A SYNOPTIC CLIMATOLOGY FOR HEAVY SNOWFALL EVENTS SPANNING THE EAST COAST MEGALOPOLIS: INSIGHTS FROM NORTHEAST SNOWSTORMS

摘要

Analysis of the historical major snowfall events for the East Coast Megalopolis (Washington D.C. through Boston) reveals an interesting pattern. While storms bringing 10 inches or more to parts of the region have involved numerous combinations of features, those bringing that much snowfall to all of the major cities in the region were remarkably similar. This paper discusses those similarities with a view towards providing forecasters and emergency managers with insights into which storm types are capable of crippling the entire East Coast Megalopolis. Five of the six historical storms that have brought 10 inches of snow to Washington D.C., Baltimore, Philadelphia, New York City, and Boston have followed similar tracks: along the Gulf Coast and thenup the Atlantic Seaboard. The sixth storm exhibited coastal redevelopment and then followed a similar track. Three of these storms remained close to the coast while three angled farther offshore after passing Cape Hatteras, North Carolina. All six cyclones caused the steady progression of an onshore 850 mb jet northeastward across the entire Megalopolis, and five of the six storms interacted with an anticyclone of the same type.