As I mentioned last night, the NAM model showed a  westward extent of the snow for Saturday from the coastal low.

Today’s NAM has continued with that trend, with a rapid decrease in QPF values west and north of PHL.   Areas in New Jersey will have significantly more snow.

Currently, the QPF for Philadelphia Airport is 0.25 inches water which translates into 3 inches of snow.  Areas such as Blue Bell, have a lower QPF, closer to 0.18 inches water.

The GFS has joined in with that westward extent of the precipitation shield.

The NAM data for tonight’s run becomes available about 9:40 PM and I’ll update after that time.

Additional info: the snow coverage and amounts with Saturday’s storm is unusually low confidence, especially here in Philadelphia.  Slight differences in the low pressure’s intensification or track will greatly affect the snowfall amounts.

The low pressure system that gave us the light snow is out of here.

Attention turns to a second low pressure system expected to develop along the arctic front and move up on Saturday.   The GFS still keeps the storm to our east, only affecting the eastern parts of NJ, while the NAM continues to show it slightly west, giving us another light snowfalll here in PHL.   (1-2 inches on Saturday morning.)

The statistical models maintain the track offshore and the NAM is a bit of an outlier here, but this still needs to be watched.