I’ve had a chance to look at the models from earlier today  and the NAM is just becoming available .   There are large differences between the GFS and NAM regarding QPF with the NAM warmer and wetter than the GFS by a large factor of 2!  I prefer the NAM in general for temperatures, but it does tend to overstate QPF

There are two storms conveniently on two days, so let’s talk about Tuesday.  The critical temperatures specifically in the mid levels of the atmosphere are too warm to support snow in Tuesday in the immediate PHL area.  Dynamic cooling may chill things down for some sleet, and snow but I’m thinking mostly rain with little actual accumulation for Tuesday.  The rain may be heavy.

The Wednesday storm is looking much colder and temperatures in the mid levels drop low enough to support snow.  With high QPF values, there should be enough chill for accumulation.  4-7 inches is possible on grassy surfaces, less on roadways if the QPF values remain high. The GFS was much lower on QPF and it would be more like 2-3 inches.  It’s too soon to determine QPF and accumulation for Wednesday, especially with such a complex system.  Will have to wait until tomorrow evening.