Weak ridging aloft across the Lower Great Lakes will give way to an
impending upstream shortwave that is in the process of diving
southeast from Lake Superior. Ahead of this system...winds will back
to a WSW`erly flow which will nudge lake snows back out over the
open waters of Lake Ontario and then direct lake effect snows into
Oswego county overnight. As the shortwave and corresponding surface
reflection nears the region lake effect snows will then become
reinvigorated as synoptic moisture ramps up and equilibrium levels
climb over 12K feet. This will be the much need juice to provide an
additional 3-6" inches across Oswego County overnight. This feature
will also produce some light snow showers with some minor
accumulations expected across the region overnight.
As the surface low crosses the lakes during the wee hours Thursday
morning a wind shift will occur to NW`erly in its wake. This will
send all remain lake snows southeast of Lake Ontario. Expect
additional accumulation of 1-3" in the most persistent snows
southeast of lake Ontario Thursday. All remaining synoptic snows
will quickly diminish with its departure by mid morning. Behind this
system high pressure will begin to take hold across the lower lake
and synoptic moisture will get stripping away. Additionally,
equilibrium levels will lower and lake snows will continue to weaken
and then diminish. Otherwise, outside of the lake snows it will
continue to be cold with highs expected in the upper teens to lower
20s areawide which is well below normal. Where should we be for this
time of year, upper 30s near 40F.