Summary: a major winter storm is on our doorstep, but there are still model disagreements on the exact track and precip/snow amounts, so we need to keep an eye on future model runs and soon the radar and the evolution of the systems involved. The storm starts as rain for everyone in the late evening, but quickly turns to snow in NW areas and takes several hours to change over down towards 95 and the coast; for most of CNJ the snow will fall heavily from about 5 am through about noon. Basically, snowfall amounts of >8" are predicted along and N of 78 (with up to 12-14" N of 80) and most sources agree on that. South of 78 there is much more disagreement. I believe TWC map below, is more likely to be correct than the NWS map. TWC map is more bullish on getting 5-8" from 276/195 up to 78 and even 2-5" down to Philly over to Toms River up to 276/195, while the NWS is predicting more like 2-5" from 276/195 up to 78 and then only 1-2" along the Delaware SW of Trenton to Philly with very little S of 195 in NJ.
Details: So, given the significantly lower snowfall amounts on the Euro and UK (two very good models) vs. the generally greater snowfall amounts for most of the other models, the question is do forecasters do some kind of compromise or go with one camp or another or something else, as they have tools/knowledge most don't. Tough call, especially with the 18Z HRRR showing a huge snowstorm (10-16") for the entire area all the way down to Wilmington to LBI, but less for far NWNJ, as it shifted south maybe 50 miles, and the 18Z NAM also shifting things south a ways and with less precip (8-11" for most of the state, while the 18Z RGEM had 6-10" for everywhere N of 276/195. So there was some movement south but not by all of them and precip amounts weren't as low as on the Euro/UK so who knows? The 18Z models at least make it clear that there likely won't be some huge shift south as some had discussed
Anyway, as expected, the NWS-Philly did increase snowfall amounts south of 78, but not as much as I thought they should and they now have warnings up for Poconos/Sussex for 8-13" of snow, for the Lehigh Valley, Morris, Warren for 7-10" of snow and for Berks, NW Bucks, Hunterdon and Somerset for 4-7" of snow and they have advisories up for Middlesex, Mercer, Lower Bucks and Montco for 3-5" of snow and for Western Monmouth and Chester for 2-4" of snow. IMO, all of those places under advisories should be under warnings for 4-7" of snow, especially given the southward shift we've seen from some of the models which brings more snow further south, which would also likely decrease snowfall amounts by a coupe of inches N of 80. In addition, given that about half the models have 3-6" or more of snow for Philly and SNJ (even at lower ratios), I would expect those areas to at least be under advisories for 2-4" of snow.
Also, the NWS-NYC now has warnings up for Union/Essex/Hudson and NYC/LI for 4-8", warnings up for LI for 5-10", warnings for eastern Passaic, eastern Bergen and Western Essex for 7-10" of snow and warnings for W. Passaic, W. Bergen and the Hudson Valley north of the Bronx for 9-13" of snow (and for CT for 7-12"). It's certainly going to be fun to see this all evolve and for the rain then snow to finally come late tonight with possibly hellacious snowfall rates of 1-2" per hour from 4 am to noon with a quick shut off after that. I still think TWC map is better than the one from the NWS, but we'll see soon.
Tomorrow morning's rush hour has the potential to be extremely difficult from at least 276/195 up through 84 for all of EPA/CNJ/NNJ/NYC/LI/SENY/CT with very heavy snow falling with 8-12" or more along and N of 78 and very possibly up to 8" down to 276/195 which would mean over 1" per hour rates for the 8-9 hours of the snow falling - and even for areas with warmer temps and less accumulation on roads, visibility will be very hindered and roads in some places could become difficult to travel on, especially near/N of 78 and as I've said before where we see >1" per hour rates even at 33-34F, untreated roads will become snow covered as those rates will exceed melting rates.
Lastly, don't forget that minor to moderate coastal flooding is likely for DE/NJ/NY coasts on Tuesday and 40-45 mph winds are likely for coastal areas and 30-35 mph inland as the storm cranks on Tuesday. In addition, for areas that get 6"+ of heavy wet snow/paste that sticks to trees the weight along with the winds could lead to some downed trees/power lines and outages.
And don't forget to shovel before sunset and salt areas as needed, as temps will drop into the mid-20s. Also, be careful out there, but try to enjoy it if you can.
https://www.weather.gov/phi/
https://www.americanwx.com/bb/topic...winter-storm-6-12-for-many-on-feb-13/page/48/