Summary of the Physical and Dynamical Processes that Influence Northeast Snowstorms

Abstract

Twenty severe snowstorms that affected the northeastern coast of the United States between 1955 and 1985, have been selected for study based on their extensive distribution of heavy snowfall (>25 cm) across one of the most heavily populated and industrialized regions of the world, including the metropolitan areas of New York, Washington, Boston, Philadelphia, and Baltimore. Analyses of the surface and upperlevel fields of pressure, geopotential height, wind, and temperature, plus other selected elements described in the preceding two chapters, provide a framework for understanding the dynamical and thermodynamical processes that contribute to heavy snowfall in the northeastern United States. These analyses point out the important role of cyclogenesis, which was observed to some degree in each of the 20 snowstorms. Surface cyclogenesis involved either a primary low-pressure center or a secondary development along the Southeast or Middle Atlantic coast that tracked northeastward approximately 100 to 300 km offshore.