Streamflow Forecasts - Nevada and Eastern Sierra


A streamflow forecast is a prediction of water volume that will flow past a point on a stream during a specified season, typically in the spring and summer. These forecasts help water managers and farmers prepare for the spring runoff. The Natural Resources Conservation Service (NRCS) issues water supply forecasts for hundreds of points in the western United States near the first of the month between January and June each year and at other times as requested. In Nevada and Eastern California a full set of streamflow forecasts are issued shortly after the first of the month. A smaller sub-set of forecasts are typically issued mid-month. The below products present streamflow forecasts as tables, graphics and maps.

To learn more about how streamflow forecasts are made and how to interpret them, choose from a general overview or a technical description.

Example image of streamflow forecast table

Official Streamflow Forecast Tables

Issued shortly after the first of the month. A smaller sub-set of forecasts are typically issued mid-month.

Example Image of Streamflow Forecast Graphic

Official Streamflow Forecast Chart

For an explanation about how to use this tool. Click here

This chart is also useful to compare previous year's forecasts to observed streamflow for verification. See the help link above for more information.

Example Image of Interactive Map Streamflow Forecasts

Official Streamflow Forecast Map Links

50% exceedance forecast for most recent forecast publication

Example  Daily Exceedance Guidance Forecasts Graph

Unofficial Daily Streamflow Forecasts

Daily Water Supply Forecast products are useful to track how recent weather events, such as wet or dry periods, change streamflow forecasts between official first of month and mid-month forecasts. Daily Water Supply Forecast products should not be used as official NRCS forecasts. These are a completely automated set of products based on provisional SNOTEL snow water and precipitation data.