FOUS11 KWBC 210715
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
315 AM EDT Sat Mar 21 2026

Valid 12Z Sat Mar 21 2026 - 12Z Tue Mar 24 2026

...Northeast...
Days 1-2...

A clipper system will move southeast out of central Canada and into
the Northeast this weekend. Snow on the leading edge of the
precipitation shield will move into upstate New York this evening,
then spread across New England tonight. The snow will be
characterized by warm advection. With a high sun angle and
plentiful warm air over much of the eastern half of the country,
the warm air will move into New York and southern New England,
resulting in a changeover to rain on Sunday over much of upstate
New York and into southern New England. Meanwhile, over most of
northern New England, the predominant precipitation type remains as
snow as the back edge of the precipitation quickly pushes east
across New England.

The southwesterly flow of warm air will be uplifted by the terrain
of the Adirondacks, Green, and White Mountains. Here, the
combination of upslope and cooler temperatures at higher
elevations will support multiple inches of snow. The heaviest snow
will fall between early Sunday morning and Sunday evening. In the
valleys, warmer temperatures, high sun angle, and snow mostly
falling during the day should all work to keep snow totals much
lower than the adjacent mountains, though still reaching into
advisory criteria. Where snow rates remain lighter, accumulations
during the day should be greatly tempered, and largely confined to
grassy areas.

WPC snowfall probabilities for the storm total snow over 4 inches
are high (over 70%) from the northern Adirondacks east across the
northern Greens of Vermont, northern Whites of New Hampshire, and
much of southern Maine. For much of northern New Hampshire and
western Maine, those probabilities are above 90% for 4 inches and
over 70% for 8 inches. As typical with compact storms, the exact
longevity and intensity of any internal heavy snow bands will
dictate where the highest snowfall totals are observed.

By D3/Monday, a secondary coastal low is expected to form south of
Long Island. The precipitation shield will be narrow and focus
across southern New England, where temperatures will be warm enough
for mostly (or entirely) rain. Thus, the chances for impactful
snow on Monday anywhere in the Northeast continue to decrease.

The chances for significant icing across the CONUS is less than 10
percent.


Wegman



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