“Near Miss” Events in the Urban Corridor

Abstract

The review and analyses of 30 snowstorms in the previous two chapters indicate that these storms are relatively rare events. Although the East Coast is the site of intense cyclogenesis during the winter months, cold air must be present, entrenched, or reinforced during the storm in order for precipitation to fall as snow rather than rain in the Northeast urban corridor. Furthermore, precipitation must persist for periods of 12 h or greater to allow snowfall amounts to reach 10 in. (25 cm) or greater. In many coastal storms, precipitation is more than likely to fall as rain or mixed precipitation rather than snow, especially south of New York City toward Washington, D.C. Even during those events in which cold surface air is sufficient for frozen precipitation, it is rare that precipitation will fall completely as snow, and will often fall as a combination of snow, ice pellets, freezing rain, and rain in the urban areas.