Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
355 PM EST Mon Jan 19 2026

Valid 00Z Tue Jan 20 2026 - 00Z Fri Jan 23 2026


...Great Lakes/Upper Midwest...
Days 1-3...

A highly negative AO teleconnection will keep the large Hudson Bay
vortex in place while embedded shortwave troughs revolving around
the Hudson Bay vortex continue to trigger LES bands over the
typical snow belts. The Great Lakes are remain ice free away from
the narrower bays and coast lines. Sufficiently steep lapse rates
persist due to 850mb temperatures of -20C to -25C racing over
surface water temperatures between +2C to +6C.

For Lakes Erie/Ontario, SWly flow veers Wly today and tonight with
ongoing single-band LES shifting south of Buffalo and onto the Tug
Hill Plateau. Day 1 PWPF for >6" are 70-90% in these zones.

A brief lull occurs Tuesday evening in the western Lakes and
eventually eastern Lakes by Wednesday morning under brief ridging
until the next shortwave/a clipper system shifts east through the
region Tuesday night through Wednesday. A surface low lifts from
Iowa across the L.P. through that time with synoptic snow bands
across northern Iowa and southern Wisconsin where Day 2 snow probs
for >4" are 10-20%. Brief LES can be expected Wednesday into
Wednesday night where Day 2.5-3 PWPF for >4" are 40-70% in the
western U.P., the length of the western L.P. shore, and east of
Lakes Erie and Ontario.

Yet another clipper is quick on the heels on a similar path to the
previous with snow bands likely over northern Iowa, southern
Wisconsin and souther Michigan again Wednesday night through
Thursday. In total through Thursday, snowfall amounts are expected
to add up to at least 1 to 2 feet downwind of Lake Erie and Lake
Ontario, with higher chances (60-80%) for over 2 feet across the
Tug Hill of NY.


The probability of significant icing is less than 10 percent.


Snell/Jackson