Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 327 AM EDT Tue Mar 15 2022 Valid 12Z Tue Mar 15 2022 - 12Z Fri Mar 18 2022 ...Interior Northeast... Days 1... Minor troughing over the Great Lakes and Northeast with a few embedded impulses will move through. A stationary boundary draped through the area combined with the mid/upper level forcing for ascent will bring a narrow frontogenetical band of light snow to the interior Northeast toward central Maine through this evening. Accumulations will generally be light with some slight to moderate probabilities for 2-4" over the NY Adirondacks and Presidential Range in NH. ...Pacific Northwest through the Rockies... Days 1-3... Plume of Pacific moisture streams onshore across the Northwest today/tonight associated with a longwave trough will bring widespread precipitation to the region. Snow levels mostly above 5000-7000 ft will confine the greatest snow accumulations to the peaks of the Olympics and WA Cascades. As the moisture spreads inland, heavier snow reaches the northern Rockies. WPC probabilities are high for 6" or more for the WA Cascades and reach moderate levels for ID and northwest MT. A reinforcing trough digs over the Great Basin Wednesday resulting in lee cyclogenesis over the southern High Plains. Meanwhile, strong high pressure nosing south from the northern Plains will result in a tight pressure gradient favoring upslope flow over the Front Range. Temperatures are marginally supportive for wet snow, greatest in the higher terrain region. The latest WPC probabilities for 6 inches or more are 50 to 80 percent where some isolated double digit totals are possible. A reinforcing trough digs over the southern Great Basin Wednesday setting up lee cyclogenesis over the southern High Plains to combine with high pressure shifting down the northern Rockies Wednesday night to bring precip in a marginally cold profile to CO Wednesday night, shifting into northeast NM Thursday. For Days 1-3, the probability for receiving at least 0.1" of freezing rain is less than 10 percent across the lower 48. Taylor