Subj : HVYSNOW: Probabilistic Heavy Snow And Icing Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jan 22 2025 19:11:41 FOUS11 KWBC 221911 QPFHSD Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 211 PM EST Wed Jan 22 2025 Valid 00Z Thu Jan 23 2025 - 00Z Sun Jan 26 2025 ....Great Lakes... Days 1-3... A clipper system tracking through Lake Superior today will lead to modest WAA-driven snow over the region from northwest to southeast tonight into Thursday. With the in situ air mass still plenty=20 cold, periods of light snow are expected with the passage of the=20 system with some lake enhancement as well. Cyclonic flow will=20 persist in the wake of the weakening clipper system which may=20 trigger a few lake snow bands off Lakes Superior and Michigan=20 tomorrow then off Lakes Erie/Ontario tomorrow night before snow=20 winds down. Lastly, another fast-moving clipper should brush=20 through the region D3 (Sat) with another round of light snow but=20 perhaps some modest amounts over the Keweenaw Peninsula. WPC=20 probabilities for at least 8 inches of the 3-day period are highest (>30%) over the Keweenaw, western Lower Michigan, and southeast of Lake Ontario. =20 ....The West... Days 1-3... Upper ridge axis just off the West Coast will reorient itself=20 westward, allowing height falls to sink through the near-interior=20 West Fri/Sat. Lead/weaker height falls on the southwest side of a=20 trough axis out of central Canada tomorrow will bring some light=20 snow to the northern Rockies with amounts generally 1-4". For days=20 2-3, height falls combined with a modest 120-kt jet moving through=20 MT will promote broad lift over the northern Rockies (Fri),=20 especially western MT into northwestern WY, with some local=20 enhancement/upslope. By D3 (Sat), the jet will increase over the=20 central Plains, favoring additional lift over the central Rockies=20 (southern WY into CO) with continued local upslope on easterly flow as high pressure noses down the western High Plains. Core of the=20 height falls will be farther west over NorCal/Great Basin but=20 moisture will be a bit lacking. Generally light snow is expected=20 over the northern/central Sierra and across northern NV/UT, though=20 this may increase toward the end of the period as the trough=20 sharpens and may close off into a closed low over NorCal late Sat. WPC probabilities of at least 8 inches of snow over the next three days are highest (>50%) over central Montana and northern Wyoming=20 (Little Belt, Big Snowy, Absaroka, and Big Horns) as well as into=20 the CO Rockies and southern WY (Medicine Bow and Park Range). For the days 1-3 period, the probability of significant icing=20 greater than 0.10" is less than 10 percent. Fracasso ....Winter Storm Key Messages are in effect. Please see current=20 Key Messages below... https://urldefense.com/v3/__https://www.wpc.ncep.noaa.gov/key_messages/Late= stKeyMessage_2.png__;!!DZ3fjg!8Ii1K-TB9siLZqPW2TdzuQALLYs9kRyu1tIITL9I7nMXg= y2R_BK66nRafQNgnOibq4tF4tQivh8bpDqVKV7J_t_nGs4$=20 $$ =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .