Very Complicated...
Barry talked about the many packets of energy swirling around an upper level vortex in his blog posting from earlier today...it really is incredible how complex the atmospheric set-up is. Each one of these pieces of energy capable of flaring up a new convective band or enhancing the one that is already established tonight over Connecticut...or even spinning up a new surface low altogether! For the models to digest all of these features and place them in the correct location with the correct intensity at the correct time is virtually impossible. With that said, we have the Norlun placed in the correct spot for formation...thankfully...in SW CT up into the Hudson Valley...now the key is figuring out when it will move north and east and how intense it will be when it gets here.
The Norlun is literally creeping thru CT and at the moment is essentially stationary. This stagnant movement is pummeling parts of Central and Western CT...already over a foot in some towns: Bridgewater 18", Danbury 13", New Milford 13", Brookfield 12"...at the same time Eastern CT has had only flurries...classic Norlun! Most available model guidance shows this band and its associated upper level energy migrating north and east into Mass overnight tonight. So that when it does finally get to us it should be in a weakened state snow totals won't even come close to what they are getting down there (they better not)...in fact between the ocean effect and the mesoscale band we are likely looking at only a couple of inches through tomorrow morning. After that the band should fall apart and with lingering flurries during the afternoon. Regardless of how much snow falls tomorrow during the day I think it will have a tough time accumulating due to milder temps...low to mid 30s.
The story doesn't end in fact it gets a little more complicated as some of the models over the last few days have been hinting at something Saturday night they are now almost all finally latching on to surface low pressure development, and so are we, SE of Nantucket. This will successfully spread snow back into parts of Southern New England tomorrow night likely leaving behind 3-6" in SE Mass with 1-3" in the Boston Metro area and very little if any north and west of the city. All snow and snow threats will finally be gone by Sunday and we get a couple of tranquil days before we have to get back on the saddle middle of next week.
I hope this all plays out the way we are currently thinking...we are dealing with convective bands here so the likelihood of this forecast verifying isn't as high as I'd like but that is my best stab at it. For now, I'm going to enjoy the unfolding of this Norlun trough event and be thankful that it didn't develop over us...what a bear...