Cold front blasts across region late Sunday afternoon into early
Sunday evening. Cold air advection will quickly switch rain to snow
by Sunday evening first over the hills of western NY into the higher
terrain of the Southern Tier, but eventually all areas (even lower
elevations) will see snow by late evening into the early overnight.
Widespread precip will end in the evening, but the deep cold trough
with deeper moisture and sharply increasing over-water instability
leading to lake equilibrium levels/inversion heights rising toward
15kft will result in *at least* moderate intensity lake effect
snowfall for areas favored by northwest winds Sunday evening
through late Sunday night. Will be a multiband regime, but there
continues to be hints of upstream connections off Lake Huron
and Georgian Bay which will boost intensity than what would
typically occur in multiband setup. Several inches of snow is
looking more likely Sunday night over western Southern Tier and
also vcnty of the Tug Hill east of Lake Ontario. Another plus
is, at least right now, forecast soundings show uniform winds
for the depth of the lake convective layer, thus minimal shear
to disrupt the lake effect. Strong winds in that layer could
displace the snow showers farther inland as well and may even
lead to a bit of blowing snow as temps fall into the 20s
overnight. Will continue to mention this potential snow in the
HWO. Adding to the wintry feel will be wind chill values to
start the day Monday in the teens and lower 20s. Brrr.
Snow showers will be around on Monday, but as upper level trough
moves east of the region, limited deeper moisture and some
subsidence/drying will likely diminish intensity compared to Sunday
night. Does appear lake effect will flare up again late Monday into
Monday night, this time mostly over Tug Hill closer to departing
trough and colder air.