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QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
345 AM EST Thu Jan 22 2026

Valid 12Z Thu Jan 22 2026 - 12Z Sun Jan 25 2026

***Significant Winter Storm To Bring Potentially Crippling Impacts
To Parts Of The South Friday Through This Weekend, Expanding Up
The East Coast Saturday Night Into Sunday***

...Southern Rockies and Southern Plains through the Ohio/Tennessee
Valleys into the Mid-Atlantic... Days 2-3...

Estimated over 130 million residents under winter weather headlines
this morning as confidence continues to increase on a highly
impactful and extremely wide- reaching winter storm to begin on
Friday across the south-central U.S., eventually pushing towards
the East Coast by Saturday night into Sunday. Guidance has nearly
unanimously converged on the upper low churning just west of
southern CA (sampled by recon aircraft for the recent 00z model
suite) to eject eastward ahead of a diving northern stream
shortwave and fully phase by the day 4 timeframe. Uncertainty
remains associated with the speed of the approaching northern
stream trough, which eventually leads to the amplified pattern in
the central/eastern U.S.. However, this uncertainty has decreased
tonight as guidance converges on cluster 1 from WPC's 12z 1/21
clusters. Some guidance remains more amped (CMC/ECMWF) than others
(GFS) and leads to some lingering uncertainty regarding the
northern extent of heavy QPF and the mid- level warm nose. However,
all scenarios now point to a large QPF footprint falling in the
form of frozen precipitation and resulting in a significant winter storm.

The aforementioned southern CA upper low will help surge ample
Pacific moisture (above the 90th climatological percentile per the
12z NAEFS) into the southern U.S. by Friday night, where a deep
arctic airmass is placed in ideal position for overrunning and
wintry precipitation. This arctic airmass in place is brought to
the region by a near record 1050mb surface high pressure over the
Northern Plains on Friday. As time progresses this high pressure is
expected to moderate and evolve into more of a "banana" look,
which is classic for heavy winter precipitation in the East as
low-levl cold air continues to sink southward towards a stationary
front forecast to stretch along the Gulf Coast. A few weak areas of
low pressure are forecast to form along this front before gradually
lifting northward into the TN Valley and along the Carolina
coastline by the end of D3. Decided to split up the remainder of
the discussion into hazard- type categories given this event covers
such a massive amount of real- estate. For local forecasts and
more details, read your local WFOs AFD.

Heavy Freezing Rain/Sleet...
Arguably the most lasting impact associated with this winter storm
could be from heavy accumulating freezing rain and sleet
stretching from the southern Plains, Mid-South, Tennessee Valley,
and southern Mid- Atlantic. This is due to very cold low-level
arctic air being reinforced by the strong high over the north-
central U.S. and a warm nose aloft (at around 750mb per cross
section model soundings) melting snow as it falls through the
column before refreezing just before or at the surface. The
greatest freezing rain amounts and impacts are currently forecast
across northeast TX through northern MS as favorable thermal
profiles linger for over 24 hours beginning Friday night. WPC
72-hour probabilities for >0.5" of freezing rain are high >70%
across southern AR into parts of northwest MS. Here, ice accretion
could be crippling and exceed 0.75-1.00", which would very likely
lead to widespread long- lasting damage to infrastructure,
including power outages and tree damage. Major sleet accumulations
are also likely just north of the freezing rain area stretching
from southern OK/north TX through central AR and into the Mid-
South, with more than a few inches of sleet possible. This could
make for treacherous driving conditions and lasting travel impacts
due to the bitterly cold airmass expected to linger into next week
over the region.

Heavy icing is also likely into the TN Valley and nearby southern
Appalachians and Mid- Atlantic, where freezing rain continues
beyond the D3 timeframe. The setup across the southern Mid-Atlantic
down as far south as northern GA and areas just inland from the
coasts of the Carolinas is an extreme case of CAD with a 1040mb
high situated over the Interior Northeast on Saturday night. This
high pressure filters very low/dry dew points with values below
zero prior to precip onset late Saturday. This cold air wedge
remains sharply locked in place at the surface for the remainder
of the event as 700-850mb temperatures begin to increase well above
freezing by the end of D3 throughout the Carolinas and northern
GA. WPC probabilities for >0.25" of freezing rain accretion through
12z Sun. are currently 40-70% from northern AL/TN through northern
GA and into the Midlands of SC and areas just inland of the NC
Tidewater region. Heavy sleet accumulations are also possible where
the low-level column remains colder into VA Piedmont.

