Stacked low over the Upper Mississippi valley Friday morning will
move to Illinois/Indiana by Friday evening, while its associated
surface occlusion will advance from the Upper Ohio Valley to
the southwest corner of New York state. Warmer air ahead of the
system will allow the nearly all the precipitation that arrives
by afternoon into western New York ahead of the occlusion to
fall as rain. Temperatures will climb well into the 40s across
the lake plains.
The main surface low will move into the Great Lakes and weaken
Friday night as a secondary wave develops along the occlusion
near New Jersey and then takes over as the primary low as it
moves into New England Saturday. Colder air will wrap into the
area Friday night with a change over to wet snow, but snow
accumulations through Saturday will be limited to an inch or
two for most, with better accumulations confined to the higher
terrain east of Lake Ontario where significant accumulation is
possible.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
Maturing low pressure centered over central New England Saturday
night will travel northeast across Maine and eventually enter New
Brunswick by Sunday evening. In its wake, west-northwesterly flow
will support a few to several inches of accumulating snow east of
both lakes.
Diving into the details, temperatures at 850mb throughout this
period will average around -8C throughout the majority of the
period. While this isn`t cold enough for pure lake effect, the west-
northwest flow along with wrap around moisture from the departing
low will support lake enhancement off of both lakes Erie and
Ontario. Of the two lakes, snows off of Lake Ontario, especially
locations in close proximity of the Tug Hill, will have the better
chances for accumulating snows due to possibilities of lake to lake
connections. Though not as favorable, the snows off of Lake Erie
look best to accumulate across the Chautauqua Ridge.
Chances for lake snows will continue throughout the day on Sunday
with a couple of inches of additional snowfall possible.