FOUS11 KWBC 050819
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
319 AM EST Thu Feb 5 2026

Valid 12Z Thu Feb 05 2026 - 12Z Sun Feb 08 2026

...The Carolinas... Day 1...

A deep shortwave trough will track across the northern Gulf and
then off the Florida coast through this aftn. This will help
strengthen secondary low pressure off the coast of the Carolinas,
with some lingering moisture extending back onshore, at least
through the morning. However, forecast soundings indicate that
pronounced dry air above the surface will inhibit much in the way
of precipitation. However, what does fall, will occur in a sub-
freezing column, leading to a continuation of very light freezing
rain or freezing drizzle for a few hours after 12Z across the
eastern Carolinas. This is reflected by WPC probabilities that
indicate a 10-30% chance (locally 50% chance) of more than 0.01" of
ice, highest from Cape Fear through the Outer banks.

...Great Lakes, Central Appalachians, Northeast, Mid-Atlantic... Days 1-3...

A fast moving shortwave diving out of Manitoba will race southeast
today, reaching the Mid-Atlantic states by Friday morning. This
lead impulse will be followed almost immediately by a second, more
strung out, shortwave, with this secondary impulse responsible for
driving a strong arctic cold front southward beneath it. This
secondary impulse will help develop a surface wave of low pressure
across Upstate NY Friday evening, with this low scooting rapidly
eastward to off the New England coast by the end of D2. The lead
cold front will trail off this low, with a secondary reinforcing
surge of arctic air occurring Saturday behind a secondary front.

Together, these features will result in an extended period of
moderate ascent, but in an environment with normal to below normal
PWs on the sharpening NW flow. Although the moisture will be
modest, the forcing will be sufficient to wring out snowfall across
the area, although most accumulation will be very light. There may
be a few exceptions:

1) Upslope snow into the Central Appalachians. This is expected
behind the first cold front beginning Friday aftn and then
intensifying Friday night before waning Saturday evening.
Intensifying N/NW flow will become quite strong and direct into the
terrain, with the cooling column providing a deepening DGZ into
which this ascent will maximize. Although atmospheric moisture is
modest, this flow will direct at least some Great Lakes enhanced
moisture to improve the potential for heavy upslope snowfall.
Initially, Froude numbers Friday and Friday night suggest critical
or blocked flow indicating the heaviest snowfall will be along or
just upwind of the Appalachians crests, but as flow becomes
unblocked on Saturday, more snow may spill over towards the east.
Still, the heaviest accumulations are likely in the higher terrain
and upwind areas, where WPC probabilities for the entire event
suggest a high risk (>70% chance) for at least 8" of snow, with
locally 12+" possible (30% chance).

The increasing W/NW flow behind the arctic front will also support
some enhanced lake effect snow (LES), especially in the favored
more N/NW snow belts south of Lake Ontario and Lake Superior. LES
is not expected to be extremely heavy or prolonged, but WPC
probabilities indicate a 70-90% chance for at least 4" south of
Lake Ontario, and a 30-50% chance across the eastern U.P. of Michigan.

Finally, as a surface low strengthens well offshore and east of
the Mid-Atlantic states, increasing NW flow with a potential
inverted trough will focus some moisture and ascent across eastern
New England from near Portland, ME southward to Cape Cod, MA. The
combination of onshore flow and ocean effect snow combined with the
potential focused inverted trough may enhance snowfall along the
coast. The intensity of this snowfall is still quite uncertain as
most of it is early D3, but these inverted troughs can sometimes
pivot favorably for locally much heavier snowfall. Confidence is
modest at this time range due to wide variations in the models, but
current WPC probabilities indicate a 50-70% chance for at least 4"
of accumulation from Cape Ann southward through Cape Cod,
including the Boston metro area.

Finally, although not expected to be widespread, scattered snow
squalls are possible along the arctic front as it digs southward
Friday night into Saturday across the Northeast. Any convective
snow showers or squalls that develop will contain brief heavy snow
rates and strong winds, leading to hazardous travel.

Extremely cold temperatures this weekend have also prompted the
issuance of Key Messages related to this event. Those are linked below.

Weiss

...Winter Storm Key Messages are in effect. Please see current
Key Messages below...

https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_1.png

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