Heavy Snow...
North of the mixed precipitation area and closely tide to both a
favorable LFQ of a zonally oriented 180kt upper jet and strong
700mb fgen, snow is the primary precipitation type stretching from
the southern High Plains of east-central NM and the southern
Rockies through the Plains, Mid-Mississippi Valley, Ohio Valley,
and Mid-Atlantic by Sunday morning. Favorable upslope flow as the
strong arctic high pressure noses southward along the High Plains
starts on Friday across the southern Rockies, with light snow and
even a chance for freezing drizzle at onset across the central
Plains until the column fully saturates. Heavy snow is then
forecast to begin breaking out Friday night from the
central/southern Plains through the mid-Mississippi Valley and
spanning much of the Ohio Valley and parts of the Midwest on
Saturday. Snowfall rates could near 1"/hr as strong lift intersects
with a region about 150 miles north of the mixed precip zone where
the DGZ is forecast to be extremely deep (about 500 mb per areal
average soundings). This would allow for efficient formation of
dendrites where ample lift can fully moisture the column. Should a
region remain in this zone for a longer enough period it's not out
of the realm of possibility 30:1 snow ratios are observed.
However, most locations appears to progressively see this favorable
DGZ move east-northeast with time and shrink as mid-level
temperatures increase above -8C and allows for more needles than
dendrites. WPC probabilities for >6" of snow through 12z Sun. are
medium to high (30-70%) stretching from east-central NM and the TX
Panhandle across northern OK, into the Mid-Mississippi Valley.
These probabilities increase to above 70% in the Ohio Valley,
where 8-10" of snow is possible. The widespread nature of this
heavy snow is likely to significantly impact both ground and air
travel in the region.

One area that is slowly becoming the most favorable location for
heavy snowfall rates and potentially the most impressive snowfall
amounts is the central Appalachians, northern VA, MD, and southern
PA through early Sunday. As the upper level trough deepens over the
central U.S. Saturday night, mid- level flow begins to increase
out ahead of it and meets the mid-level warm front stretching from
the eastern Ohio Valley into the Mid- Atlantic. Several 00z models
highlight increasing 700mb fgen over the eastern Ohio Valley and
into central VA by late D3, which supports the potential for an
extended period of 1"/hr rates across much of eastern WV,
central/northern VA, MD, and southern PA. The 0C warm nose may
begin to approach northern VA by the end of D3, but areas just to
the north could see 6-12" by sunrise on Sunday as precipitation
lingering further into the day on Sunday. Snow ratios will also be
favorable at onset and could potentially exceed 20:1 within
enhanced banding, which is well above the 11:1 climatology in the
region. Current WPC probabilities through D3 are medium to high
(40-70%) for at least 8" of snow, this includes areas just west of
I-95 from D.C. to Baltimore. Heavy snow is expected to continue
stretching into the Northeast and New England on Sunday, see WPC's
Extended Forecast Discussion for more. Also, see the Key Messages
linked at the bottom of this discussion.

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

A Hudson Bay vortex pivoting south through Ontario will sustain the
seemingly endless cyclonic flow over the Great Lakes and their
usual snow belts before strong high pressure builds overhead on D3
and ends this lake effect pattern for the time being. 500mb
heights associated with this powerful upper low are quite anomalous
(below the 1st climatological percentile per 12z NAEFS in southern
Ontario Thursday into Friday night). WPC probabilities highlight
medium-high chances (>60%) for snowfall totals >6" over the
northern tier of the U.P., along the Chautauqua Ridge on north
into western NY, and down wind of Lake Ontario over the Tug Hill.
The Tug Hill most notably will continue to receive very heavy snow
over the next few days highlighted by WPC 48-hour probabilities
sporting high chances (>70%) for >8" in the Tug Hill.

A growing concern is for snow squalls over the Northeast. WPC
initiated Key Messages for what appear to be multiple rounds of
snow squalls from western NY on east through New England, with some
squalls possible as far south as northern PA early today. This is
highlighted well in CAMs snow squall parameter, with highest
potential on Thursday from western PA through central NY. The
final round of squalls are expected on Friday as an arctic front
traverses the region, causing steep lapse rates and focused
vertical ascent. This front will also usher dangerously cold
temperatures and wind chills. For more details on the snow squall
threat in the Northeast through Friday, please refer to our Key Messages.

Snell

...Winter Storm/Snow Squall/Extreme Cold 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

https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_3.png

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