FOUS11 KWBC 210923
QPFHSD

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
423 AM EST Wed Jan 21 2026

Valid 12Z Wed Jan 21 2026 - 12Z Sat Jan 24 2026

***At Least Major Winter Storm Impacts The South Friday Through
This Weekend, Expanding Up The East Coast Saturday Night***

...Southern Rockies, Southern Plains, Through the Mid-South and
Gulf Coast into The Tennessee Valley... Days 2-3...

Precip onset for major winter storm Friday on the Southern Plains
and Southern Rockies, quickly intensifying and expanding east over
the Mid-South and Gulf Coast states into the Tennessee Valley
Saturday. Expansive cold air mass spills down the Plains Thursday
night from 1052mb high pushing into North Dakota. Meanwhile, a
cutoff low under a deep ridge off the West Coast approaching
southern CA Thursday gets absorbed into the flow of a northern
stream trough dropping down the northern Rockies Friday making the
united trough full-latitude (through the length of the CONUS) by
Saturday. Subtropical East Pacific moisture ahead of the low trough
will spread across northern Mexico with Gulf moisture surging
north as early as Thursday night. Persistent Pacific and Gulf
moisture overrunning the arctic-sourced airmass will result the
full wintry p-type scenario from plain rain near the Gulf Coast to
freezing rain not too far inland, to sleet north of that and
finally snow where the warm nose remains subzero. The main notes
for the 00Z cycle is a northward shift in both QPF and the thermal profiles/warm nose. However, the surface cold air should continue
to progress so in a sense the broadness of the winter weather swath
is still expanding (stretching from the Gulf Coast to the central
Plains). The precip intensification Friday night through Saturday
will be remarkable over the southern Plains and Mid-South with
heavy rates and likely catastrophic impacts for at least local
scales given the risk for over an inch of ice accretion and deep
snow with heavy sleet in between. Residents should prepare for
prolonged power outages that occur during the coldest air of the
season. Please monitor the forecast for your area via weather.gov.
With so much heavy precip occurring just after the WWD time range
ending 12Z Saturday, probabilities will be presented through 00Z
Sunday (Day 3.5). Day 3.5 PWPF for > 8" is 50-80% across much of
the central/southern CO Rockies through the central NM ranges with
a wide swath of 20-50% from much of OK, northern AR along the TN/KY
border to the southern Appalachians. Day 3.5 PWPF for >0.5" is
20-50% from northeast TX across the LA/AR border and northern MS
and northwest AL.

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

Sprawling Hudson Bay vortex dominates the continental pattern
through this week. Within the broad cyclonic pattern, a pair of shortwaves/clippers cross the Great Lakes through tonight with
associated 850-700 mb frontogenesis driving east-west oriented
snow bands over WI again and the Great Lakes. Day 1 PWPF for >4"
is 50% over southwest MI, northwest PA/western NY and over the Tug
Hill and Mohawk Valley. Northern lake LES continues then through
Friday. Day 2 PWPF for >4" is 50-80% for the Keweenaw and eastern
U.P., northern L.P., and the Tug Hill to the western Adirondacks.
These values diminish Saturday under surface ridging under the core
of the Arctic cold.

Jackson

...Winter Storm Key Messages remain in effect for extreme cold and
a major winter storm for the south. They are linked 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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