From CRREL to the 557th Weather Wing: Snow Assessments in Remote, Austere Watersheds

The Cold Region Research and Engineering Laboratory (CRREL) has produced bi-weekly snow assessments on an operational basis supporting the US Army Corps of Engineer (USACE) Reachback Operations Center (UROC) requests since 2005. The snow assessments provide information on snow impacted watersheds in remote and austere locations to the US military and a variety of other organizations. The CRREL Snow Assessment Team has worked closely with the Army's operational weather/climate support provider at the 14th and 16th Weather Squadron under the Air Force 557th Weather Wing (formerly Air Force Weather Agency, AFWA) to integrate the technology and procedures developed by CRREL for mapping the Snow Covered Area (SCA), estimating the total watershed Snow Water Equivalent (SWE), and presenting the information in an easily interpretable format within the 557th's operational baseline. CRREL developed a unique time domain filtering procedure that uses NASA SCA datasets from MODIS imagery to produce virtually cloud-free SCA maps. The initial steps have been taken to produce similar maps using VIIRS imagery. The SWE information is based on global gridded SWE estimates determined by National Snow and Ice Data Center (NSIDC) from Defense Meteorological Satellite Program (DMSP) passive microwave observations. CRREL's watershed-based analysis of passive microwave derived SWE minimizes the impact of known errors and maximizes user utility by presenting the data in a historical context. The assessments support a related spectrum of application: humanitarian needs, water resource evaluation, flood planning, hydropower forecasting, evaluating proposed engineering projects, and transportation. Currently the snow assessments are done for major watersheds in specific Areas of Interest but these procedures have the potential for global application.