Isotherm

Unfortunately, the continental USA will be devoid of polar air during the time-frame of greatest PNA amplitude. So, even conducive storm tracks could imply rain rather than snow for the I-95 corridor. Due to the fact that we are at the climatological height of winter, marginal airmasses can potentially work for interior areas.

Same: only 18.8F, which is fairly incredible when one considers my average lows are in the lower 20s. We've made it through 20 days of January and have not see an overnight low more than a couple degrees sub-normal.

Yes, I agree with your post here and the others recently. Regarding the putative canonical Nino-look and seasonable temps in the South, that doesn't necessarily imply favorable pattern for snow in the Northeast I-95 corridor. Classical Ninos are typically seasonable temperature wise across the southern tier of the CONUS due to frequent clouds and precipitation. For example, see 97-98, which wasn't a torch for the southern half of the country, but it certainly wasn't snowy for our region. Similar look with 1982-83.

Thanks, Chris. And great explanation above as well. Another factor supporting the notion of potentially a better window of opportunity late Feb-Mar is the wavelength alterations. The shorter wavelengths in late winter-March can often render than base state -PDO/-PNA less influential. I do not have the data in front of me, but I would wager to assert that a proportionally higher % of snow events in March featured a -PNA compared to Dec-Jan-Feb. @uncle W may have those statistics. Until late February, we may continue to battle this unpropitious base state.

Likely because the skill scores are substantially lower. The EPS bias in our region was negligible in the recent 11-15, while conversely, the GEFS bias was significant.

Well - it's something. 1.0" total here. IP/ZR now. 28F.

Surface southerly winds inland from the coast will be light through late afternoon: Temperatures rise during the evening on stronger southerlies:

23.2/2F here. This is a good resource for water temperatures. Readings presently around 46F near Sandy Hook, hence why light southerly winds are desired, and those on the immediate shoreline will have difficulty accumulating more than a trace to 0.5". http://www.fishtrack.com/fishing-charts/northeast-us_61130

The periodicity seemed to be apparent from the 1930s-1990s, with ostensible biphasic signature. However, since about 2000, during the time wherein we should have descended into a negative PDO, we have averaged positive (especially after 2013 we detached from the cycle). So, it seems the PDO has become statistical noise when one measures the past 25 years or so.

That is partially the issue. -PDO promotes -PNA in the means, and MJO coherence/amplification in autumn has a much different effect on the circulation across the high-latitudes, due in part to wave-lengths, as well as a typically more decoupled stratosphere-troposphere. The SSTA profile of 2002-03 was more conducive for troughiness south of Alaska, which teleconnects to PNA spikes in the classical location, sufficiently far east for us. There is often much chatter and excitement about the warm pool south of Alaska, but from my perspective, I tend to think a cold pool is more felicitous. This is a classic +PDO structure.

It is quite interesting, Chris, and I've been ruminating on some hypotheses re: the time-lag and distorted response. One issue, in my view, is base-state resonance. Sometimes the MJO/intraseasonal signal is misaligned with the base state, and as such, when it propagates through typically conducive phases, the N HEM response may not be bonafide/favorable due to the misalignment with the background indicators. For example, 2002-03 had a much more classic AAM/GWO and hadley/walker cell structures concordant with a canonical El Nino, and thus when MJO circulated to 8, we had a more genuine N HEM response. Another issue, the PDO has become much more negative over the past month, as last winter was. This amplifies -AAM resonance and retards proper +AAM transport.

Indeed. One can see the modeled tropical forcing returning to those spatial domains in February, which will play a role in the developing February regime as delineated in my update post.

Agree as well. Hopefully, we can pick up an inch or two here in Monmouth County. Unfortunately, temperatures here likely rise to 40F after the snow ends, otherwise, we could have maintained that little bit of snow on the ground for several days, given the colder temperatures next week. Yes, the past couple of winters have been a bit of a throw-back to the mean storm tracks of much of the 80s and 90s which favored the interior, and numerous snow to rain events.

Unlike every other event this season hitherto, this one includes a much better antecedent airmass over the local region. Thus, rather than little to nothing, I think it is possible for NYC to record 1-2" of snow tomorrow. EWR/locations immediately NW of NYC could potentially see 2-3". Southerly winds will take several hours to scour out the dense, low-level cold and low dew points.

