I think the subtle but significant orientation of the 250 mb jet is driving this bus. If you look at the Thurs run when models were showing a potential blizzard the jet on the west coast was more broad and less wind. This made cyclogenesis more likely on the East Coast. Now with today 6Z EPS run you can see the speed had greatly magnified in speed and orientation. This created a monster spin inside which forces any secondary inside the coast. The 50 50 low is booted, high pressure is overwhelmed and we are left with a soueaster