Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
350 AM EST Mon Nov 10 2025

Valid 12Z Mon Nov 10 2025 - 12Z Thu Nov 13 2025

...Great Lakes through Interior Northeast and Appalachians...
Days 1-2...

Deepening upper-low over northern Indiana early this morning swings
southeast over the Ohio Valley today before crossing the Mid-
Atlantic tonight before lifting over New England Tuesday. Strong
and cold northerly flow in the wake of the low persists over Lakes
Superior and Michigan today with northwesterly flow over the
eastern Great Lakes. The cold airmass will have 850mb temps of -10
to -12Z (near the DGZ) which compared to lake temps around +10C
will
make for efficient LES banding and a decent, but short lived lake
effect event.

Furthermore, northwesterly flow into the central Appalachians will
make for a decent upslope snow event in West Virginia. Day 1 snow
probs for >6" after 12Z are over 50% in the western shore of MI
from Manistee to Muskegon and south from Holland into north-central
Indiana. Of note, recent HRRRs have maintained the heavy snow
banding in Chicago into the mid-morning hours (longer than
previously forecast). These higher snow probs are also over
northwest PA and the Chautauqua Ridge area of far western New York
and along the southern shore of Lake Ontario as well as the
Allegheny Highlands of WV. As flow becomes more westerly tonight,
the focus over Lake Ontario shifts farther east and includes the
southern Tug Hill to Syracuse where Day 1.5 probs for >6" are
around 40%.

Warm air advection on westerly flow over spreads the eastern Great
Lakes Tuesday night with some higher elevation LES continuing into
Wednesday.


The probability of significant icing is less than 10 percent.


Jackson