There isn't enough model or sensible weather consensus to deal properly with the massive beast that is now turning into a full-blown blizzard in Denver - 10-18 inches now forecast and that might be conservative.
The reason for the increase is the same reason why the weekend here is becoming a tough call. The main upperlevel feature will go into Canada after burying the Great Plains and cut off. A secondary feature containing severe weather will begin to hammer the Southeast.
Will they phase into a superstorm for the East? The models now say no. But that will still leave a lot of bad weather that has to get through the Middle Atlantic. The question becomes when and how strong? It now appears a rain area will impact us Saturday afternoon and night, possibly carrying over into Sunday and Sunday night. But it looks more like a scattered-showers situation than a steady rain like we had Tuesday and yesterday morning. The devil will be in the details. But more will be known by this time tomorrow . . . or about five more model runs.
A complicating factor is that moisture from a tropical storm that was west of Hawaii 2 days ago is being entrained into the system that is currently colliding with cold air from northwest Canada. The reason I had 1.25 inches of rain at my house between midnight and 9 a.m. yesterday was the moisture added by the Category 5 hurricane that formed off Mexico last week, then hit near Manzanillo as a tropical storm.