Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
308 PM EST Mon Feb 07 2022

Valid 00Z Tue Feb 08 2022 - 00Z Fri Feb 11 2022

...New England...
Days 1-2...
Supported by an amplifying upper trough moving from the Great
Lakes-Ohio Valley into the Northeast, surface low pressure
developing along the Mid Atlantic coast this evening will
gradually intensify as it tracks east of New England on Tuesday. 
Strong ascent afforded in part by a coupled upper jet and
low-to-mid level frontogenesis is expected to help support a swath
of moderate to locally heavy precipitation developing northwest of
the low and centered across northern New England on Tuesday.  WPC
probabilities indicate that snowfall accumulations of 4 inches or
more remain most likely from the Presidential Range in northern
New Hampshire to northern Maine, with warm advection expected to
limit the threat for significant accumulations across areas
farther south.

...Great Lakes...
Days 2-3...
The next wave crosses Ontario Tuesday night with cold post-frontal
northwesterly flow bringing a threat for lake effect snows across
the western Great Lakes on Wednesday, before spreading east into
the eastern Great Lakes late Wednesday into Thursday.  WPC
probabilities continue to show the greatest threat for
accumulation of 4 inches or more centered across the Porcupine in
the U.P. of Michigan on Wednesday and then in the Tug Hill Region
of Upstate New York on Thursday.

...Black Hills...
Days 2-3...
A mid-level shortwave embedded within progressive northwest flow
along with left-exit region upper jet forcing is expected to
support snow spreading south through the northern High Plains late
Wednesday.  For most areas, accumulations are expected to be
light.  However, WPC probabilities indicate the potential for
locally heavier totals -- 4 inches or more -- across the Black
Hills, where upslope flow may bolster amounts along the northern
slopes.

The probability of significant icing is less than 10 percent.

Pereira