Vapor loop trends over the last few hours indicate increasing curvature along the limiting streamline/baroclinic zone in the southeast. The 12z NAM indicates strong warm air advection in the 850 and 700 mb levels over South Carolina and western North Carolina, while the broadening baroclinic leaf along the eastern seaboard will further intensify cyclogenesis with latent heat release. The shortwave trof located over western Nebraska/SD will tend to intensify and negatively tilt the 500 mb trough, ejecting the jet max over the MidAtlantic later on today, leading to deepening of the low in the Virginia - New Jersey region late tonight. Liquid equivalents of less than 1cm, while not appearing on the latest ETA progs, will provide more then enough moisture for a heavy snow event. HPC favors lighter precip this evening (expected accumulations of ~1.5 inches in VA) with decreasing amounts over the Cape Cod area the next day. In all, it appears the ETA solution will be the most accurate, as it displaces the surface low further east by f42. I would not count on significant accumulations in the NE, but 4-6 inches could be possible given the presence of increased forcing along the baroclinic zone and associated with the maximum in cyclonic vorticity advection currently passing through Southern Indiana and western Ohio.