The latest NAM data has become available. The QPF is more in line with the  GFS data from earlier today. The latest QPF is 0.46 inches water for PHL, increasing  considerably eastward into NJ to almost 0.90 at the coast.

For Philadelphia,  that QPF translates into 5-7 inches of snow.  The NAM has the onset in the early morning hours before daybreak, with the heaviest snow during the morning, ending about 2pm. Areas in NJ may have snow totals in excess of a foot of snow.

The early GFS data becomes available 10:30 pm and I’ll update again after that time. (The GFS values are often lower.)

Reviewing additional NAM data, the snow may be minimal before 7 am with heavy snowfall after daybreak .

Some of the higher resolution models have lower QPF values, in the order of 0.30.

Waiting for tonight’s GFS data, but 5 inches is the most likely amount for the immediate PHL area based on averaging the data.