An Investigation of New York State Finger Lakes Snow Band Events

Much of the current knowledge regarding lake-effect snow storms has been developed through investigations of systems associated with large water bodies, such as the Great Lakes and the Great Salt Lake. Lake-effect snowfalls and mesoscale circulations associated with small lakes, with fetches less than 40 km, have received less attention. While the spatial scale of these systems is smaller than those that develop over larger lakes, significant snowfall totals have been observed with these mesoscale lake-effect events. The Finger Lakes region of New York State (NYS) harbors a collection of small lakes with differing sizes which produce lake-effect snow systems. This observational study provides a unique examination of the frequency, spatial distribution, intensity, and conditions favorable for lake-effect systems associated with these small lakes.

Previous investigations of NYS Finger Lakes snow events have used mesoscale models to examine a limited number of cases. The current study used Binghamton, NY WSR-88D radar data to examine lake-effect events for the winters (October – March) of 1995 through 2004. Events were separated into two classifications; lake-effect and lake enhanced. Lake-effect events developed over and downwind of a lake and were not associated with larger-scale systems. Lake-enhanced events occurred when previously existing precipitation systems were noticeably enhanced in the vicinity of the lakes.

Several aspects of the research investigation of NYS Finger Lakes snow band events will be presented. The time period when early season lake-effect rain events change to snow events was evaluated and compared to previous research completed for Lakes Erie and Ontario. Lake-effect events were found to occur throughout the winter in the Finger Lakes region with the greatest frequency in January. Snow bands developing during lake-effect events were typically located to the south and southeast of the north-south elongated Finger Lakes. Two types of lake-enhanced events were discovered. The first type occurred in association with synoptic-scale systems. The second type occurred in association with pre-existing lake-effect snow bands originating from Lake Ontario. Several notable lake-effect and lake-enhanced events will be presented.