Another strong mid level shortwave and associated surface low will
reach the eastern Great Lakes very late Tuesday afternoon and
evening. While model guidance is in good agreement with the large
scale features, there are some differences in the finer details as
to where the band of most persistent precipitation will develop with
this system. The initial area of precipitation will be in the form
of rain late Tuesday afternoon and evening. Cold advection will
increase Tuesday night, allowing the rain to change to snow later
Tuesday night. Precipitation will be mainly snow by Wednesday
morning, with the possible exception of the immediate lakeshores.
Some minor accumulations are expected by daybreak Wednesday across
higher terrain.
Wednesday and Wednesday night a surface low will rapidly deepen over
the Gulf of Maine before moving into the Canadian Maritimes. A deep
mid level trough will carve out across the Great Lakes and New
England, with several mid level shortwaves moving through the
longwave trough. An extended period of moist northwest flow will
setup across the eastern Great Lakes, with lake induced equilibrium
levels rising to over 8K feet with time. This will all support
widespread snow showers and embedded areas of steadier light snow
Wednesday and Wednesday night. The combination of lake enhancement
and northwest upslope flow will bring accumulating snows to the
higher terrain of the western Southern Tier, Tug Hill, and western
foothills of the Adirondacks. This may require winter headlines as
the details become more apparent and confidence increases on the
timing and placement of heavier snow amounts. Even across the lower
elevations of the lake plains expect some modest accumulations
during this time period. It will also be quite windy Wednesday and
Wednesday night with some blowing and drifting snow in areas which
receive accumulation.