Subj : HVYSNOW: Probabilistic Heavy Snow And Icing Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Oct 09 2023 08:47:51 FOUS11 KWBC 090847 QPFHSD Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 445 AM EDT Mon Oct 09 2023 Valid 12Z Mon Oct 09 2023 - 12Z Thu Oct 12 2023 For Days 1-2, the probability of significant snow or ice accumulation across the contiguous U.S. is less than 10 percent. ....Day 3... Northern Rockies... A mid-upper level trough will move from the Pacific Northwest Tuesday night to the central/northern Rockies by Wednesday night. Meanwhile, a near 110-kt jet positions itself across Nevada/Utah, putting portions of the Intermountain West to Northern Rockies in the favored left-exit region. A front crossing the region will bring colder air with 700 mb temperatures falling below 0C, lowering snow levels initially from 9000+ ft to around 7000-7500 ft. By early Thursday, as the core of the upper low settles over the region, the colder temps combined with a lingering surface trough will enhance precipitation, particularly across portions of WY. WPC probabilities for Day 3 (12Z Wed-12Z Thu) for at least 4 inches are between 10-40 percent for portions of the Colorado Rockies, the Utah Unitas, and portions of the Snake River region and southwest Montana mountains. Probabilities for at least 4 inches are highest (40-70+ percent) for western Wyoming ranges including Tetons, Wind River, and the Big Horns with the greatest probabilities above 8500-9000 ft where probabilities for at least 8 inches are 10-20 percent. Taylor $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .