This is going to be a very complicated event, with two low pressure centers interacting from the Midwest and Southeast up through the northern Mid-Atlantic as the coastal low takes over for New England. Mixing will be a problem for North Carolina, southeastern Virginia and southern Delmarva, which could shift a bit north or south, depending on when, where and how quickly the coastal low can develop. A quicker low development off the East Coast would draw cooler air down from the north and create more snow over the “Mixing” area highlighted on the map.
Snow totals have been bumped up for West Virginia and Pennsylvania as the low pressure center over the Midwest will be stronger than originally anticipated, which will help squeeze out more moisture in the western and northern parts of the region. This stronger Midwestern low is also what caused the mixing issues in North Carolina to jump northward, as it will create a stronger southerly flow in that area and will draw warmer mid-level and low-level air northward before the coastal low gets cranking.
As the coastal low comes in stronger than expected, higher snowfall totals are possible in the New Jersey, NYC and Southern New England areas as it progresses northeastward. NJ/NYC/SNE could see another round of 12-18+ inches of snow from this storm.