eduggs

The HRRR was a few degrees too warm in Orange and Putnam. A coating of snow down to nearly river level with accumulations increasingly quickly with elevation. Turned into a snowy evening with snow mixing in at 500ft in Morris County right now. The less snowy NAM runs appeared to do better than the HRRR or RGEM which showed mostly rain until well NW. Actually the ECMWF and GFS did pretty good with the lower level temp profile too I think.

Looks like a burst of rain and snow coming... probably elevationally dependent. Bright banding evident on radar.

In terms of surface weather it's mostly a miss with snow showers and C-1" with more in SNJ. But I agree aloft it's the closest I've seen in a few days to a bigger solution with the PV dropping into the trof and amplifying it almost to a neutral tilt.

FWIW, the RGEM at 84hr looks more like the 18z ICON than 0z. The RGEM has a more pronounced shortwave over the Dakotas and the PV is further north. The 0z ICON is much more suppressive with lower heights / the PV through the Lakes.

I'd take those ECM runs every time. Weekend, daytime snow. 8-12hr duration. Temps freezing or below. We pray.

I get the pessimistic sentiment. I feel it too. But the reality is we just don't know how things will play out. Some of our best snowstorms seemingly came out of nowhere. And the positive surprises are more fun than fretting for a week about a modeled blizzard that might disappear.

Sunday isn't lost yet. The next day or so will likely resolve whether or not this is a potential wintry threat. The ICON, ECM-AI, GFS-AI, and GEFS support a possible snowstorm. The other guidance (UK, ECM, CMC, GEPS, EPS) aren't too far off.

Yeah good to see the GEFS mean with a slight improvement over 12z and better than the op. Every step in the right direction is welcomed. This next 24 hours of modeling will likely reveal if this will be a wintry threat or not.

Far NW suburbs still on track for a possible C-2" tomorrow. Unlike last week which was more of a latitudinal gradient, this potential wintry event has a stronger elevational component. I could see the top of Schunnemunk or Mt. Beacon getting an inch or two of snow while the Hudson River towns get zilch. Elevated NW NJ could get a little accumulation this time too.

The 12z NAM family has an advisory snowfall for NW burbs (Sussex, N. Morris, Orange, Putnam) probably above 300ft or so. But there's no support from the other meso models. The NAM also keeps it going for longer. Other models are warmer and shorter duration. I'd sell the snowier outcome for now but keep an eye on the mesos tonight. The airmass is cold but the southerly flow will warm things quickly tomorrow. The multi-day trend of a higher amplitude trof has delayed the onset and pushed the initial overrunning well north of us. That hurts wintry chances outside of hill towns.

There's pretty good support for some wintry precipitation for the I-84 corridor early Wed. This has been trending colder for several days. Some guidance gets it as close as Morris, Rockland, Westchester counties. A cold Tue night will give some a chance, but the boundary layer will warm quickly early Wed. Does the initial precip. pass well to the north and then basically a cold front passage, or does it shift far enough south for a few hour burst of snow/IP/ZR... something to watch...

You seem to have a very narrow and rigid way of looking at weather and statistics. That's fine. Considering the relatively small sample size of seasons and the highly variable nature of local weather, I prefer to use a less rigid framework when assessing future possibilities... just a difference of preference and interpretation.

12z NAM (12km) is a little less snowy then 6z. But the 3km is still pretty cold. It has brief snow to ZR and back to snow. I'm not sure I buy that scenario. This looks more like frozen to rain to cold/dry with flurries to me. Either way... interesting solution. As modeled, the 3km NAM is cold enough for travel impacts N&W of NYC. I'm skeptical since surface temps tend to overperform warm with a SLP to our northwest. But other guidance is pretty cold too... so we'll see.

We don't need a benchmark track or a major snowstorm. There are a hundred ways to get snow in our area. We just need a little luck with shortwave evolution. Sometimes "suppression" favors coastal Georgia, and other times it favors our area. It depends on minor details in the upper level and its progression. I believe it is wrong to lump everything into a box to try to explain it considering the forces that drive weather are extremely complex and variable. Every day, every weather map, every situation is unique. This year Chicago, Albany, NY, Richmond, and Mt. Mansfield are way ahead of ave. snowfall to date. That random list of cities could easily have included NYC with minor changes to how events played out.

NAM, HRRR (end of run), GFS, ECM are all pretty cold (and a little snowy) for Wed morning NWNJ and I-84 area. The Canadian and RRFS are a little warmer and pivot the steadier precipitation a little north of the area until the boundary layer warms. I'd like to see this evolve into a 1-2" deal for Sussex, Orange, Putnam with flakes (coating?) or sleet into northern Morris, Passaic, Rockland, Westchester.

And the southern Piedmont of Virginia

Most models have a little bit of snow on Wednesday for approx. I-84 north, favoring elevation and especially latitude. This has been trending slightly colder for several days. I think it will be tough to accumulate much with a surface low near Lake Ontario... but considering Tue night is likely to be fairly cold, if precipitation comes in a quick burst I think there could be some minor accumulations before the boundary layer quickly warms. A slight model shift colder would help, but guidance has been very consistent curling up this shortwave west of us.

Anybody notice how far south the Wed shortwave has gotten on the GFS? It gets the 500mb 540dm contour all the way down into the Carolinas this run (0z). It's been steadily shifting south for maybe a half dozens runs now. It probably doesn't mean much given the relative short range (and lack of support)... but any further south and northern parts of the region would be in the game for some wintry precip. The Poconos are already in the game. I-84 region is borderline.

It's pretty cool to see embedded bursts of steadier snow with real snowflakes and maybe 1mi visibility. These bursts are evident on radar as parallel bands oriented transverse to the direction of movement. Model soundings were reflective of the low level pixie dust stuff that's forming below the radar beam. But the heavier banded stuff is actually showing up on radar and accumulating.

Pretty snowy night out there. Alternating flurries and light snow with intensity gradually increasing since 9pm or so. Probably a few tenths accumulation on all surfaces... could be some slick spots. Nice job by the hi-res models even days in advance. I'm not sure how well models would have picked this up 15 years ago.

Same here in central Morris County (except for 26F). Been snowing on and off for several hours. Mostly snow grains.

Saturation is below the snow growth zone. The moisture is very shallow. That's probably snow grains and/or ZR. Not impossible a few spots get lucky if lift/saturation is more robust than modeled... seems doubtful for now.

The low level moisture moving in on a SSE flow is already visible on radar off the NJ coast. If it's ZR, I can see short-fused advisories being posted. I hope it's snow/snow grains instead.

The 18z 3km NAM has 0.1" liquid for part of the region tonight. I'm skeptical that it can accumulate much due to snow growth problem. But sometimes these low level lift/crystallization events that linger for several hours over an area can surprise. I'll take the under for now.