Research and Development in Advancing Fluidless Snow Water Content Monitoring

The U.S. Department of Agriculture (USDA) has coordinated the cooperative effort in snow surveying and water supply forecasting in the Western States since 1935. This initially involved the Research and Development (R&D) of progressive snowpack monitoring techniques, eventually bringing automated measurements that transmitted data directly to their office. The advances in snowpack monitoring provided more reliable and timely forecasts vital for farmers, business owners, and communities. The technology that is currently used to continuously measure Snow Water Equivalent (SWE), the snow pillow, was developed in the 1960’s, over 50 years ago. The snow pillow has been the only reliable SWE sensor despite the inherent limitations. With limited improvements in SWE monitoring to date, Alpine Hydromet set out to develop technology towards bringing a better solution for operators. This summarizes the R&D of two SWE sensors that aim to phase out the traditional fluid snow pillow while developing more reliable and robust technologies; the Fluidless Snow Pillow (FSP) and Cosmic Ray Detector (CRD). This analysis presents an indepth analysis of comparative data from the winter of 2016-17 and 2017-18 (partial winter through April, 2018) as tested at the UC Berkeley Central Sierra Snow Laboratory (CSSL). (KEYWORDS: snow water content, snow pillow, fluidless snow pillow, cosmic ray)