Sun angle and rates will be a factor, yes... but with the crashing temps in the wake of the front I still don't think it'll be that much of an issue. I've seen 6" of snow in April a few years ago. With the heavier rates and plummeting temps forecasted, I think roads will be covered and colder/grassier surfaces will still see a decent accumulation. Those of us in Berks and the Lehigh Valley should expect 4-6" of snow, with probably 3-4" on roads and pavement if the rates do come in heavy.
Also, don't forget about the winds behind and during this system. Should see some decent gusts and sporadic tree damage/power outages.