FOUS11 KWBC 290746
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
246 AM EST Thu Jan 29 2026

Valid 12Z Thu Jan 29 2026 - 12Z Sun Feb 01 2026

...Great Lakes... Days 1-2...

Continued cyclonic flow will continue to favor lake effect snow
across the Great Lakes for another couple of days. Frigid 850mb
temperatures will persist with temperatures around -18 to -24C,
which are below the 10th climatological percentile. WNW flow
will turn more northerly (or NNE) as the sharp 500mb shortwave
passes through later today. On Friday, northerly flow continues
Friday with NNE flow possible into Chicagoland carrying a band
into the region overnight into Saturday. Most snow winds downs
late Saturday into early Sunday with a surface high overhead.
Single band off Lake Ontario will weaken later today but persist
through Friday.

For days 1-2, WPC probabilities for at least 6 inches of snow are

50% over parts of the Michigan U.P. and downwind of Lake Ontario

near Oswego, where over 10 inches is possible. Over Chicago, WPC
probabilities for at least 4 inches are not quite 30% but some CAM
guidance shows a farther westward push out of NW Indiana than others.

...Cascades & Olympics... Days 1-2...

A series of storm systems tracking into the Gulf of Alaska will
direct rounds of moisture and WAA at western WA through the
remainder of the week. Strong upslope flow should support locally
heavy snowfall totals above 5,000ft. Snow levels approach
6,000-6,500ft by Friday into Saturday in western WA as precipitation ends.

...Northern & Central Plains... Days 1-3...

A weak Pacific shortwave trough tracking NW-SE will ride along a
nearby 850mb front to support periods of snow from the northern
High Plains on south in the the central High Plains. Guidance is
even keying in on an area of 700mb FGEN over the Black Hills on
south into the Nebraska Sand Hills that could support moderate snow
bands Friday morning. Snow is not expected to be overly heavy,
although the Black Hills through orographic lifting and some
localized banding may be able to see snowfall amounts surpass 6".
This is supported in WPC probabilities which show 60-80%
probabilities for >4" of snow in the Black Hills, and low-to-
moderate chances (20-50%) in their peaks for >8". Elsewhere, from
eastern MT on south and east through the Missouri River Valley,
most snowfall accumulations are likely to range between 1-3". Even
some localized instances of freezing rain in the northern High
Plains on late Friday into Saturday given the favorable overrunning
from WAA at low-mid levels and sub-freezing surface temps. Some
hazardous travel is possible, especially where roads temperatures
are likely below freezing in the wake of the recent extreme cold.

...Southern Appalachians & Mid-Atlantic... Days 2-3...

...Confidence growing for a major winter storm & heavy snowfall
across the southern Mid-Atlantic...

Models continue to point to an anomalous and impactful event for
the southern Appalachians and especially southern Mid-Atlantic
states this weekend, aided by record cold into the
Southeast/Florida. Though the various models/ensembles have wavered
in their evolution and track of the system, nearly all show a
powerful ocean storm that will affect the southern Mid-Atlantic as
cyclogenesis ensues.

As a very deep 500mb low approaches the region, exceptional PVA
and WAA over the Mid-Atlantic coast will spawn low pressure along
the strengthening coastal front. Increasing 700mb Q-vector
convergence near the NC Outer Banks will foster healthy mid-level
ascent beneath the diffluent left-exit region of a >100kt 500mb jet
streak located at the base of the closed 500mb low. As the 700mb
low tracks towards the Cape Fear region Saturday night, the axis of
heaviest snowfall will reside on the 700mb low's northern and
western flank while surface low pressure explosively deepens into
the 970s mb by Sunday morning. Snow will likely fall heavily at
times over eastern NC late Saturday into early Sunday west of the
surface low as the mid-level upper low eventually catches up. In
addition, winds will increase which will create blowing and
drifting snow with possible blizzard conditions. Snow will also
expand northeastward up along the Mid- Atlantic coast into Long
Island and southern/southeastern New England but with a lot of
uncertainty in the expanse of the precipitation shield.

Through 12Z Sunday, WPC probabilities for at least 8 inches of
snow are >50% over the southern Appalachians, much of central to
eastern NC, as well as southern VA and northeastern SC. Within this
region, WPC probabilities for at least 12 inches of snow are >40%
over eastern NC. The footprint of impactful snowfall (>2" to the
south) extends into northeastern/eastern GA, through much of SC
(except for the Lowcountry where ptypes/thermals are more
uncertain), and as far north into the DelMarVa and southeastern NJ.

The Probabilistic Winter Storm Severity Index (WSSI-P) shows >50%
chances for Major impacts from the NC/SC border to southeastern VA.
These elevated WSSI-P Major probabilities indicate an unusual/rare
event is increasingly likely.

The probability for significant icing is less than 10 percent.

Fracasso/Mullinax

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

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

https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_2.png

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