Good summary and I think this one is definitely a case of details that will not be ironed out until we are on the inside track of the event. The big picture is conducive to a broad snowfall event, but the 700 mb warm layer along the south shore and Cape appears to be the critical swing element, particularly with the warmer NAM/GFS solution versus the colder high-resolution models. A quick punch-out of the initial heavy dose of precipitation could quickly alter totals and this should become apparent through radar imagery and surface observations rather than model output. Snow growth and intensity will also be important, as heavy lift in the dendritic growth zone may help compensate for marginal temperatures for a short period of time. This is definitely a storm situation where real-time impacts, such as snowfall impacts on road access around Boston Logan and Boston Logan car service routes may provide early hints at accumulation efficiency. How much confidence do you have in the colder solutions at this point remaining in place along the south shore once the event is underway?
