List of Regional Snowfall Index Category 4 winter storms

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Snowfall map of the February 1973 United States blizzard, a Category 4 winter storm, outlining the thresholds for Regional Snowfall Index in the Southeast and showing the different regions assessed using the scale February 1973 United States blizzard.jpg
Snowfall map of the February 1973 United States blizzard, a Category 4 winter storm, outlining the thresholds for Regional Snowfall Index in the Southeast and showing the different regions assessed using the scale

The Regional Snowfall Index (RSI) is a system used by NOAA to assess the societal impacts of winter storms in the United States. The scale is a replacement for the Northeast Snowfall Impact Scale (NESIS) system, which was used for winter storms just in the Northeastern United States; Regional Snowfall Index assesses winter storm impacts in the six easternmost regions of the United States instead of just the Northeast. Since its initiation, the NCDC has assigned RSI values to nearly 600 winter storms since 1900.

Contents

Storms are ranked from Category 0 "Nuisance" to Category 5 "Extreme" on the scale. A Category 4 winter storm on the RSI scale is classified as "Crippling". The impact of the storms is assessed in six different regions of the United States: the Northeast, Northern Rockies and Plains, Ohio Valley, South, Southeast, and Upper Midwest. [1] A Category 4 "Crippling" ranking is indicated by a numerical score between 10 and 18 on the scale.

Out of the nearly 600 historical winter storms assessed since 1900, only 74 storms have been given a Category 4 or above ranking, 48 of which were Category 4 storms. The highest ranking Category 4 winter storm is the March 2–8, 1915 United States blizzard, which had an RSI of 17.67. The most recent storm to receive a Category 4 ranking is the December 2022 North American winter storm, which scored an RSI value of 11.49. The following list orders the Category 4 storms chronologically. [1] [2] [3]

List of Category 4 events

This list includes all winter storms which had a maximum RSI value in the Category 4 range. Storms that ranked as a Category 4 in some regions but ranked as a Category 5 in one or more other regions are not included in this list. [4] [2]

YearDateMax. RSIRegion
1900February 26 March 315.65Northeast, South
1902February 131910.16Southeast
1902March 3612.19Northeast, South
1910February 161811.34Ohio Valley
1913November 71116.09Ohio Valley
1915March 2817.67Northern Rockies and Plains, South
1918December 212610.61South
1929December 162110.62Upper Midwest
1930December 131813.97Southeast
1933April 182212.69Northern Rockies and Plains
1936February 6811.26Southeast
1947January 273110.18Upper Midwest
1947February 27 March 410.63Northeast
1949January 1615.79Northern Rockies and Plains
1951March 91712.97Upper Midwest
1955April 3616.93Northern Rockies and Plains
1956January 31 February 613.78South
1962February 28 March 711.79Southeast
1962March 5912.66Southeast
1966 January 2731 12.28Northeast
1969December 252910.14Northeast
1971February 26 March 610.18Northeast
1973February 91112.52Southeast
1978December 28, 1978 January 3, 197910.08Upper Midwest
1979 January 1314 14.42Ohio Valley
1979February 172015.01Southeast
1979November 172210.81Northern Rockies and Plains
1980February 51010.55South
1980February 28 March 315.14Southeast
1983February 101314.78Southeast
1985March 1515.18Upper Midwest, Northern Rockies and Plains
1987January 212413.16Southeast
1987April 2611.21Ohio Valley
1999 January 24 15.30Upper Midwest, Ohio Valley
2003 February 1419 14.67Northeast
2004 December 2124 11.31Ohio Valley
2005 January 2023 10.34Northeast
2006March 192214.22Northern Rockies and Plains
2009March 273014.95South
2009 December 1620 15.71Southeast
2010 February 56 10.15Southeast
2010February 81312.75South
2010February 101310.07South
2010 February 2527 15.85Northeast
2011February 91111.80South
2014 February 1124 10.66Southeast
2017 March 1115 10.66Northeast
2018 April 1315 15.7Upper Midwest
2022December 13-2010.35Upper Midwest
2022 December 2126 11.49Upper Midwest

Listed by month

See also

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Category 4 or Category IV may refer to:

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References

  1. 1 2 "Regional Snowfall Index (RSI)". NOAA: National Centers for Environmental Information. Retrieved December 26, 2020.
  2. 1 2 "Regional Snowfall Index and Societal Impacts" . Retrieved December 26, 2020.
  3. "NOAA Product Highlight: Regional Snowfall Index". Archived from the original on November 29, 2014. Retrieved December 26, 2020.
  4. 1 2 Squires, Michael; Lawrinmore, Jay; Heim, Richard; Robinson, David; Gerbush, Mathieu; Estilow, Thomas. "The Regional Snowfall Index" (PDF). American Meteorological Society. Retrieved December 26, 2020.