On the point soundings for SE MA, it had a good cross-hair sig on the 12z run....your area may have been a little far NW on GFS for the real goods in that department, but it wouldn't take much of a move to get into them.
Seems like that trailing s/w being stronger in the 1/7 event plus it's trying to phase a bit with that northern piece traversing the N stream is locking in the confluence better for 1/10 on some of these runs.
Leading wave does look stronger through 54h on the 12z run vs 06z....the trailing wave is also closer....might try and get a quasi-capture on this run like the Euro? We'll see.
For American models (GFS and NAM), I still think PSU is one of the best combos of decent graphics and fast updates. Faster than TT usually on those two models.
http://www.meteo.psu.edu/ewall/ewall.html
It isn't because the storm usually consolidates onto one shortwave/vortmax. But this is the type of situation where it could not do that if that front runner gets sheared quick enough....my personal gut feeling is that the front runner survives enough for a decent event from that piece of energy with maybe a little lingering -SN from the trailer. But prob not one of these 30-36 hour deals.
That's kind of what the 06z GFS did....maybe weakened the first s/w slightly too miuch for your description, but it basically turned the event into a 30-36 hour light snow with maybe some moderate bursts for eastern areas Sunday PM as it tries to re-invigorate from the trailer shortwave before it exits.
NAM would actually have the storm on the kicker wave....the front runner gets ground up so much that it isn't able to sweep away the baroclinic zone with it.
06z EPS maybe looks like it has a better cluster NW than 00z? Not sure what mean QPF looks like yet, but the SLP looks slightly better. No huge changes though.