Most models showing an inch or less from Perth Amboy to New Hope up to about 78 and <1/2" from 78 to 80 and basically no snow north of 80. Could be 1-2" from 276/195 in PA/NJ up to Perth Amboy to New Hope. South of 276/195, roughly, where the criterion for an advisory is 2" of snow in 12 hours, winter weather advisories are up for 1-3" of snow. Maps in the posts above have been updated and show a little less than they did this morning. A complete whiff is still possible for anyone north of 276/195 and the worst case is probably 2-3" north of there.
Temps overnight should be 30-31F in most locations, so any falling snow should accumulate on untreated surfaces. Would be very surprised if any schools are cancelled - at most a delay until 10 am, when any snow on any pavement anywhere in the region should be mostly melted by the indirect sunlight and temps climbing into the mid-30s.
http://www.weather.gov/phi/
Tonight's models have moved back to the NW just a tad, meaning the 1" line might now be 78 instead of New Hope to Perth Amboy, which is what I said earlier, and the 1/2" line would probably be at 80, with no snow north of 84. The 2" line would likely still be around 276/195. Splitting hairs here, though. Minor snowfall, could be slick between 2 am and 8 am for most folks south of 78 and especially closer to 195 and it'll be gone by early afternoon.