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FOUS11 KWBC 160800
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Sun Nov 16 2025

Valid 12Z Sun Nov 16 2025 - 12Z Wed Nov 19 2025

...Northeast/Great Lakes...
Days 1-2...

A vigorous shortwave will slide east of the Great Lakes this
morning, with a closed upper center forecast to develop over New
England later today. At the surface, a low pressure center is
expected to redevelop along the Maine coast this morning and track
east into southern New Brunswick by this evening. This track will
support snow across interior Maine, with rain along the coast,
followed by a transition to snow as far south as Downeast Maine as
the low tracks into Canada. The heaviest amounts across Maine are
likely to center over the North Woods, with WPC probabilities
continuing to indicate that amounts over 4 inches are likely to
cover the region, with locally heavier amounts over 8 inches
possible in the higher terrain.

Meanwhile, any lingering mixed precipitation from the overnight
falling over northern New York, Vermont, and New Hampshire is
likely to transition to all snow early in the period, with upslope
snow beginning to ramp up this morning. Little change to the
previous forecast, with northwest flow targeting parts of the
northern Adirondacks, Greens, and Whites with the best chance for
significant accumulations. The heaviest accumulations are expected
today. But with some additional accumulations continuing through
Monday, two day totals likely expected to top a foot in some
locations, especially in the northern Greens and the Presidential
Range.

The cold air advection and west-northwesterly to northwesterly
flow will support multiple lake effect bands off of Lake Ontario,
producing some locally heavy totals around the Finger Lakes. A
narrow intense single band with connections to lakes Superior and
Huron may set up downwind of Lake Erie, resulting in some locally
heavy totals near the far western New York-Pennsylvania border
into northwestern Pennsylvania. These are reflected in some higher
WPC probabilities for snowfall amounts exceeding 4 inches in those
areas.

...California to the Central and Southern Rockies...
Days 1-3...

A pair of upper lows will impact the region this period. The first
system, which is currently, producing widespread precipitation
across central to southern California and parts of Nevada and
Arizona this morning, is forecast to lift northeast across
southern California into the Great Basin later today, before
continuing east across the central Rockies tonight into early
Monday. This will be followed by a highly amplified shortwave
dropping out of the northeastern Pacific, with a closed low
developing near the northern California coast tomorrow. This second
system is then expected to continue to drop south, moving into
southern California on Tuesday.

For the leading low, additional accumulations of 6 inches or more
are likely for parts of the Sierra Nevada, mainly for areas above
9000 ft in the southern Sierra and above 7000 ft in the central to
northern Sierra. Farther to the east, this system may produce
similar totals, mostly for areas above 9000 ft, across the southern
Utah mountains and the Rockies from areas as far south as the San
Juans to as far north as the Teton and Wind River ranges.

Heavy accumulations with the second low will focus mostly on the
Sierra Nevada once again, with early Monday to early Wednesday two-day
totals expected to exceed 8 inches for many areas above 7000 ft in
the central Sierra. Some of the higher elevations in the central
and southern Nevada and the southern Utah mountains, as well as
the San Juans could also see locally heavy totals.

Pereira

$$