Heavy snow is expected across the northernmost parts of the forecast region, with lesser amounts the further south you go as snow at the onset of the storm battles with warming mid-levels as the storm pushes through the Mid-Atlantic. Timing of the changeover to sleet/freezing rain/rain will be critical from central PA roughly from I-80 (or even a little north of that) southward… so yeah, that’s a large area to watch for the changeover. After the storm passes, some residual moisture playing the upslope on the west side of the Appalachians could bring 1-2 inches of snow into the higher elevations of WV and the WV/MD panhandles.
Significant (damaging) icing is possible in southern OH, southern PA, WV, VA, western MD and western NJ, which is not shown on the map. For the DC area, places around I-95 and points east should have little to no icing, but west of I-95 up to 0.25-0.5 inches of ice is possible. Further north into PA/NJ, more notable ice is possible east of I-95. My forecast map includes snow+sleet accumulation, but not ice from freezing rain.
NEW! I added a confidence bar to my map, with a scale of 1 (low) to 5 (high). I almost always write out my forecast confidence in these blog posts, but those who just look at the forecast image will miss it, so I figured I would fill in some of the negative space with some useful information. The confidence in this forecast is 2 out of 5 (low-medium).
Here is the latest ice accumulation forecast from the NWS for the LWX forecast region: