from NWS this morning:
The other tricky aspects of the fcst include: relatively warm
boundary layer/road temps, precip rates/banding, onset timing,
elevation, and wet bulb effects. Without going to far into the
weeds, the key takeaway for this cycle is that odds have
increased on the margin for accumulating wet snowfall across
south central and particularly southeast PA Sunday afternoon
into Sunday night. The largest % chance increase is for areas
to the east of I-81 with WPC, RRFS, and NBM showing low to
moderate chances (30-50%) of snowfall totals >1 inch. The
official NDFD fcst initialized off of the 14/01Z NBM is likely a
bit too low at this point and would anticipate/front-run an
uptick in POPs and snow amounts to be more in the C-1" range
with the next cycle. There is the potential for additional
changes to this forecast in the next 12-24 hours so continue to
monitor especially for possible early Monday morning commute
impacts.