Recently, the Snow Survey and Water Supply Forecasting (SSWSF) Program published new 30-year hydroclimatic normal values or “normals” for snowpack and precipitation at western U.S. monitoring stations. This information serves as a benchmark for assessing water supply conditions and is used by producers, natural resource managers and the research community.
Each decade the SSWSF Program calculates the median and average over a 30-year period to provide this data. This update shifts the reference period from the 1981-2010 period to the 1991-2020 period and includes new values for nearly 700 automated SNOTEL (snow telemetry) stations and over 900 snow course measurements at sites managed by NRCS. Data from SNOTEL stations help inform decisions for water managers, reservoir operators, producers, recreationists, and other groups.
Also included in the update are 1991-2020 medians and averages for external agency reservoir storage and streamflow volumes, used for water supply forecasting across the west.
To view the new data and to learn more about this update, visit the National Water and Climate Center Normals Website. You may also view the NWCC Interactive Map.