ROOSTA

If you look up marginal airmass you'll find this in the dictonary.
Crash baby, crash!

If I were back in MA. I'd be going apesh*t. All this wasted QPF!
Look a dual- SFC LOW. The Ocean L is starting to explode, take over the circulation. 
Fear not the change-over will be swift, estimating change to be complete by 12z in the Metro BOS area, 13z in the SS and clear the S coast by 15z.
Should go to town tonight for several hours. Est. rates of 2-3"/hr. Smashed potatoes.
Accumulation maps are useless- all boils down to obs. and nowcast.   

Ok someone must be on a website that can post a 700 VV map at the height. Guaranteed that (pic) map in this case will tell a story.

Pilot to bombardier:
Give me a vector Victor and don't call me Shirley!
This is going to be fun watching it unfold. Target insight and it's going to be explosive bomb equipped with an eye and spiral banding.  
 

The actual 5H VORT on satellite WV seems to be slightly S and E of what the 12z models initialized. 
Getting close to real-time, nowcast analysis.  

The RAP does give the Dacks 4FEET!
Ya thats going to happen!!!

Things that are going to occur. 
I think the winds along the E coast will approach Storm Force

12z NAM

With that 12z HRRR you could overlay a Topo Map almost an exact match
Meanwhile I'm 80F with a Td of 72F. Stiff SW winds 20-30mph, with gusts Oh and a threat of Thunderstorms.
I've lost my emotional attachment.

Do not look at 12z HRRR.
There are some 3' amounts in them their Hills of W Ma.
A thing of beauty!
Two feet or Bust!

The BUST potential +/- is larger than any storm as far back as I can remember.
Two areas in particular:
Ctrl NYS forecast 2' could bust by 2'
SE Ma. CC forecast 2" could bust by 2'
Today's War Cry "2' or BUST" All together now... 

QPF lost about 2" across the board.
Dumfounded!

Drew Barrymore: "Back-off, back-off.
FIRESTARTER
There is something wrong with models. Houston We Have A Problem. Each model has a bias and well known but this is ridiculous. Over programmed and overloaded with unseen data?
No way to explain...

To be honest I really hate SF maps from the assorted models. It's not representative of the pending changes in model runs.
Now a personally drawn map is an individual forecast inclusive of start to finish.
With that said my weenie side results in a possible outcome to this chaos...
SUBJECT TO CHANGE  

Stated days ago, that ORH S and E would get burnt. Probably way off but it's only fun at least for yours truly.  

The more you start TOSSING you'll end-up with nothing.
One of these models is (will be) less wrong then another.
Million-dollar question, which one?  

Some clarity... ummm, back to uh oh ummm...
Fog incoming down to vis < 1/8 mile.
Ah, just stick with elevation. Cut back amounts. "Everything gonna be alright."  

GOOD
AWFUL
WTF Which is it? Anyone care to elaborate?

2 minutes ago, 78Blizzard said:

It's 2 days.

I'll compromise (2 1/2) it's just a comment to express a point not exact time, Geez!
Anyways from beginning to end, end being sometime Wed. Total accum by 8am.  

NWS watch, warnings from BOX are measured in content, seem accurate with wiggle room to upgrade or stay as is for 3D lead-time.  

9 minutes ago, 78Blizzard said:

LOL. Half the forum is praying for the Canadian solutions, and half for the GFS and NAM.

It's all tied to IMBY. The scientific aspect is lost come threat time, wishing doesn't equate to an accurate analysis unfortunately. Weigh the comments by who posts.  

TIME: Getting close to <48hrs to go time. Sort of running out of model runs. Huge EU run, liking the trends to an offshore more impactful event for Eastern area's. Goalposts have narrowed enough to either your in or your out. Boiling down to the haves and have nots and where?   

SREF's (admittedly out-of-range) have a MEAN accum across the landscape much lower than the clown show.

2 minutes ago, EastonSN+ said:

It would be cool if they developed an interactive tool where you can plus in any ratio and the algorithm would spit out the map.

Software available via Unidata. AWIPS and it probably is used by the NWS. I know with GRADS it's just a simple script change in programming, 

oh-oh,
Mets are playing conservative and for good reason IMHO. The BM track is becoming less likely. Not a perfect capture, stall and stack. Indications leaning toward by the time it does consolidate the SFC center will be at the LAT of BOS, the moisture will have been displaced to the E. so even if the BL cools to support snow it will be of no consequence, also the 40-60mph. gusts from the E toasting the coastal plain. W New England Ctrl NYS parts of the Berks will cash-in on the UL dynamics.
Put your horses back in the stalls. This is far from resolved and can change on 6hr intervals.    

No dog in the fight really changes the emotional attachment. 
If you had money on presenting a forecast, I think many would start very conservative most probably wouldn't even comment or forecast. 

Many are getting out over their ski's re: The BOX snowfall map?
As mentioned, the Agency is where the public turns for Official information and responsible for numerous other Agencies, i.e.  Public Works, EMA including the safety of the General Public. It's a First Call Map and way out of range.
I'm probably one of few who think it's prudent ATT.