How is snow accumulation used to predict flooding?
The National Operational Hydrologic Remote Sensing Center (NOHRSC) is part of the National Weather Service (NWS). NOHRSC gathers satellite and airborne remote sensing information, such as snow cover, snow water equivalent, and surface air temperature, and displays this data using geographic information systems (GIS). The calculated SWE value is entered into a snow model to estimate the volume of snowmelt runoff. A rating curve is then used to relate the the total flowrate of the river to an estimated crest level. The NWS then uses this information to issue river and flood forecasts for the nation. I created the following schematic to illustrate the process used to predict crest levels for a given river. This process was utilized to predict the crest level of the Red River during the flood of 1997. Snow water equivalent (SWE) is equal to the amount of water that would exist should all the snow melt instantaneously. In general, 10 inches of snow would yield 1 inch of water. This rule of
