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FOUS11 KWBC 172007
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
307 PM EST Sat Jan 17 2026

Valid 00Z Sun Jan 18 2026 - 00Z Wed Jan 21 2026


...Great Lakes...
Days 1-3...

Shortwave trough passages in persistent cyclonic flow through the=20
Great Lakes will favor rounds of heavy lake effect snow for at=20
least the next week. The Great Lakes are currently mostly ice free
(total ice cover estimated at 15.5% on Jan 16), with surface water
temperatures between 2-6C (warmer over southern Lake Michigan and
Lake Ontario).=20

A long wave trough over Great Lakes tonight will shift east Sunday,
but reinforced by the next trough swinging around the anchored
upper low over the Hudson Bay. For D1, the highest probabilities
(40-70%) for more than 6 inches of snowfall is across the west-
central MI L.P. along the shores of eastern Lake Michigan, where=20
westerly flow and an inverted surface trough are expected to aid in
localized heavy snowfall.

The next reinforcing trough set to bring heavy snowfall during the
D2-D3 period is forecast to move in from the west with NWly flow=20
bringing more snow to the U.P. and most of the L.P. western shore.
Gusty winds up to 40 mph are also expected across the MI U.P,=20
which could lead to additional impacts associated with blowing=20
snow. SWly flow over Lake Erie pushes some single banding into=20
Buffalo, NY on Monday. These areas have Day 2 snow probs for >6"=20
in the 50-80% range. Then the next shortwave trough moves in from=20
the west Monday night with LES until ridging builds briefly late=20
Tuesday into the western Great Lakes. Day 3 PWPF for >6" is over=20
the eastern U.P. Most notably however, is single banding in=20
westerly flow over Lakes Erie and Ontario with Day 3 PWPF for >6"=20
60-90%. For the entire D1-D3 period, probabilities for >12" are
70-90% downwind of Lake Erie and Ontario, including the Buffalo
metro region.


...Southeast, Mid-Atlantic, Northeast...
Days 1-2...

Positively-tilted full-latitude trough this evening will move into
the Mid-South overnight, carrying a surface cold front through the
Southeast. By 12Z Sunday, cold front will be well into the Atlantic
with lagging precipitation over central/southeastern GA just in
advance of the sharp mid-level shortwave. With these cases, even
with surface temperatures just above freezing, dynamic cooling
could easily bring snow to the surface and accumulate via modest
rates 0.5-0.75"/hr per some of the CAM guidance. Though they have
wavered on how things come together, 12z guidance has nudged up
toward supporting a burst of snow over central/southeastern GA
which could accumulate to an inch or so (WPC probabilities of >1"
are around 10% but with upside potential). Light snow from a
dusting to half an inch is possible from the northern FL Panhandle
into upstate SC (>20-30% chance).=20

Further up the coast, precipitation will expand northeastward in=20
the right entrance of the >160kt jet atop marginal to cold=20
temperatures (milder along/east of I-95 in the Mid-Atlantic) and
increasing lower to mid-level FGEN. Elongated baroclinic zone and=20
areas of surface low pressure Sunday morning will coalesce into a
coherent surface low that is forecast to lift northeastward just=20
off the Mid-Atlantic coast to just outside the 40/70 benchmark Sunday
evening. 12Z guidance continued to trend westward with the QPF
axis/edge and have trended up in QPF and thus snow for the
Northeast. This could also keep shoreline temperatures milder for a
time before the low passes by. Snow could fall heavy for a period
over southern/southeastern New England Sunday evening per the 12Z
HREF (20-40% chance of >1"/hr rates). A swath of a few inches of=20
snow is likely from the Mid-Atlantic into the NYC area and New=20
England with upside potential over the terrain (Worcester hills,
etc.). WPC probabilities for at least 4 inches of snow are >50%
over eastern CT through RI and southeastern MA outside the Cape and
Islands. Into Maine, a stripe of a few/several inches of snow is
likely along the coast where probabilities for at least 4 inches of
snow are >40%.=20


...Northern Plains...
Day 1...

**Snow squalls likely across parts of the northern Plains on
 Sunday. Key Messages linked at the bottom of the discussion***

The next in a series of arctic cold fronts is forecast to dive
southward across the northern Plains on Sunday, with the greatest
potential for scattered snow squalls along the northern High
Plains. Timing for this front and associated snow squalls/streamers
behind the front starts in eastern MT/western ND during the=20
morning hours and quickly pushes southward into western SD and NE
into the afternoon. Lapse rates per several 12z CAMs near or exceed
6-7C/km for a brief period along the front and SNSQ parameters=20
rise above 4-5 between eastern MT and central NE. These parameters=20
combined with low-to-mid level FGEN intersecting with a healthy=20
100mb wide DGZ should allow for efficient snowfall rates within=20
these showers and bands. Wind gusts up to 60 mph are also possible=20
with this system, adding to the blowing snow potential.

Snow squalls are particularly dangerous for those traveling on
roadways, with extremely low visibilities and slippery conditions
developing rapidly. Be sure to slow down, turn on your lights, and
exit the highway if possible should you get caught in a snow
squall.


...Central High Plains...
Days 2-3...

With cold air banked over the High Plains/against the front ranges
of the Rockies ahead of a reinforcing shortwave trough Sunday=20
night through Monday, conditions will be set for a period of snow
over eastern CO to KS. Right entrance jet dynamics over the=20
existing front will allow banded snow to develop over central MT/WY
Sunday night with what appears to be the main banding early Monday
from northern CO terrain through western KS. The WNWly orientation
of these bands is parallel to the flow and should allow for=20
persistence of moderate to locally heavy narrow bands of snow. As=20
of now WPC probabilities for >2" are 10-20% along the KS/CO=20
border, but that is likely to increase as the system gets closer.=20
QPF trends has been up overall and a risk for 4" or more is=20
possible in these persistent banding scenarios.

Fracasso/Snell/Jackson


...Snow Squall Key Messages are in effect. Please see current Key=20
Messages below...

https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late=
stKeyMessage_2.png__;!!DZ3fjg!4O44Oh9C5u6tIlCTliLi6mxu8BcIbKtbjpq7987JV_82b=
OrTDGEDnOCpz0-LLQBikF8uV75kXdSRrKcBcTI-CQJ3RK0$=20



$$

=3D =3D =3D
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