Since I have the time tonight, I'll do a live thread with the 0Z models, posting them as they come out. Keep in mind they all ingest the same starting data (as far as I know), but how they assimilate that data and how the models perform the numerical analyses and the physical chemical parameters used and the resolution/grid-spacing used to generate outputs like snowfall maps and atmospheric conditions in the future are all different from each other.
And some are longer range and global (Euro, UK, CMC, GFS and more), while others are shorter range and mesoscale (not global, with higher resolution for estimating things like convection, like the NAM, RGEM and HRRR); in addition, they all have some strengths and weaknesses. The NAM/RGEM (non-global) comes out by 10 pm, then the GFS by 11 pm, then the CMC/UK by 11:30-12:00, then the Euro by 1 am - the time it takes is a function of how complex they are plus if they're global or not (more calcs). Also, keep in mind that the storm hammering the west coast is now fully on shore, so it should be fully sampled, which ought to lead to better, more robust output.
Anyway, as someone already posted, the 0Z NAM is snowmageddon for the entire area, so I posted the usual graphic from Pivotal, plus a close-up screen shot. The NAM is a mesoscale, short range model, known for sometimes overamping, i.e., occasionally showing more precip than other models.
And the RGEM (a Canadian mesoscale, short range model, also called the RDPS) is also snowmageddon. Holy crap.
And now here's the first of the global models, the US's GFS model. Not quite snowmageddon, but still a pretty big hit, and a little snowier than it was at 12Z this afternoon, i.e., a small hange. The GFS's cousin, the GFS-V16 (new and improved GFS, supposedly, which has been plagued with rollout issues), looks pretty similar.
The snow keeps coming. Here's the 0Z CMC (also called the GPDS), the Canadian global model. This one is certainly in the snowmageddon camp for most.
Well, there's always a party pooper and tonight it's the UK (again), showing a lot less precip for everyone and shifting the snow shield SE from where it was at 12Z (back to where it was at 0Z last night - it's usually a good model, but it has been a bit erratic lately). Certainly an outlier tonight, so far, assuming the Euro continues to show a major storm in about an hour.
And the 0Z Euro is a bomb, like 18Z was, both of which are far snowier and with snow much further NW of 95 vs. today's 12Z run (in the quoted post above).
So, it was a big night meteorologically speaking. The bottom line is we have moved from the potential for a significant (4-8") to major (8-12") snowstorm, yesterday, to a fairly high likelihood of having at least a major snowstorm with the potential for a historic snowstorm (12-20") for much of the Philly-NJ-NYC region. I would expect the NWS-Philly to extend their winter storm watches (now just for areas south of 276/195 and Middlesex) to their entire set of counties and for the NWS-NYC to issue them for their whole region (which includes Union-Essex-Hudson-Passaic-Bergen in NJ) and I'd expect the NWS to significantly increase their snowfall forecasts from 3-6"/6-10" now to more like 8-12" for most of the area and perhaps even 12-18" for the 95 corridor, although having been too aggressive recently on 12/16, they might just stick with 8-12" for now and only go up further if we see a similar set of runs tomorrow (the NWS swaths go from 8-12" to 12-18" - if they had a 10-15" swath, I'd use that).
We're still 48-54 hours from the start of the storm, so things can still change, even substantially, but that's getting less likely as we're getting pretty close to the event, although as I said last night, we've seen a few major busts occur as late as 6 hours before a storm starts (but those are very unusual). But even if a major bust doesn't happen, seeing a 25-50 mile shift in the entire snow shield is not a huge movement inside 48 hours, i.e., the heaviest snow axis could easily move from the 95 corridor to 25-50 miles in either direction still, meaning a lot more snow NW and a lot more rain along the coast and towards 95 if the move is NW or it could mean very little snow NW of 95 with the heaviest snows SE of the 95 corridor if the move is SE. Either of those outcomes would be a pretty big bust for some, but not all.