Regional Snowfall Index

February 9-11, 1973, Regional Snowfall Index Map

In a collaborative effort, scientists from NCDC and Rutgers University have created an index to improve understanding of the regional impacts associated with snowstorms in the United States. Described in “The Regional Snowfall Index,” published as an Early Online Release in Bulletin of the American Meteorological Society, the Regional Snowfall Index (RSI) builds upon the success and lessons learned from the popular Northeast Snowfall Impact Scale.

RSI produces separate indices for six regions in the eastern two-thirds of the nation, ranking snowstorm impacts on a scale from 1 to 5, similar to the Enhanced Fujita scale for tornadoes or the Saffir–Simpson scale for hurricanes. These ranks are based on snowfall amount within the region’s borders, spatial extent of the storm, and the relationship of these elements to the area’s population, which allows them to account for both regional variations in snowfall patterns and how the amount of snow disrupts regions of the country differently.

The scientists have calculated RSI values for almost 600 snowstorms that occurred between 1900 and 2013, which provides a historical perspective of the magnitude and frequency of snowstorms. By adding a regional component to reporting on snowfall impacts, the RSI not only helps local officials understand the impacts of each major snowstorm but also allows them to better prepare for future snowstorms.

Review the full paper, The Regional Snowfall Index, from the Bulletin of the American Meteorological Society

Access NCDC’s operational Regional Snowfall Index.