Monitoring snowpack conditions in vast mountainous terrain is critical for western water managers. Though products like the United States Department of Agriculture’s (USDA) SNOTEL and NOAA’s SNODAS currently provide information on snow-water equivalent (SWE), the amount of water contained in the snowpack, significant gaps remain. The Western Water Assessment (WWA), a CPO Regional Integrated Sciences and Assessments team, is now distributing an experimental research product that compliments the official USDA and NOAA products and provides detailed near-real-time estimates of SWE for the Intermountain West region. WWA shares the information through four spring-time reports that include: maps of estimated SWE for the entire region, selected sub-regions and different elevations; tabular SWE data and water volume estimates for each basin; comparisons with NOAA’s SNODAS spatial SWE estimates; and descriptions of the methods used for producing the spatial SWE product. If the product performs well, there may be an opportunity to transition it to operations.
In 2015, the WWA convened a workshop to consider the state of snowpack monitoring in the Intermountain West region (Colorado, Utah, and Wyoming) and the application of the experimental research product, which had been applied in the Sierra Nevada Mountains for California water managers. After beta-testing in 2018, WWA began distributing the experimental product. The 2018 beta-tests found that water managers were excited to use the new product to improve streamflow forecasts and to ground-truth, scenario plan, and compare other sources of information.
The product is based on SNOTEL and CoCoRaHS SWE data, snow cover data from MODIS satellite images, physiographic information, and reconstructed historical daily SWE pattern. It was developed by Noah Molotch (Colorado University INSTAAR, CWEST and WWA), Leanne Lestak and Keith Musselman.