After weeks of mild and or quiet times, the atmosphere is reconfiguring into a favorable one for cold and snow. We've been eyeing this weekend as our first opportunity to receive a bona fide snowstorm. A stalled frontal boundary off the East Coast will provide a breeding ground for storms over the next several days. Storms that form here blow up fast because of the large temperature difference between the colder continental air and the warm Gulf Stream.
Late Saturday, a low pressure center will do just that. It will pass pretty far offshore Saturday night and Sunday keeping the deep moisture out over the ocean. The wrinkle is an incoming piece of energy called a shortwave.
This energy will tilt back to the west allowing for moisture along the western flank of the storm to get sucked back into New England. Getting accumulating snow hinges on this shortwave and models seem to have a better handle on it's interaction with the offshore storm now. Therefore, the probability for snow Saturday night is becoming more likely.
I won't throw numbers on a map just yet because I'd like to see my hunch get locked in today. But it is looking more like our first widespread plowable snow event. Maybe something like 1-3" with 3-6" Downeast?