A little better from OKX:
A srn stream low pressure system moving across the lower Mississippi Valley Tue night will weaken W of the Appalachians on Wed while a secondary low takes shape near Hatteras. This system will have plenty of Gulf and eventually Atlantic moisture to work with, as well as a continued supply of low level cold air from the strong high to the northeast, so as this system approaches, expect snow to develop Wed afternoon, and then become moderate to heavy at times Wed night as the low wraps up just off the Mid Atlantic coast. Forecast mentions almost all snow at this point with a good chance of significant accumulation, with the caveat that the high to the NE may be modeled too strong, and if it does retreat more quickly that could allow for a more N/W low track, as well as potential for mixed precip for the NYC metro area and Long Island as marine air and possibly warmer air aloft get involved.