Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 255 PM EST Fri Feb 09 2024 Valid 00Z Sat Feb 10 2024 - 00Z Tue Feb 13 2024 ...Western U.S.... Days 1-2... Models continue to advertise a split in the upper pattern across the western U.S. developing over the next day. A well-defined shortwave diving into the base of a broad upper trough is expected to carve out a deep southern stream trough over the Four Corners on Saturday. Meanwhile in the northern stream, a trough is forecast to progress from the northern Rockies to the Plains. The digging southern stream wave is expected to support high elevation snow from the Great Basin into the Southwest and southern Rockies. While widespread heavy accumulations are not expected, there is the potential for locally heavy high-elevation amounts. These areas include the southern Utah and the southeastern Arizona mountains, where WPC PWPF indicates local snow amounts of 8 inches or more are possible. As the upper trough continues to move east, increasing convergence/upslope flow supported by the associated low-to-mid level cyclone will begin to support heavy snow developing along the Sangre de Cristos Mountains beginning late Saturday, continuing into early Sunday. WPC PWPF indicates locally heavy storm total amounts exceeding 8 inches are likely there. Further to the north, enhanced convergence supported by a wave embedded along a low-to-mid level boundary will help generate some locally heavy totals along and east of the north-central Wyoming mountains, including the Big Horns. This boundary is expected to help focus organized snow with some potential for locally heavy amounts across portions of southeastern Wyoming and northeastern Colorado into the Nebraska Panhandle. ...Southern Plains to the Ozarks... Days 2-3... The previously noted southern stream trough is forecast to move east of the southern Rockies, with a closed 500 mb low developing over the southern High Plains on Sunday. Strong upper forcing will support snow spreading east of the Sangre de Cristo across northeastern New Mexico into the Oklahoma and northwestern Texas Panhandles Saturday night into early Sunday. WPC PWPF continues to show high probabilities (greater than 70 percent) for accumulations of 4 inches or more across this area. Meanwhile, as an upper center begins to close off, models show light to moderate precipitation developing in the associated comma-head further to the south across northwestern Texas and Oklahoma. The general model trend over the past 12 hours has been further south, lowering QPF and the probabilities for heavy snow across the northern Texas Panhandle and western Oklahoma. Marginal boundary layer temperatures are likely contributing to lower probabilities for heavy snow throughout the region. Moderate probabilities (greater than 40 percent) in the latest WPC PWPF are now confined to a small portion of the southern Texas Panhandle. Despite the low probabilities, cannot rule out the possibility for locally heavy amounts, especially where mesoscale banding supports heavy snowfall rates, overcoming the warm boundary layer temperatures. The upper low is forecast to track east across eastern Texas and Oklahoma late Sunday into early Monday, before reaching the lower Mississippi Valley later in the day. Models show marginal temperatures continuing to limit snowfall accumulations. While areas of accumulating snow can be expected, especially in the Ozark region, WPC PWPF for accumulations above 4 inches are less than 10 percent. Pereira