The 12z GFS depiction of a snow storm over the NC to VA makes sense to me. I take note when the GFS holds energy back, because its a model that likes to push things forward in the medium and long-range (I'm not sure if this bias has been corrected). This creates enough time for the upper level low to close off in the Southeast. EURO and GGEM has shown this solution.
Anyway plenty of cold air available to produce snowfall all the way to the coast. As has been the case for the last few weeks, plenty of tropical moisture available in the Atlantic. This moisture pocket, and associated warm air, just keeps sticking around, will allow for a larger temperature gradient to develop. We saw it with the Bomb storm, were seeing it today, and the models continue to push this tropical air mass towards the southeast. Even here in Hollywood, FL, we experienced this temperature gradient and the prevalent tropical moisture pushing back in from the Bahamas and Florida Straights (an area where pretty strong LPs and boundaries have formed within the last few weeks).
Meanwhile, there's plenty of entertainment weather-wise over the next two weeks, and plenty of interesting questions. We have crazy anomalies in Canada next Monday. 0c line pushes to the Arctic Ocean, and 2-meter temperatures in the NW Territory push into the 2-5. A couple more cold fronts. We'll see if it results in any snowy possibilities. Additionally, GFS and and a few other runs of other models seem to present the possibility of a subtropical system forming at various time frames. I can see it happening. But overall, the main question is how long can cold air keep plunging this far South? Eventually, these cold air masses are going to need to recharge. If positive anomalies continue to form over the North Pole, can these fronts continue to push extreme temperatures into Siberia, and consequently, the Eastern United States.
End of Verbal Vomit.