1) High is holding on more strongly than first thought. This will keep the lower levels colder as cold air gets locked in east of the mountains.
2) Winds along the coast of NJ-DE-MD-VA are from the Northeast and north. This signals that the lower level cold air will be tough to scour out, and storm will track a little more offshore as the coastal front sets up just off shore.
These two factors are included in my forecast:
Tonight through Tuesday 7 pm: Light snow develops, then changes to freezing rain very late or toward morning. Off and on light rain will continue through the day, before changing over to wet snow by 7 pm. Winds will become quite strong out of the north. Temps near 33 during the day.
Tuesday Night 7pm - Wednesday 7 am: Wet snow of varying intensity. There is the potential for some very heavy bursts of snow, that will add up quickly. However, this is not certain at this time. But be prepared if it does. Snow will continue off and on for the day on Wed with additional accumulation possible. Very windy and cold with strong winds out of the north and northwest. Temps near 32 at night and 34 during day.
Accumulations will be very elevation dependent. (If you live on a hillside, scale your accumulations to fit you elevation):
- Valleys: 2-3 inches by Wed 7 am.
- Ridges/Mountains: 4-6 inches by Wed 7 am.
- If the heavier snow bursts develop (which closed upper lows commonly do produce them) then take the accumulations and double them.