Tonight’s NAM model data has become available.  Here are the trends– the NAM has reverted back to its forecast from a day ago. The storm is a bit less developed and a bit faster.  Total QPF values about 0.70 inches water with the heaviest snow ending about 8-9 AM Thursday.

Based on temperature profiles, the precipitation starts as rain or rain mixed with snow about midnight Wednesday and changes to snow sometime between 3-4 AM, then continues as snow until 8-9 AM.  Warm surface temperature before the storm will reduce snowfall accumulations. Best guess is about 4 inches in the immediate PHL area, up to 6-8 inches north and west, less in southern NJ.

This afternoon’s GFS had much higher QPF values and greater intensification of the storm. ( Tonight’s GFS model data won’t be available until later tonight.)

Will update tomorrow morning, but we won’t really have a handle on this storm until Wednesday evening’s model runs.

A quick 11 pm  update- the latest GFS is similar to the NAM – QPF similar (0.89)  and ending earlier  about 7-8 AM