I think GYX gives a good explanation, saying that earlier development of low pressure over towards the gulf of Maine will interrupt the east southeast inflow and keep the temps from totally furnacing. That doesn’t stop the warming aloft though but might be slow enough to get an extra hour or two of heavy snow but if it lightens that it immediately mixes or turns over. They say that an extra two hours come in an extra four or 5 inches for certain locations which makes sense to me the gradient between five or 6 inches and 11 or 12 inches is almost over my head