Volumetric streamflow forecasts issued by the the USDA-NRCS are available for Montana Rivers and streams starting in March of each water year. Issue dates are the 5th business day of each month from March through June.
There are a multitude of ways to view the forecasts for each point. The legacy table format can be found in the monthly update report, however, the forecasts can also be viewed in chart form to view the entire range of outcomes, and can also be seen in a spatial format to compare forecasts within a region. Links or interactive frames to view this data can be found below.
Monthly Forecasts - Graphical Format
Click here, or on the image belowto be directed to the tool which allows for viewing of forecasts for your river basin of interest. This format is the favorite of the SNOW program staff. It allows for easy viewing of all the exceedance forecasts issued for each point, and how the distribution of those forecasts relates to the 30 year average. Viewing the entire range, and distribution allows water users to consider multiple potential outcomes for their water management practices.
Shown below are all streamflow forecasts for the most recent forecast period. The date of the forecast and period selected can be seen in the legend. Water users can hover over an individual point for the forecasted percentage of average, or click on the point for more detailed statistics.
Displayed is the 50% exceedance forecast for each point. To view a range of exceedance probabilities for each forecast point, please see the monthly graphic listed above, or in the table format listed below.
Monthly Forecasts - Table Format
Select state and basin of interest for the most recent date published. Select "Forecast" and a .pdf will download with the information for your selection(s). Please remember, forecast tables will only be available for most Montana basins on March 1st through June 1st.