Subj : Major Winter Storm Expect To : All From : Mike Powell Date : Wed Jan 21 2026 08:56:59 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 $$ --- SBBSecho 3.28-Linux * Origin: Capitol City Online (618:250/1) .