Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
355 PM EST Thu Nov 07 2019

Valid 00Z Fri Nov 08 2019 - 00Z Mon Nov 11 2019


Days 1-3...

...Northeast...
Light snow along the back edge of a broad area of precipitation
will continue to slide east across the Northeast into the evening
hours on Thursday.  Low pressure developing over the Gulf of Maine
is expected to track quickly into Atlantic Canada overnight. 
Overall, expect additional snowfall accumulations to be light. 
After 00Z Thursday - with the exception of eastern Maine, WPC
probabilities show little threat for additional amounts greater
than 2-inches.

...Great Lakes...
Northwest flow/cold air advection will continue to support lake
effect snow showers through Thursday night into Friday, with
locally heavy amounts across portions of the central U.P. and
northwestern Lower Michigan.  Guidance continues to show lake
effect snow showers developing and extending from Lake Huron
across Lake Erie, producing several inches of snow across a small
portion of northwest Pennsylvania and western New York.    Lakes
effect snows will diminish as winds back to the southwest across
the upper Great Lakes during the day on Friday and the lower Great
Lakes by Friday evening.

...Northern Rockies/High Plains...
A shortwave trough diving south into central Canada and the
northern U.S. Plains will drive a cold front southwest through
Montana late Saturday into Sunday.  Post-frontal upslope flow
along with low-to-mid level frontogenesis will support light to
moderate snows extending across Montana into the western Dakotas
Saturday night.  This may produce some locally heavy totals,
especially along the ranges of central and northwestern Montana.  


For Days 1-3, the probability of significant icing (0.25 inch) is
less than 10 percent.

Pereira