On the frequency of lake-effect snowfall in the Catskill Mountains

ABSTRACTMeltwater from snowthat falls in the Catskill/Delaware watershed in the Catskill Mountains in south-central New York contributes to reservoirs that supply drinking water to approximately nine million people in and near New York City (NYC). Using the Interactive Multisensor Snowand Ice Mapping System (IMS) 4-km snowmaps from the National Oceanic and Atmospheric Administration’s National Ice Center, we identified and tracked 28 lake-effect (LE) storms that deposited snowin the Catskills (2004–2017). These storms, which generally originated from Lake Ontario, but sometimes from Lake Erie, represent an underestimate of the number of LE storms that contribute snowfall to the Catskills snowpackbecause snowstorms are not visible on IMS maps when they travel over already- snow-covered terrain. Using satellite, meteorological (including NEXRADand National Weather Service Cooperative Observer Program), and reanalysis data, we identified conditions that contributed to the LE snowstorms and mapped snow-c...