FOUS11 KWBC 221959
QPFHSD

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

Valid 00Z Fri Jan 23 2026 - 00Z Mon Jan 26 2026

...Major winter storm to bring the potential for crippling icing, significant sleet, and heavy snow from the Southern Plains through
the Southeast and up the Atlantic Coast into New England...

The event will begin Friday morning across the Southern Plains. The
driver of this event is an impressive overlap of intensifying
synoptic ascent with increasing subtropical moisture.

The synoptic pattern becomes favorable Friday in response to the
evolution of multiple shortwaves rotating through an amplifying
trough across the eastern CONUS. A closed 500mb low off the Baja
Peninsula will begin to open and shear to the east, at the same
time dual shortwaves dig out of Saskatchewan/Alberta and into the
Northern Plains. As the northern shortwaves dive south and the Baja
low ejects east, the interaction of these features will lead to
increasing mid-level divergence overlapping pronounced height falls
to produce rich deep layer lift. This will be on top of an arctic
cold front that will be sagging southward into the Southern Plains
and eventually work its way southeast to the Gulf and Atlantic
coasts by Saturday. This overlapping ascent will materialize atop a
moistening column as subtropical moisture downstream of the Baja
low streams northeast reflected by IVT that reaches above the 97th
percentile according to NAEFS, in a broad swath from Texas to the
Carolinas, with above the record (CFSR at 00Z) climatology by
Sunday evening in the east.

This increasing moisture will result in a large swath of
precipitation expanding from the Southern Plains Friday, to the
Mississippi Valley and Tennessee Valley Saturday, into the
Carolinas and Mid-Atlantic by Sunday, and finally reaching the
Northeast Sunday night. This is a very large and impactful system
across a huge portion of this country. While impacts will be
considerable in many areas (aided by extreme cold), the icing (and
sleet) and snow will be most impressive across two distinct areas.

Freezing Rain and 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 enhanced by pronounced mid-level confluence over the Great
Lakes and New England) 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,and in some
places this re-freezing layer is above the 90th percentile in terms
of depth, suggesting some locations will experience exceptional
sleet accumulations.

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", (WPC probabilities above
50% for 1" if ice) which would almost certainly 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. The consistency of the guidance in both
placement and amounts for this area are resulting in high
confidence in an extreme event, leading to long-lasting impacts
both to travel and infrastructure due to the bitterly cold airmass
expected to linger into next week over the region.

Heavy icing is also expected farther east into the southern
Appalachians and southern Mid-Atlantic. 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. While regional soundings indicate there may be
considerable sleet in this area as well, especially across southern
VA into northern NC, these CADs are notorious for their effective dry/isallobaric flow, enhanced by precipitation, leading to dry
wet-bulb advection offsetting the latent heat of freezing during
freezing rain. With such an impressive high in place at
precipitation onset, this will likely result in considerable
accumulations of sleet and freezing rain here, too, with WPC
probabilities indicating a moderate risk (50-70%) of at least 0.5",
highest across the Piedmont. The guidance has trended just a bit
colder this afternoon, but significant icing is also possible as
far north as Richmond, VA and towards the Chesapeake Bay.

Heavy Snow:
North of the mixed precipitation area and closely tied 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,
Mid-Atlantic, and reaching the Northeast by Sunday evening (with
additional expansion beyond this forecast period).

Favorable upslope flow as the strong arctic high pressure noses
southward along the High Plains behind a strong cold front 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 through WAA/fgen intersects with a
region where the DGZ is forecast to be extremely deep (SREF
probabilities above 70% for >100mb of depth). This would allow for
efficient formation of dendrites where ample lift can fully
moisture the column. While this depth is impressive, regional
forecast soundings indicate that the best ascent may lie below this
DGZ in many areas, and there is only modest indication of any
isothermal layer beneath the DGZ to maintain aggregates. Despite
this, efficient and fluffy SLRs are likely in this area, and with a
long duration event expected, WPC probabilities are moderate
(30-50% )for at least 12 inches from eastern KS and OK into
southern MO, with widespread 4+ inches extending all the way back
into the TX Panhandle and lower MS VLY.

Farther east, some heavier snowfall is becoming more likely for
parts of the Ohio Valley, and into the Mid-Atlantic, and especially
Northeast. Here, pronounced WAA and accompanying 850-700mb fgen
will drive pronounced ascent into a rapidly moistening column
thanks to IVT above the 90th climatological percentile. As the
upper trough (interaction of the southern and northern streams)
deepens over the Plains, downstream ascent will maximize and a
period of impressive WAA snow with snowfall rates >1"/hr are
likely. As secondary low pressure develops offshore (in a Miller B
type evolution), banded structures within the WAA are likely to
translate northward from the Mid-Atlantic into New England, and
then may pivot and drift eastward Sunday night into Monday. Where
this occurs, the heaviest total snowfall accumulations are
probable, reflected by WPC probabilities that are already above 50%
for 12+ inches, and this is even with more of the event beyond this
forecast period (into New England). While there is some uncertainty
into how much mixing will pivot northward, especially closer to the
coast from Richmond, VA through Long Island, the interior portions
(NW of I-95 and into southern New England which will remain cold as
the secondary low develops and tracks near the 40/70 Benchmark)
will remain all snow with above-climo SLRs leading to significant
snowfall accumulations. Many areas are expected to receive more
than 12 inches from the Ohio Valley through the Mid-Atlantic and
into the Northeast before this system winds down on Monday /D4/.

Key Messages for this system are linked below (Key Message 2)

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

Expansive mid-level low centered over the Hudson Bay will track
slowly southward this evening and then begin to shear open and
translate to the east as a secondary shortwave rotates through its
base and atop the Great Lakes Friday evening. Behind this impulse,
shortwave ridging will amplify across the area, bringing an end to
the persistent CAA and associated lake-induced ascent.

The subsequent W/NW flow and accompanying CAA will lead to
impressive lake effect snow (LES) in the favored W/NW snow belts
D1, with some pivoting to more N/NW D2 before waning. The heaviest
snowfall is likely east of Lake Ontario D1 where WPC
probabilities indicate a high risk (>70%) for at least 12 inches,
and 1-2 feet is possible across the Tug Hill Plateau. Elsewhere,
WPC probabilities suggest a moderate risk (50-70%) for at least 4
inches along the Chautauqua Ridge, western MI (east shore of Lake
Michigan) and across the northern U.P. During D2 the precipitation
intensity will weaken, but WPC probabilities suggest a moderate
risk (30-70%) for at least 2 inches in far NW IN and southeast of
Lake Ontario, before the shortwave ridging brings an end to this
round of LES.

Additionally, and this pivots into the Northeast as well, a second
round of snow squalls is possible on Friday along and behind an
arctic cold front traversing the region. For more details on the
snow squall threat in the Northeast through Friday, please refer to
our Key Messages (Key Messages 3) below.

Snell/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

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

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

$$
--- SBBSecho 3.28-Linux
* Origin: Capitol City Online (618:250/1)