Thanks -- and I did, and when I stumbled upon it, was fascinated that we arrived at similar conclusions via disparate pathways. His index essentially asserts the same: that this MJO response will be distorted/non-classical as far as the NHEM impacts, and that is due mostly to the reduced ACWB via the convection/momentum transports. Thanks, if I had to alter anything versus my initial February depiction, if anything, February might be slightly less favorable than I thought in November.

@frd -- I posted updated thoughts in the main board and NYC forum which may be of interest re your inquiry. Pre-season, I highlighted the fact that the westerly shear stress in the stratosphere/z30 would be obdurate [i.e., weakly positive QBO remains presently], and when coupled w/ suppressed solar backdrop and other proxies, actually favors a very stable vortex. In fact, that particular permutation most favors the stable vortex. Usually, disruptions don't occur until late winter. That, in concert with other variables accounted for in my NAO formula, indicated generally low-gepotential heights across the NAO/Arctic domain for this winter. In my update post here, I discuss the remainder of the winter. I think most of February will probably be +NAO, but the window for NAO blocking would initiate late Feb-March if it does this particular year:

Updated thoughts on the pattern, posted in my winter outlook thread: Key points included therein: brief recapitulation of winter to date, largely concordant w/ expectations, MJO's distorted response, RNA structure in February, late winter opportunities.

My presumption is that your inquiry was directed at the poster you quoted, rather than a general/non-specific inquiry. If the latter -- certainly (as I'm sure you know) -- there are a multitude of indicators to employ other than [in addition to] model guidance, including veridical atmospheric phenomenon(a), which produce scientifically known, pleiotropic effects hemispherically/globally. Speaking for myself, my starting point with any medium to long range forecast is observation of certain forcing mechanisms, i.e., the existence of deep tropical convection persisting over a certain spatial domain, i.e., westerly shear stress via +QBO in the stratosphere, i.e., atmospheric momentum deposits, torque and wind-flow patterns, etc., and then using that knowledge as a basis to form judgments regarding the likely resultant z500 outcome. Then, if model guidance in the medium-long term differs from my expected outcome based upon the totality of the circumstances analysis of indicators, it is prudent to dissent from those model projections. Note: I'm only speaking generally and not with reference to the specific pattern here. However, this was to respond to the inquiry you posed re tools available to employ.

Yes, verbatim, those projections would indicate forcing reaching phase 8 (though at a much lower amplitude) by Feb 3rd. Those plots were also derived from Roundy's website.

Keep in mind, the phase 7-MJO response is still a warm one for the E US, although cold-air transport into the Plains increases. One would need continued propagation into phase 8 at amplitude for potential/putative pattern amelioration [and as discussed yesterday by Bluewave and I, propagation into 8 is not necessarily a guarantee of a significant pattern change, either -- many factors involved].

Thank you, @griteater. Will be interesting to see the evolution of the rest of the winter. Not over yet, but so far, things have/are going generally per my expectations.

Thanks, Chris. In addition to that warm pool to which you describe, another issue, IMO, was the transport of momentum generally south of the equator w/ that intraseasonal MJO passage last February. Note the z850 zonal wind anomalies; most of which were directed south of the equator [circa 5-S latitude], so we didn't benefit as much in the northern hemisphere. Indeed - My total snowfall after February 15th last winter was 6.9", while the entire Dec 1-Feb 14th period featured 2.8". Certainly an improvement - though not to a very favorable regime - but better than nothing. It will be interesting to see how the rest of this season evolves.

I think wave-2 activity will increase later this month, but whether it's sufficient to induce a technical SSW is indeterminate. Probability is lower than normal this season, in my view, for one to occur. However, regardless of what happens with the stratosphere, Feb-Mar had/have the highest potential (compared to Dec-Jan) for some improvements in the Atlantic-Arctic domain.

Thanks for that data; it certainly confirms our suspicions. That additional energy inputted into the budget across the tropical domain will certainly serve to decelerate and amplify the intraseasonal-MJO signal as it propagates ewd.