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A Northeast snowfall impact scale is presented to convey a measure of the impact of heavy snowfall in the Northeast urban corridor, a region that extends from southern Virginia to New England.
Meteorological impact scales have been devised to relate wind speeds associated with tornadoes (Fujita 1971) and hurricanes (Saffir 1977) to structural damage. These scales provide benchmarks with which to assess the destructive potential of individual storms and to communicate that potential to the public. In the case of tornadoes, that assessment is typically made following the storm's occurrence. In the case of hurricanes, wind measurements are made during the storm's lifetime, allowing an assessment during the evolution of the storm. Thus, the scales can help in decision-making processes involved in either evacuation (in the case of hurricanes), evaluating building codes, or performing other actions necessary to save lives and mitigate potential property loss, as well as providing a historical perspective.
Snowstorms are complex phenomena whose impact can be affected by a great many factors, including a region's climatological susceptibility to snowstorms, snowfall amounts, snowfall rates, wind speeds, temperatures, visibility, storm duration, topography, and occurrence during the course of the day, weekday versus weekend, and time of season. With such complexity, quantifying the impact of snowstorms with a scale that can be easily conveyed to the general public is difficult. Until recently, relatively little has been done to classify major winter storms.
Hart and Grumm (2001) use a method based on a normalized departure from climatology of tropospheric values of height, temperature, wind, and moisture to rank extratropical and tropical weather events, including Northeast snowstorms, computed from the "reanalysis dataset" over a 53-yr period (Kalnay et al. 1996). Using the Hart and Grumm methodology, the highest-ranked storm (most climatologically anomalous) was the January 1956 "Great Atlantic Low" (Ludlum 1956; also see chapter 11 of Kocin and Uccellini 2004b) while the March 1993 Superstorm ranked third in the 53-yr study period.
Zielinski (2002) also utilizes a synoptic climatology, but focuses on major East Coast snowstorms during a 30-yr period, 1955-85 (Kocin and Uccellini 1990) and several historic and recent storms to devise a scale for winter cyclones. As is the case for Hart and Grumm, Zielinski's scale relies mostly on the meteorological attributes of...