For Sunday evening– Low pressure will develop in the middle of the country and move eastward as it intensifies over PA and NJ Sunday evening through Monday morning. Snow will overspread our area Sunday evening and become heavy after midnight and during the predawn hours of Monday.
Warm air is expected to move in at about 5000 feet in and around PHL, so a changeover to sleet and possibly freezing rain will likely occur towards daybreak Monday morning. A change back to snow will likely occur before ending early Monday afternoon.
Uncertainty about the northward track of the low and the amount of warm air mixing in will make accumulation prediction very difficult around PHL, but areas to the far north and west may have snow amounts around 12+ inches.
Unlike the ‘blizzard’ that wasn’t, this storm will more likely be impactful with accumulations of 6 or more inches possible (but not definite) around PHL by Monday morning.
I suspect the NWS is being overly cautious about over-predicting this one. I don’t think this one will fizzle out. Stay tuned.