NOAA's National Snow Analyses

TitleNOAA's National Snow Analyses
Publication TypeConference Proceedings
Year of Conference2006
AuthorsCarroll, T., Cline D., Olheiser C., Rost A., Nilsson A., Fall G., Bovitz C., and Li L.
Conference Name74th Annual Western Snow Conference
Series TitleProceedings of the 74th Annual Western Snow Conference
Date PublishedApril 2006
PublisherWestern Snow Conference
Conference LocationLas Cruces, NM
KeywordsNOHRSC, numerical weather prediction, snow model, airborne SWE, snow cover, snowpack

NOAA's National Operational Hydrologic Remote Sensing Center (NOHRSC) provides comprehensive, near real-time, snow observations, snow analyses, data sets, and map products in multiple formats at high spatial and temporal resolution for the Nation. The NOHRSC routinely ingests all of the electronically available, real-time, ground-based snow data, airborne snow water equivalent data, satellite areal extent of snow cover information, and numerical weather prediction (NWP) model forcings for the coterminous U.S. The NWP model forcings are physically downscaled from their native 13 km2 spatial resolution to a 1 km2 resolution for the CONUS. The downscaled NWP forcings drive the NOHRSC Snow Model (NSM) that includes an energy-and-mass-balance snow accumulation and ablation model run at a 1 km2 spatial resolution and at an hourly temporal resolution for the country. The ground-based, airborne, and satellite snow observations are assimilated into the model state variables simulated by the NSM using a Newtonian nudging technique. The principal advantages of the assimilation technique are (1) approximate thermal balance of the snowpack is maintained by the NSM, (2) physical processes are easily accommodated in the model, and (3) asynoptic data are incorporated at the appropriate times. The NSM is updated with assimilated snow observations and is used to generate a variety of snow products that combine to form NOAA's NOHRSC National Snow Analyses (NSA). The NOHRSC NSA incorporate all of the information necessary and available to produce a best estimate of real-time snow cover conditions at 1 km2 spatial resolution and hourly temporal resolution for the country.