Regional Snowfall Index (RSI)

Regional Snowfall Index

browse graphicRSI map example for snowstorm events.
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.
  • Cite this dataset when used as a source.
  • NCEI DSI 3289_01
  • gov.noaa.ncdc:C00465
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Distributor Customer Engagement Branch
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
1-828-271-4800
ncei.orders@noaa.gov
Dataset Point of Contact User Services and Engagement Branch
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
+1 828-271-4800
ncei.orders@noaa.gov
Time Period 1900-01-01 to Present
Spatial Bounding Box Coordinates
N: 50.0
S: 30.0
E: -65.0
W: -100.0
Spatial Coverage Map
Dataset Information
General Documentation
Associated Resources
Publication Dates
  • publication: 2011-01-01
  • revision: 2014-06-01
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Under development - data is currently in the process of being created
Data Update Frequency As needed
Purpose This snowstorm impact rating scale factors in population, snowfall amounts, and storm coverage, thereby quantifying the societal impacts of a snowstorm for all major snowstorms since 1900. The RSI is important because of the need to place snowstorms and their societal impacts into a historical perspective on a regional scale. The index is useful for the media, emergency managers, the public and others who wish to compare regional impacts between different snowstorms.
Dataset Citation
  • Cite this dataset when used as a source.
Cited Authors
  • User Engagement and Services Branch
    DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce
Originators
  • User Engagement and Services Branch
    DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce
Publishers
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce
Theme keywords Global Change Master Directory (GCMD) Science Keywords
  • Earth Science > Atmosphere > Precipitation > Solid Precipitation > Snow
  • Earth Science > Terrestrial Hydrosphere > Snow/Ice > Snow Depth
  • Earth Science > Human Dimensions > Natural Hazards > Meteorological Hazards
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • 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
Place keywords Global Change Master Directory (GCMD) Location Keywords
  • Continent > North America > United States Of America
Stratum keywords Global Change Master Directory (GCMD) Location Keywords
  • Vertical Location > Land Surface
Use Constraints
  • Cite this dataset when used as a source.
  • Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
Access Constraints
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, 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.
Fees
  • In most cases, electronic downloads of the data are free, however fees may apply for data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: dataset
Lineage Statement RSI values are a function of the area affected by the snowstorm, the amount of snow, and the number of people living in the path of the storm. For a full description of how the Index was calculated, please view the documentation.
Processing Steps
  • For more information on the creation of this data, please view the documentation associated with the data.
Source Datasets
  • Snowstorm Database
    • Snowstorm Database
      Landing page for the Snowstorm Database, including links and other information.
    • Description of Source: Source dataset
    • Temporal extent used: 1900-01-01 to Present
  • U.S. Counties (Generalized) [from Census 2000]
  • U.S. Counties (Generalized) [from Census 2010]
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Acquisition Information (collection)
Instrument
  • SNOW MEASURING ROD
Platform
  • METEOROLOGICAL STATIONS
Last Modified: 2018-11-05
For questions about the information on this page, please email: ncei.orders@noaa.gov