Probabilistic Heavy Snow and Icing Discussion NWS Weather Prediction Center College Park MD 404 AM EST Mon Feb 08 2021 Valid 12Z Mon Feb 08 2021 - 12Z Thu Feb 11 2021 ...Significant Freezing Rain Potential Develops through Midweek over the Mid-Mississippi and Ohio Valleys... ...Great Lakes and Ohio Valley to the Northeast... Days 1-2... A fast-moving shortwave trough crosses the northern Great Lakes early Tuesday with surface low development off southeast New England late Tuesday. Warm air advective precip develops tonight across the northern Mid-Atlantic, with local enhancement perhaps allowing moderate snow in areas such as the Poconos which have an upslope component in southerly flow. More widespread moderate snow is then on tap for later Tuesday across southern/central New England. Day 1.5 snow probabilities are 20 to 30 percent for 4 or more inches from northeast PA, southern NY, and the Berkshires/southern Greens of VT, expanding across central New England to the Maine coast. ...Ozarks across the Mid-Mississippi Valley up the Ohio Valley across Central Appalachians into the Mid-Atlantic... Days 1-3... Deep and sprawling low pressure, centered over northern Ontario through midweek maintains particularly cold air over the north-central CONUS with a baroclinic zone slowly developing tonight from the southern Plains to the Mid-MS Valley with a wave passage, then is reinforced Wednesday into Thursday as the next trough axis shifts east from the Desert SW allowing enhanced Pacific moisture to flow toward this baroclinic zone that expands east along the OH River to the central Appalachians and central Mid-Atlantic. By early Wednesday, right entrance upper jet forcing along with the aforementioned low-level boundary is expected to support the development of better organized precipitation from the Mid-MS through the OH valleys. Shallow arctic air in place will likely support a wintry mix, with the 00Z guidance continuing to depict a narrow area of overrunning and increased confidence in significant ice accumulations from southern Missouri and northern Arkansas eastward along the main stem of the Ohio River beginning late Tuesday and continuing through midweek. By Day 3 there are moderate probabilities for a quarter inch of ice or more in 24hrs along this stripe from southeast MO to western WV. Should guidance continue to depict a similar swath in a similar location, watches may be warranted by this afternoon. A stripe of snow is expected north of the freezing rain, with central IL/IN/OH, northern WV to the Potomac Highlands, southwest and south-central PA and north-central MD with low to moderate probabilities for 2 or more inches of snow. , Indiana, Ohio and central Appalachians likely to see at least a few inches of snow Tuesday night and Wednesday. ...Central Rockies... Day 2... The trough shifting east to the Desert SW Tuesday night allows Pacific moisture to converge on western CO ranges in proximity of a stationary front. This allows for locally heavy mountain snows with Day 2 snow probabilities for 6 or more inches moderately high for northwestern CO ranges. Jackson