Tonight’s NAM has the freezing rain/sleet starting a bit later, into the evening, closer to 6 pm Monday for PHL, earlier to our west.
Still a borderline rain/sleet changing to snow event with very little, if any, accumulation. Icy conditions is the main issue.
Monday 4 PM: The precipitation started earlier than I had forecast last night. Fallling as freezing rain with difficult driving conditions.
A small disturbance moving in from the northwest will join with the return of some upper air warmer flow from the south to give us the chance of light snow (less than an inch) around the evening rush hour Monday.
QPF values are only 0.07 inches water. It had appeared to be a possibility of sleet or freezing rain, but right now, it appears it will be snow in PHL north and west. Slippery driving is likely.
6 PM Update: This afternoon’s models show the upper atmosphere too warm for snow in PHL tomorrow afternoon. So it appears that the small amount of precipitation will fall as sleet and freezing rain. Still an icy situation.