Most of the annual streamflow in the western United States originates as snowfall that has accumulated in the mountains during the winter and early spring. As snowpack accumulates each year, NRCS hydrologists measure the snow and estimate the runoff that will occur when it melts.
To predict this annual runoff, the Snow Survey & Water Supply Forecasting Program manages and maintains a comprehensive network of manually-measured snow courses and automated Snow Telemetry (SNOTEL) monitoring sites throughout the West. Administered by the National Water & Climate Center, the Program collects and distributes timely, quality-controlled snowpack, water supply, and soil climate data to users worldwide.
