Snowstorm catastrophes in the United States

Extremely damaging snowstorms, those causing more than $1 million in property losses across the US, were studied, and the spatial and temporal characteristics of the storm activity during 1949-2001 were defined. There were 155 catastrophic snowstorms and they caused insured losses of $21.6 billion (2001 dollars). The northeastern US had the nation's maximum storm occurrences (79 storms), greatest total losses ($7.3 billion), and highest storm intensity. Two-thirds of all US losses occurred in the Northeast, Southeast, and Central climate regions, and storm occurrences and losses were least in the western US. The incidence of storms peaked during the 1976-1985 period and exhibited no up or down trend during 1949-2001. However, losses had a significant upward time trend, as did storm sizes and intensity. New York and Pennsylvania had the greatest number of storms with fewest in Montana, Idaho, and Utah. Time distribution of losses in the northeastern and southeastern US were U-shaped with flat time trends for 1949-2001. Losses in the western regions and Deep South had distinct upward trends in losses, storm intensity, and storm size. More than 90 percent of all storm losses in the western US have occurred since 1980. These findings indicate that rapidly growing population and property at risk have been major factors in increasing losses as well as atmospheric changes leading to greater storm intensity and size.