Well, the NWS went partway to what I thought they might, issuing advisories for the rest of SNJ and watches for all of NYC, but surprisingly, no advisories for Mercer/Middlesex or NE NJ (Union up to Bergen), even though the maps show 2-4" of snow.
And since these were issued, the 6Z NAM (both the 3 km and 12 km NAMs) came out showing 12-20" of snow from 95 eastward and 6-12" within 20-30 miles west of 95 and the hi-res HRDPS (kind of like the 3 km NAM, a high res model0 shows 6-12" from 95 east and 3-6" west of 95, but the 6Z GFS and RGEM only show maybe 2-4" for I-95 and a bit more for the coast. Very hard to make forecasts with model runs like that. Maybe the NAM is just a hiccup or maybe it's on to something. I have no clue. Anyway, here's the map of watches/advisories warnings and snowfall maps are below that. Gotta work today, so not many posts expected unless the 12Z runs look like the NAM.
Quick update - everything is trending snowier in the models. I could leave it at that with some maps, but I can't, lol.
As expected, NWS upgraded the next tier of counties (SW NJ, Philly area in SE PA and Mercer/Middlesex to advisories for 2-4" and I imagine these will be warnings by 4 pm, given continuing snowier model trends with today's 12Z (7 am EST initialization) model runs, especially amongst all of the global models (Euro/UK/GFS). In addition, the actual storm and the players are verifying what the very snowy mesoscale models were saying last night, not what the less snowy globals were saying, which means the globals are likely playing "catch-up" which is why they've moved towards the mesoscale models snowier outputs.
The globals generally went from a 1-3" Philly-NYC event to a 3-6"/4-8" event, while the mesoscale models are showing more like a 6-12" for I-95 or more. And all of the models are showing 25-50% more for the coast and LI vs. Philly to NYC, i.e., 6-12" snowfall, at least is looking very likely for those locations. And, of course, the models are showing maybe 25-50% less for locations 20-50 miles NW of 95, roughly. NWS also upgraded the coastal counties to warnings for 4-8" of snow. Snowfall maps were also updated. Finally, keep in mind that these totals will likely all need to be multiplied by a factor of about 1.5 considering likely~1.5:1 ratios of snow to liquid equivalent precip, i.e., a 4-8" snow would be 6-12" in depth (same mass), since the snowfall maps all assume a 10:1 ratio.
The big question now is whether the global models will continue to move towards the big snowstorm ideas of the NAM and other mesoscale models or not. Jury is out on that, but it's looking very likely that we're at least getting a moderate to significant snowfall starting in the wee hours tomorrow and continuing into the afternoon. A miss is almost out of the question, but after Jan-15, it's hard to say that this couldn't still be a lot less snow. Similarly, a 12"+ snowstorm for almost everyone is on the table, as are blizzard conditions for the coastal areas of NJ/LI, as well as moderate tidal flooding with winds possibly gusting to 40-50 mph near the coast and 30+ mph inland.
Finally, this will all be followed by brutal, record-breaking cold for Friday-Sunday, with wind chills becoming dangerous for Friday, at least. Will post something more on that later.