List of Regional Snowfall Index Category 5 winter storms

Snowfall map of the Great Blizzard of 1978, the highest-ranking storm on the Regional Snowfall Index, outlining the six regions assessed with the scale.

The Regional Snowfall Index (RSI) is a system used by NOAA to assess the societal impact of winter storms in the United States. The system is a replacement for the Northeast Snowfall Impact Scale (NESIS) system. Since its initiation, the NCDC has retroactively assigned RSI values to over 500 historical storms since 1900.

Storms are ranked from category zero ("Nuisance") to five ("Extreme") on the scale. The impact of the storms is assessed in six different regions of the United States: Northeast, Northern Rockies & Plains, Ohio Valley, South, Southeast, and Upper Midwest. A category five Extreme ranking is indicated by a numerical score of 18 or higher on the scale.

Out of the over 500 historical storms assessed since 1900, only 26 storms have been given a category five ranking. The highest ranking storm on the list is the Great Blizzard of 1978, which scored a value of 39.07. The most recent storm to receive a category five ranking is the January 2016 United States blizzard, which scored a value of 20.14. The following list orders the storms chronologically.

List of Category 5 events

Year Date Max. RSI Region Ref(s)
1920 April 14–18 20.84 Northern Rockies and Plains
1921 February 17–21 31.89 South
1922 January 25–29 18.53 Southeast
1927 February 26 – March 2 24.42 Southeast
1927 April 4–10 34.20 Northern Rockies and Plains
1929 December 18–23 21.13 South
1940 January 20–23 18.14 Southeast
1943 January 18–25 21.14 Northern Rockies and Plains
1950 November 11–21 34.69 Ohio Valley
1966 February 27 – March 5 20.38 Northern Rockies and Plains
1967 January 24–28 18.13 Ohio Valley
1969 February 21–27 34.03 Northeast
1971 February 18–23 19.36 South
1978 January 22–27 39.07 Upper Midwest, Ohio Valley
1978 February 5–7 18.42 Northeast
1984 April 24–27 25.95 Northern Rockies and Plains
1985 February 6–14 27.06 Upper Midwest
1985 November 27 – December 1 22.19 Upper Midwest
1988 January 4–8 22.64 South
1991 October 30 – November 3 30.18 Upper Midwest
1993 March 11–14 24.63 Northeast, Ohio Valley, Southeast
1993 November 20–28 22.00 Northern Rockies and Plains
1996 January 5–8 26.37 Northeast, Southeast
2009 December 21–28 19.62 Northern Rockies and Plains
2011 January 31 – February 2 21.99 Ohio Valley
2016 January 19 – January 29 20.14 Northeast

Listed by month

See also


This page was last updated at 2023-10-05 07:23 UTC. Update now. View original page.

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