The trough associated with the storm system last week is now trapped along the east coast between ridging over the Midwest and the northwest Atlantic. As the trough sharpens, intense vorticity will slam against the ridge over the Atlantic, tilting the trough negative and cutting off as an upper low. This low will lift northward toward southern New England, with surface cyclogenesis over the western Atlantic. The surface disturbance will strengthen quickly with the upper level support and get pulled west toward the region.
With the upper low cut off from the mean flow, we won't have a source of cold air to the north, however we will benefit significantly from dynamic cooling as the low moves over head. Model guidance has trended west, placing the low near Boston by noon Monday. So this could be a situation where northern New England experiences rain showers while parts of central Massachusetts and southern New Hampshire are seeing moderate snow!
Based on the latest model trends, the potential does exist for some accumulation over the specified areas, including Keene, Monday morning. Certainly something to keep an eye on.