Noaa’s National Snow Analyses

NOAA’s National Operational Hydrologic Remote Sensing Center (NOHRSC) provides comprehensive, near real-time, snow observations, snow analyses, data sets, and map products used operationally across the Nation. The NOHRSC routinely ingests all electronically available, real-time, ground-based, airborne, and satellite snow observations along with numerical weather prediction (NWP) model forcings for the coterminous U.S. NWP model forcings are physically downscaled from their native 13 km to 1 km and used to drive an energy-and-massbalance snow model run at 1 km spatial resolution and hourly time-steps for the country. The snow observations are assimilated into the snow model state variables daily using a Newtonian nudging technique. The updated model state variables are used to generate a variety of snow products that form NOAA’s NOHRSC National Snow Analyses (NSA). The NOHRSC NSA incorporate all information necessary and available to produce a “best estimate” of real-time snowpack properties for the country. The NOHRSC NSA consist of multiple daily, operational, products that characterize realtime snowpack properties including snow water equivalent, snow depth, surface and internal snowpack temperatures, surface and blowing snow sublimation, and snowmelt for the CONUS. Snow products are distributed in a variety of formats including interactive maps, time-series, alphanumeric products (e.g., mean areal snow water equivalent on a hydrologic basin-by-basin basis), text and map discussions, map animations, and quantitative gridded formats. The oral presentation will discuss operational snow modeling and include time-lap and 3-D visualization animations of snowpack properties (e.g., snow water equivalent and internal snowpack temperatures), interactive maps, and data sets available at www.nohrsc.noaa.gov. NOAA’s National Snow Analyses represents the state-of-the-art of merging the theory of energy-balance snow modeling into the practice of generating a broad suite of snow products used operationally by thousands of federal, state, local, private-sector, and general public end users across the Nation.