An Alberta Clipper system moved across the northern Great Lakes on the 29th bringing a light general snowfall across the area.  A strong coastal low then developed on the night of the 29th just off the New England coast. Colder air wrapping into the Great Lakes in the wake of this coastal low allowed lake effect snow to develop east of the lakes on westerly flow during the evening.  Lake effect snow focused on the western Southern Tier and southern Erie and Wyoming counties off Lake Erie, and the southern portion of the Tug Hill Plateau and Oswego County off Lake Ontario through the overnight hours.  Snowfall rates reached 2 inches per hour at times as the bands intensified overnight.  The Lake Ontario band produced several reports of thunder and lightning across Oswego County from mid evening on the 29th to the early morning hours on the 30th. On the 30th the wind veered more to the west-northwest, focusing the lake effect snow across the western Southern Tier off Lake Erie, and across Oswego, northern Cayuga, and northeast Wayne counties off Lake Ontario.  High pressure building into the Ohio Valley later on the 30th forced the Lake Erie lake effect snow to steadily weaken on the 30th.  Off Lake Ontario, a band of snow remained better organized into the night of the 30th and early morning of the 31st, focusing on areas right along the lakeshore near Oswego before weakening and drifting offshore by late morning.
Off Lake Erie, specific snowfall reports included: 18 inches at Randolph, Perrysburg, Springville and West Valley, 17 inches at West Almond, 15 inches at Angelica, South Dayton and Franklinville, 14 inches at Olean, Ellington and Kill Buck, 13 inches at Alfred, Colden, New Albion and Kennedy, 12 inches at Alfred Station, Sardinia, Busti, Rushford, Little Valley, Cattaraugus and Great Valley, 11 inches at Allegany, Sinclairville, Glenwood, Falconer and Frewsburg, 10 inches at Jamestown, Warsaw and Niobe, 8 inches at Wellsville, and 7 inches at Cuba and Colden.
Off Lake Ontario, specific snowfall reports included: 15 inches at Oswego, 14 inches at Minetto and Fulton, 13 inches at Palermo, 10 inches at Highmarket, Osceola, and Constableville, 8 inches at Glenfield and Bennetts Bridge, and 7 inches at Lowville and Pulaski.

Lake-Effect Snow in OSWEGO, NEW YORK
From 29-DEC-16 17:00:00 to 31-DEC-16 03:00:00 (EST-5)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Lake-Effect Snow in LEWIS, NEW YORK
From 29-DEC-16 19:00:00 to 30-DEC-16 12:00:00 (EST-5)
Property damage: 20.00K
Crop damage: 0.00K
Reported by: COOP Observer

Lake-Effect Snow in CHAUTAUQUA, NEW YORK
From 29-DEC-16 16:00:00 to 30-DEC-16 21:00:00 (EST-5)
Property damage: 15.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Lake-Effect Snow in CATTARAUGUS, NEW YORK
From 29-DEC-16 16:00:00 to 30-DEC-16 21:00:00 (EST-5)
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Lake-Effect Snow in SOUTHERN ERIE, NEW YORK
From 29-DEC-16 16:00:00 to 30-DEC-16 21:00:00 (EST-5)
Property damage: 15.00K
Crop damage: 0.00K
Reported by: COOP Observer

Lake-Effect Snow in WYOMING, NEW YORK
From 29-DEC-16 16:00:00 to 30-DEC-16 21:00:00 (EST-5)
Property damage: 12.00K
Crop damage: 0.00K
Reported by: COOP Observer

Lake-Effect Snow in ALLEGANY, NEW YORK
From 29-DEC-16 04:00:00 to 30-DEC-16 21:00:00 (EST-5)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: COOP Observer