A comparison of two exceptional snowstorms during the early 20th century

Two East-Coast snowstorms of the early twentieth century, which generated massive accumulations over portions of the Atlantic coastal plain, are described. The 'Christmas Storm' of December 25-26, 1909 produced snowfalls of greater than 25 cm over most of the Northeast Corridor from Maryland to southern New England, while the 'Knickerbocker Storm' of January 27-29, 1922 produced a total of 71 cm at Washington, DC. The storms are examined by constructing surface-weather analyses based on original data; surface observations for the continental United States at 0100 and 1300 UTC are obtained from the National Climatic Data Center (NCDC), ship reports from American vessels are taken from the NCDC archives, and the 1300 UTC data is supplemented by Canadian observations and European ship reports. In spite of the vast differences in the evolutions of the storms, it is found that both produced similarly massive snowfalls, therefore, it is concluded that a wide range of synoptic conditions can give rise to major snowstorms along the East Coast.