eduggs

I think it improved early in the run but then shifted east at the end. The ICON did the same.

Noticable shift ESE with the PV on the 18z NAM. Looks more suppressive. Bummer... was really hoping to get lucky with this one and keep trending it. Although it shouldn't be surprising that the outlier solutions shift towards model consensus.

The 12z CMC is the first run I've seen that fully rounds the base in time to spin up the mid/ULL into Nova Scotia. Too late, yes... but closer. The next step would obviously be for it to happen faster and in time to impact EMA instead of Halifax. ... gotta keep pumping heights out ahead of the trof in Ontario/Quebec.

Regarding trend analysis. You should include hypothesis testing and p-values to assess the statistical significance of the trend. Most random scatterplots will show a non-statistically significant linear trend... so you have to analyze if the trend means anything. By visual inspection, the negative trends are largely due to lower-snow years starting in 2015. It could be argued that this down-cycle explains the trend and will be reversed after the next up-cycle. I do believe warmer winter temperatures are affecting seasonal snowfall. But snow is a tricky parameter to analyze and statistical analysis can be very misleading if not presented faithfully.

GEFS mean keeps ticking a little "wetter." NYC just shy of 0.2 liquid now.

Good trends at 12z so far. UK kind of splits the difference between the RGEM and NAM.

It was the opposite - too warm - down in NNJ and SENY yesterday. Showed rain in areas that got accumulating snow.

How far east do snow showers and squalls make it this afternoon I wonder? There could be some training of the lake effect band. Parts of the Poconos will likely pick up an inch or two. NWNJ could get in on the tail end of the action too if we're lucky. Probably not much accumulation east of PA, but flakes are always nice to see.

For the center of this forum's region, as depicted, the 12z NAM would bring warnings snows, the 12z RGEM would bring an advisory, and everything else that's out (ICON, RRFS) would bring sub-advisory light snow/flurries.

The RGEM clearly has less precipitation than the NAM. The RGEM is around 0.3 liquid for the greater metro area with a little more in C/SNJ and a little less in NWNJ and SENY. The NAM is double that... around 0.6 liquid for all of the metro, LI, and NENJ, with less north and south. The NAM (likely overdone) is a great run. The RGEM is a good run. Both were encouraging relative to last night's runs.

The NAM is an outlier right now in the upper levels. It shows a trof structure further west and less positively tilted than everything else. But it also trended better than 6z. It would be very encouraging to see big moves towards this today. The 12z NAM would also feel a lot snowier than what most think of when they see 3-6". That's weekend, daytime snow with cold 925mb temps, near freezing surface, and probable banding. It's a great and unlikely outcome.

I was speculating where I think this is heading, not summarizing what all models are showing. I hope some of the wetter AI model solutions are right. But even they are relatively dry outside of southeastern areas. And they haven't shown a clear positive trend either. The trof is positively tilted and the PV is pretty far east. That's not a great height field orientation to work with... especially as we approach the short range.

I don't think the 0z NAM is much better aloft, if at all, than 18z. The RGEM is a little worse. The GFS and ICON are a little better. Kind of a wash so far for 0z. I think this is heading towards a scraper or light event unless we see clear positive trends very soon.

Some modeling shows possible snow showers or squalls tomorrow. Something to keep an eye on... despite the lack of "snowstorms" so far this year, I've seen snow a lot more to date than the past few years. The vibe feels different.

Turned into a pretty snowy evening for NW burbs especially with some elevation. As already mentioned, the NAM, GFS, and ECM did pretty good along the southern periphery of snow. HRRR and RGEM not so much - too warm. Apart from the ECM and ECM-AI (haven't seen?), 18z wasn't great for this weekend's potential event.

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.