Regional Snowfall Index (RSI)

Metadata Updated: February 7, 2018

NOAA's National Climatic Data Center is now producing the Regional Snowfall Index (RSI) for significant snowstorms that impact the eastern two thirds of the U.S. The RSI ranks snowstorm impacts on a scale from 1 to 5, similar to the Fujita scale for tornadoes or the Saffir-Simpson scale for hurricanes. NCDC has analyzed and assigned RSI values to over 500 storms going as far back as 1900. New storms are added operationally. As such, RSI puts the regional impacts of snowstorms into a century-scale historical perspective. The RSI differs from other indices because it includes population. RSI is based on the spatial extent of the storm, the amount of snowfall, and the juxtaposition of these elements with population. The area and population are cumulative values above regional specific thresholds. For example, the thresholds for the Southeast are 2", 5", 10", and 15" of snowfall while the thresholds for the Northeast are 4", 10", 20", and 30" of snowfall. Population information ties the index to societal impacts. Currently, the index uses population based on the 2000 Census. The RSI is an evolution of the Northeast Snowfall Impact Scale (NESIS) which NCDC began producing operationally in 2005. While NESIS was developed for storms that had a major impact in the Northeast, it includes the impact of snow on other regions as well. It can be thought of as a quasi-national index that is calibrated to Northeast snowstorms. By contrast, the RSI is a regional index; a separate index is produced for each of the six NCDC climate regions in the eastern two-thirds of the nation. The indices are calculated in a similar fashion to NESIS, but our experience has led us to propose a change in the methodology. The new indices require region-specific parameters and thresholds for the calculations. For details on how RSI is calculated, see Squires et al. 2011.

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Metadata Date April 24, 2017
Metadata Created Date August 8, 2016
Metadata Updated Date February 7, 2018
Reference Date(s) January 1, 2011 (publication), June 1, 2014 (revision)
Frequency Of Update asNeeded

Metadata Source

Harvested from NOAA CSW Harvest Source

Graphic Preview

RSI map example for snowstorm events.

Additional Metadata

Resource Type Dataset
Metadata Date April 24, 2017
Metadata Created Date August 8, 2016
Metadata Updated Date February 7, 2018
Reference Date(s) January 1, 2011 (publication), June 1, 2014 (revision)
Responsible Party DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce (Point of Contact)
Contact Email
Access Constraints Cite this dataset when used as a source., NCEI cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NCEI makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Bbox East Long -65.0
Bbox North Lat 50.0
Bbox South Lat 30.0
Bbox West Long -100.0
Coupled Resource
Frequency Of Update asNeeded
Graphic Preview Description RSI map example for snowstorm events.
Graphic Preview File
Graphic Preview Type PNG
Guid gov.noaa.ncdc:C00465
Harvest Object Id b880b849-87af-499c-9aaf-616ca417c2e8
Harvest Source Id 2aed8e29-fc5b-4cde-aa66-fb1118fd705e
Harvest Source Title NOAA CSW Harvest Source
Metadata Language
Metadata Type geospatial
Progress underDevelopment
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 1900-01-01

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