December 27-30 Clipper and Lake Effect Snow Potential...

Discussion...

Synoptic Snowfall:
This is likely going to be a quick and hard hitting 2-4 incher for a widespread area, blossoming into much heavier totals once into northern New England as the low strengthens. Once east of the apps, downsloping should make for little or no accumulations from both the clipper and lake effect, especially for the Susquehanna Valley of PA and points east and south. Meanwhile, while this system exits New England, the lake effect is going to kick up in earnest and add additional significant snows to the folks in the traditional favored areas. Once east of the apps, downsloping should make for little or no accumulations from both the clipper and lake effect, especially for the Susquehanna Valley of PA and points east and south.

..GLUNT.. 12/27/2009

Lake Effect Snow:
Off Lake Erie... snow bands should begin forming by Monday morning. Initially, flow will be more westerly which will produce moderate snows east of the lake into favored areas of Southern Erie, Wyoming, and northern Chautauqua and Cattaraugus counties. Total lake effect snowfall will likely range from 4-8” before winds begin shifting to the northwest and heaviest snows begin to setup from southern Chautauqua county NY to Ashtabula county OH by late Monday Night. Between then and Tuesday night, flow should remain fairly steady resulting in significant accumulations downwind, especially if any upstream connections become sustained for a long period of time. For this reason, we have also extended significant accumulations further inland to the highlands of interior western PA. By the time the snow winds down, total accumulations from Sunday Night thru Wednesday Morning will likely range from 12-24”where the most persistent bands develop.

Off Lake Ontario... snow bands should begin developing by Monday Evening. Initially the flow will be more westerly, resulting in moderate snows east of the lake over portions of Jefferson, Lewis, Herkimer, and Oneida counties. Total Lake Effect snowfall will likely range from 4-8” before winds begin shifting to the northwest and heaviest snows begin to setup over portions of Oswego, Oneida, Madison, Onondaga, Wayne, and Cayuga Counties by Tuesday Morning. Between then and Wednesday Afternoon, flow will remain fairly steady resulting in significant accumulations downwind. At the same time, multi-bands off Cayuga and Seneca Lakes should be impacting a large portion of South Central NY and far Northeastern Pennsylvania. By time the snow tapers off Wednesday Afternoon, Total accumulations of 6-10”are likely across portions of Tompkins, Tioga, and Broome Counties in areas where the most persistent bands occur. Further north, greatest amounts should be focused over portions of Madison, Onondaga, Oswego, Oneida, Wayne, and Cayuga Counties, where localized total accumulations will likely range from 12-24” in areas where the most persistent bands occur, with lesser amounts of 6-12”likely across portions of Chenango, Cortland, and Seneca counties.

It should also be noted that considerable blowing and drifting of the snow is likely, especially Tuesday into Wednesday.

..EGAN.. 12/27/2009