthly streamflow hydrograph distributions for each type of forecast (e.g., ESP, CPC). Below the hydrographs, the prior evolution of selected basin-averaged hydrometeorological variables is also shown. Tabular results for all volume forecasts are available from links at the bottom of the page.

Summer Streamflow: ESP CPC           Next 6 months Streamflow: ESP CPC

Station ID Station Name Ensemble Median % of Average Ensemble Median % of Median Ensemble Average % of Average Forecast Period Quick Links to Current Spatial Conditions      Soil Moisture      Snow Water Equivalent      SNOTEL / ASP(BC)

Summary Statistics

Volume Forecast Statistics

The links below present a small set of summary statistics describing the flow forecasts at each location. Currently, the only statistic shown is the forecast percent of average climatological flow (based on 1960-99) at three percentiles: 0.10, 0.50 (median) and 0.90. The statistics refer, for now, to the unconditional and ENSO-conditioned ESP forecast ensembles.

Ensemble Data