Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
346 AM EDT Mon May 13 2019

Valid 12Z Mon May 13 2019 - 12Z Thu May 16 2019


...Northeast...

A closed upper low with anomalously low heights is expected to
support some late season high elevation snows across portions of
the Northeast beginning late Monday and continuing into early
Wednesday.

Rain changing to snow can be expected across some of the higher
elevations of the Catskills, Adirondacks and northern New England
ranges Monday night into Tuesday as a closed low, carving out
500mb heights 1 to 1.5 standard deviations below normal, moves
east from the Great Lakes into the Northeast.  Probabilities for
significant accumulations have increased some over the past
24-hrs, with WPC probabilities now showing a Slight Risk or
greater for accumulations of 4-inches or more across portions of
the Adirondacks, Green and White Mountains on Day 1 (ending 12Z
Tuesday).  The greatest potential for significant accumulations
remains centered along the northern White Mountains, particularly
across the Presidential Range, where WPC guidance is now showing a
Moderate Risk for accumulations of 4-inches or more on Day 1.

As a coastal low deepens over the Gulf of Maine, precipitation is
expected to continue across northern New England, with additional
snows likely for portions of the northern White Mountains, while
extending north into northern Maine during the overnight period
Wednesday night into early Thursday.

The probability of significant icing is less than 10 percent.

Pereira