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Regional Snowfall Index (RSI)

Published by DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce | National Oceanic and Atmospheric Administration, Department of Commerce | Catalog Last Checked: April 12, 2026 at 09:12 PM | Dataset Last Updated: June 01, 2014 at 12:00 AM
The Regional Snowfall Index (RSI) is an index of 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. NCEI 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 (the precursor to NCEI) 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.

Resources

9 resources available

  • NCEI Dataset Landing Page

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  • NCEI Climate Data Online Map Server

    TEXT/HTML
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  • NCEI ArcGIS REST Services Directory

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  • Direct Download for Surface Snow Products

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  • The Regional Snowfall Index (RSI) web page.

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  • Regional Snowfall Impact Scale

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    Download

  • The Regional Snowfall Index (Published paper)

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    Download

  • Northeast Snowfall Impact Scale

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    Visit Page

  • Global Change Master Directory (GCMD) Keywords

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Complete Metadata
@type dcat:Dataset
accessLevel non-public
contactPoint 
                                            {
  "fn": "DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce",
  "@type": "vcard:Contact",
  "hasEmail": "mailto:ncei.orders@noaa.gov"
}
describedByType application/octet-steam
description The Regional Snowfall Index (RSI) is an index of 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. NCEI 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 (the precursor to NCEI) 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.
distribution 
                                            [
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    "description": "Dynamic GIS mapping application to locate stations and data for selected layers.",
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    "@type": "dcat:Distribution",
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    "@type": "dcat:Distribution",
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    "description": "Background, description, RSI maps and data values.",
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    "@type": "dcat:Distribution",
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    "format": "PDF",
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    "description": "PDF file of science paper",
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    "describedByType": "application/octet-stream"
  },
  {
    "@type": "dcat:Distribution",
    "title": "Northeast Snowfall Impact Scale",
    "accessURL": "https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ncdc:C00453/html",
    "mediaType": "text/html",
    "description": "A precursor to the Regional Snowfall Index.",
    "describedByType": "application/octet-stream"
  },
  {
    "@type": "dcat:Distribution",
    "title": "Global Change Master Directory (GCMD) Keywords",
    "accessURL": "https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords",
    "mediaType": "text/html",
    "description": "The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords.",
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]
identifier https://data.noaa.gov/waf/NOAA/NESDIS/ncei/aim/iso/xml/C00465.xml
issued 2011-01-01T00:00:00.000+00:00
keyword 
                                            [
  "Earth Science > Atmosphere > Precipitation > Solid Precipitation > Snow",
  "Earth Science > Terrestrial Hydrosphere > Snow/Ice > Snow Depth",
  "Earth Science > Human Dimensions > Natural Hazards > Meteorological Hazards",
  "Land Surface",
  "Continent > North America > United States Of America",
  "Vertical Location > Land Surface",
  "DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce",
  "DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce"
]
language 
                                            []
license https://creativecommons.org/publicdomain/zero/1.0/
modified 2014-06-01T00:00:00.000+00:00
publisher 
                                            {
  "name": "DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce",
  "@type": "org:Organization"
}
references 
                                            [
  "https://www.ncei.noaa.gov/pub/data/metadata/documents/C00465_squires-lawrimore-paper.pdf",
  "http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-13-00101.1",
  "https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ncdc:C00453/html"
]
rights otherRestrictions
spatial -65.0,30.0,-100.0,50.0
temporal 1900-01-01T00:00:00+00:00/1900-01-01T00:00:00+00:00
title Regional Snowfall Index (RSI)

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