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
Dataset Information
Online Access
Distribution Formats
  • CSV
  • fixed-length ASCII text
  • ArcGIS
DistributorDOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
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
General Documentation
Associated Resources
Publisher
  • 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
Originator
  • DOC/NOAA/NESDIS/NCDC > National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce
Date(s)
  • 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 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.
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:
Theme 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
  • 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
  • Continent > North America > United States Of America
Stratum keywords
  • Vertical Location > Land Surface
Use 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.
Fees
  • Electronic downloads of the data are free, however fees may apply for data certifications and data distribution on physical media.
  • 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 StatementRSI 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.
  • 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.
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]

Last Modified: 2016-08-19

For questions about the information on this page, please email: ncdc.metadata@noaa.gov