Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
335 PM EST Fri Nov 15 2019

Valid 00Z Sat Nov 16 2019 - 00Z Tue Nov 19 2019


...Cascades and Northern Rockies...

A progressive upper level trough crosses the northern Rockies
through Saturday morning. The combination of elevated moisture and
upper level forcing as a jet streak approaches from the northwest
will generate moderate snow for the preferred terrain of the
northern Rockies of Idaho, Montana, and northwest Wyoming, with
localized maxima in excess of 4 inches possible.

...Upper Midwest and Great Lakes...

Warm air advection ahead of a cold front and upper level trough
will provide enough moisture and lift for 1 to 2 inches of snow
across portions of eastern Minnesota, Wisconsin, and the Upper
Peninsula of Michigan during the Day 2 period on Sunday.  Some
freezing drizzle is also possible with a few hundredths of an inch
of ice accretion southeast of the light snow area.

...Northeast...

There has been a westward trend in the 12Z guidance regarding the
track of the coastal storm off the East Coast by Day 3 (Monday). 
This will bring the storm closer to the New England coast with
light precipitation expected to make it farther inland across New
England and eastern New York.  Subfreezing temperatures will be
likely for the interior valleys Monday morning with warm air
advection occuring aloft, supporting freezing rain and some sleet
from east central New York to central Maine, and light snow closer
to the Canadian border.  Given cold low level temperatures in
place with warm advection occurring aloft at the same time, a
stripe of freezing drizzle/rain is possible from interior portions
of New England into central Maine. Depending on where this system
develops and tracks, parts of coastal Maine may have significant
amount of accumulation.

Hamrick