Authors: Zachary Suriano*, Department of Geography & Geology, University of Nebraska - Omaha, Daniel J Leathers, Department of Geography, University of Delaware, Dorothy K Hall, Earth System Science Interdisciplinary Center/University of Maryland, Allan Frei, Department of Geography, Hunter College, City University of New York
Topics: Climatology and Meteorology, Cryosphere, Physical Geography
Keywords: snowfall, synoptic classification, lake-effect, Northeast US
Session Type: Paper
Start / End Time: 1:10 PM / 2:50 PM
Room: Truman, Marriott, Mezzanine Level
Presentation File: No File Uploaded
Snowfall in the six basins of the Catskill/Delaware watershed in south-central New York State historically contributes roughly 20-30% of the water resources derived from the watershed for use in the New York City water supply. The watershed regularly experiences snowfall from three distinctive weather patterns: inland tracking mid-latitude cyclones, coastal mid-latitude cyclones, and lake-effect or Great Lakes enhanced storms. Using synoptic weather classification techniques, these distinct regional atmospheric patterns impacting the watershed are isolated and analyzed in conjunction with daily snowfall observations from 1960-2009 to allow the influence of each synoptic weather pattern on snowfall to be evaluated independently.
Results indicate that snowfall-producing events occur on average approximately 63 days per year, or once every four days during the October-May season, leading to an average of 213 cm year-1 of snowfall within the watershed. Snowfall from Great Lakes enhanced storms and inland tracking mid-latitude cyclones contributes nearly equally to seasonal totals, representing 38% and 39%, respectively. Coastal mid-latitude cyclones, while producing the highest amount of snowfall per event on average, contribute only 16% to the watershed average total snowfall. Predicted climatic change is expected to impact snowfall differently depending on the specific atmospheric pattern producing the snow. As such, quantifying the contribution of snowfall to the watershed by synoptic pattern can inform future water management and reservoir operation practices for the New York City Water Supply Management System.