FOUS11 KWBC 180559
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
159 AM EDT Sat Apr 18 2026

Valid 12Z Sat Apr 18 2026 - 12Z Tue Apr 21 2026

...Upstate New York/Northern New England... Day 2...

A strong cold front driven by a potent vorticity streamer/shortwave
embedded within larger cyclonic flow centered over the Great Lakes
will race eastward across Upstate NY and New England early on
Sunday. The cold front likely outraces the accompanying mid-level
trough axis, which results in continued SW flow aloft, keeping
sufficient moisture present in the column as the low-level thermals
cool dramatically. This suggests that precipitation ahead of the
front, which will be rain, will rapidly transition to a period of
snow behind the front, especially in the higher elevations of the
Adirondacks, Greens, and Whites. The duration of snow after
changeover will be limited due to subsequent column drying, but NW
flow in the wake of this front will promote at least a period of
upslope enhancement to slow the drying enough for a few inches of
snow in these higher elevations. WPC probabilities have been
consistent the past few runs, and continue to suggest a 10-30%
chance for at least 4 inches of snow in the higher terrain from
northern Upstate NY through VT, NH, and western ME.

The probability for significant freezing rain exceeding 0.1 inches
across the CONUS is less than 10 percent.

Weiss
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