A GIS-based assessment of lake-effect snow warnings in Upstate New York

Abstract

A GIS-based assessment of lake-effect snow warnings in Upstate New York. J. Operational Meteor., 2 (6), 5970, doi: http://dx.doi.org/10.15191/nwajom.2014.0206. ) also have been documented. Twenty-four-hour snowfall measurements taken by National Weather Service (NWS) observers during Lake Ontario LES events were collected. Utilizing a geographic information system, snowfall was interpolated from spotter reports with the kriging method. Then, the area of warning-criteria snowfall was compared to the area of the corresponding county-based LES warning for calculation of false alarm percentage. This warning performance evaluator identified the proportion of a county-based LES warning that received sub-warning-criteria snowfall. Percent of false alarm was calculated using temporally comparable snowfall reports and all available reports from each event. Corresponding author address:A total of 13 events from the 2009-2010 through 2011-2012 LES seasons were analyzed. The average percent of false alarm was approximately 90%. This suggests the NWS should consider smaller warning polygons. Limited-size warnings would enable meteorologists to provide greater specificity regarding the location of anticipated significant snowfall, while simultaneously reducing the number of people who are unnecessarily warned.