Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 408 PM EST Mon Jan 27 2020 Valid 00Z Tue Jan 28 2020 - 00Z Fri Jan 31 2020 ...Pacific Northwest to the Northern Rockies... Days 1-3... An upper low and its associated frontal system will continue to weaken as it begins to move inland, but is expected to bring another round of heavy mountain snows as it moves across the region Monday night and Tuesday. Heaviest amounts are expected to fall along the Cascades, where WPC PWPF is showing high probabilities for accumulations of a foot or more across the higher terrain during the Day 1 period. Locally heavy accumulations are also possible for the Olympics, Blue Mountains as well as the western-central Idaho mountains. This system is expected to quickly move east of the region by Wednesday. However, an upstream ridge will quickly give way to onshore flow promoting additional mountain snows, with heavy accumulations possible especially along the high elevations of the northern Cascades by late Wednesday into Thursday. ...Southern and Central Plains... Day1... Models continue to show a compact shortwave and associated surface low dropping southeast from the central High Plains across the Texas Panhandle into the Red River region Monday evening into Tuesday. Cold air surging south on the backside of the system will support a change from rain to snow from eastern Colorado into western Nebraska and Kansas, the Panhandle region and Northwest Oklahoma. Models continue to present a signal for locally heavy amounts, on the order of several inches centered over southwestern Kansas and northwestern Oklahoma. However, confidence in the details remains limited in part due to uncertainties stemming from marginal boundary layer conditions as well as the changeover timing and duration of snowfall. Latest WPC PWPF shows greater than 50 percent probabilities for accumulations of 4-inches or more over portions of southwestern Kansas into northwestern Oklahoma, including the eastern Panhandle. The probability of 0.25 inches of freezing rain is less than 10 percent Days 1-3. Pereira