A persistent upper level trough over eastern Canada kept a cold westerly flow over the Great Lakes. The event started Sunday afternoon (December 15th) to the east of Lake Erie during the afternoon hours. The snow fell at up to three inches per hour with near zero visibility in a 15-mile wide band from Hamburg and Orchard Park to East Aurora and Wales. Traffic cameras showed snow covered roads and near whiteout conditions with several reports of cars sliding off the road. The band extended inland across southern Genesee and northern Wyoming counties to northern Livingston County. Snow totals of up to a foot were reported in 3 hours between 4 and 7 P.M. across southern Erie and Genesee Counties along with numerous reports of thunder snow in the vicinity of Orchard Park.  The band shifted back south under westerly winds during the evening and continued into the night. Snow totals of a bit over a foot accumulated across northern Chautauqua and Cattaraugus and southern Wyoming Counties. Specific reports included: 14 inches at West Valley, 13 inches at Perrysburg; 12 inches at Orchard Park and 11 inches at Varysburg and East Aurora.
Off Lake Ontario, the lake effect snow band formed Sunday evening with a long-axis parallel lake band focused directly east of the Lake across southern Jefferson and northern Oswego counties. The band maintained this position for about four hours before the band shifted south along the southern lake shore.  Snowfall rates of three to four inches per hour were observed by researchers studying lake effect snow in northern Oswego County which produced snow accumulations of 8 to 14 inches east of the lake before the band shifted south. During the early morning hours of Monday December 16th thunder snow was also recorded in the Lake Ontario snow band.  Through the remainder of the morning hours up to and past daybreak a very narrow and shallow lake band of less than five miles in wide hugged the southern Lake Ontario shoreline from Olcott in Niagara County to north of Rochester to the towns of Port Bay and Red Creek in far northeastern Wayne County. Specific snowfall reports included: 23 inches at Port Bay, 18 inches at Red Creek and 13 inches at Fair Haven and Lacona.

Lake-Effect Snow in CHAUTAUQUA, NEW YORK
From 15-DEC-13 17:00:00 to 15-DEC-13 23:59:00 (EST-5)
Property damage: 8.00K
Crop damage: 0.00K
Reported by: COOP Observer

Lake-Effect Snow in CATTARAUGUS, NEW YORK
From 15-DEC-13 17:00:00 to 15-DEC-13 23:59:00 (EST-5)
Property damage: 12.00K
Crop damage: 0.00K
Reported by: COOP Observer

Lake-Effect Snow in SOUTHERN ERIE, NEW YORK
From 15-DEC-13 17:00:00 to 15-DEC-13 21:00:00 (EST-5)
Property damage: 11.00K
Crop damage: 0.00K
Reported by: COOP Observer

Lake-Effect Snow in GENESEE, NEW YORK
From 15-DEC-13 17:00:00 to 15-DEC-13 22:00:00 (EST-5)
Property damage: 7.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Lake-Effect Snow in WYOMING, NEW YORK
From 15-DEC-13 17:00:00 to 15-DEC-13 23:59:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Lake-Effect Snow in LEWIS, NEW YORK
From 15-DEC-13 22:30:00 to 16-DEC-13 03:00:00 (EST-5)
Property damage: 13.00K
Crop damage: 0.00K
Reported by: COOP Observer

Lake-Effect Snow in NORTHERN CAYUGA, NEW YORK
From 15-DEC-13 23:00:00 to 16-DEC-13 06:00:00 (EST-5)
Property damage: 15.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Lake-Effect Snow in WAYNE, NEW YORK
From 15-DEC-13 23:00:00 to 16-DEC-13 06:00:00 (EST-5)
Property damage: 23.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Lake-Effect Snow in OSWEGO, NEW YORK
From 15-DEC-13 20:00:00 to 16-DEC-13 03:00:00 (EST-5)
Property damage: 8.00K
Crop damage: 0.00K
Reported by: Trained Spotter