87th AMS Annual Meeting

Saturday, 13 January 2007
New York State Finger Lakes winter lake-effect events: event characteristics
Natasha Hodas, Cornell University, Ithaca, NY; and R. Sobash and N. Laird
Much of the current knowledge regarding lake-effect snow storms is associated with large water bodies, such as the Great Lakes and the Great Salt Lake. Snowfall events attributed to small lakes (fetch < 100km) have received less attention, although significant snowfall totals have been documented with these systems. This study uses data from the eleven winters (October March) of 1995 through 2006 to examine lake-effect systems in the Finger Lake region of New York State (NYS) and the atmospheric environments favorable for their development. WSR-88D radar data from Binghamton, NY was used to identify 125 lake-effect events which contained quasi-stationary precipitation bands aligned with a major-axis of one or more of the Finger Lakes. The lake-effect events were classified into three main categories: Finger Lakes (36), Lake Ontario-enhanced (57), and synoptic-enhanced (15). In addition, 17 cases occurred which transitioned from one main category to another during the lake-effect systems evolution.

The frequency, duration, timing, and environmental conditions during the 125 events were examined. Lake-effect events were found to (a) have an average duration of 9.4 hours, with 75% of events lasting less than 14 hours, and (b) occur throughout the 6-month period. The largest frequency of events typically occurred in December, with an average of 3 events per year. October was shown to be the least active month averaging 1 event per year, with several of the identified events developing as lake-effect rain systems. Cayuga Lake, the second largest of the Finger Lakes, has the largest frequency of events during the winter. Analyses of lake-effect event onset and dissipation showed events predominantly began between 00 - 12 UTC in association with a trough or frontal passage and dissipated in the early evening as the linear precipitation bands transitioned into a field of widespread cellular convection. A comparison of NYS Finger Lakes events with the characteristics (e.g., timing and frequency) of Great Lakes lake-effect events will be presented.

Supplementary URL: