I think that the heavy precip & storm track will be guided by the dew point boundary.
Dews in the northern half of PA are in the 20s, while southern PA has dews in the low 40s currently.
March of 2014 had 3 storms that were modeled to hit Northern PA 2 days out, then bullseyed us the day before, then ended up hitting MD & DC while we whiffed on game day.