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Don, if you go with uncertainty analysis or probabilistic analysis, then I think we're on the same page. But not sensitivity analysis. Early in most months it should be close to a coin flip whether the month will end up above or below normal. Our climatic base state relative to previous decades is warm, so we hedge warm to start. And then Bayesian updating based on long-range modeling.

Of course not... but this isn't about the virtuous journey in pursuit of objective understanding in here. You kidding? You're dealing with weather drama -related dopa addicts LOL The dealer got arrested and didn't make the scene - so now your attempting to explain that to withdraw rage. Hey, more power to ya -

Yeah, It would be cool if we knew how many hr 384 KU's that the GFS use to have that actually worked out.

Wild guess here but, I'm betting few or no one is going to be interested in this. I'm actually curious at this point if we can hop-scotch our way through this +d(PNA) without getting anything at all like these ICON's and GGEM ideas. This thing has been plagued by this the whole way. Seems even in a +PNAs the fast nature of the circulation foot is crowding and not letting kinematics be conserved at small scales (cyclone) in lieu of the frenzy in the hemisphere...

So much boredom . So much

The January 15-16 event was highly unlikely to be a big snowstorm from the onset even if some social media accounts warned of a "big one." Aside from occasional operational GFS runs (unsupported by the other guidance and the various ensembles), no big event was on the table. Three important reasons apply: 1) The AO-/PNA+ pattern is just getting established. The trough was not likely to be sufficiently sharp for January 15-16. 2) There are numerous areas of vorticity competing with one another. The probability that the various areas of vorticity will develop into a single consolidated low that takes an ideal track for a classic NE snowstorm is low. Large splashes of color on vorticity maps don't always translate into surface potential. Neither do deep 500 mb lows. There's a lot involved for the upper levels and surface to become aligned. 3) The realistic scenarios of a light impact had been available for some time, even as the exact solution was outside the range of the guidance regarding the ability to resolve synoptic details. During the 1/11 0z EPS cycle, a single ensemble member had 6"+ snow (none had 10"+) and during the 1/11 12z EPS cycle, no ensemble members had 6"+ snowfall in New York City. For Boston, the figures were 6 and 4 members respectively. Bottom line: the probability of a significant NE snowstorm was low; the probability of a major NE snowstorm was extremely low. Based on the above three reasons, I never incorporated the idea of a significant or major snowstorm into my daily posts regarding the January 15-16 timeframe. If one is constructing a checklist, one needs both a favorable pattern and favorable synoptic details to get a KU-type snowstorm. If either is lacking, the probability of such an outcome is low. When both are lacking (as is the case regarding January 15-16), the odds are close to zero.

I've been thinking...I actually don't think its a bad idea to start threads for specific storm threats, even if the probability is low. It would be great to start like building a library so to say for research purposes. We have so much research and data on storms which worked out but I don't feel like we have much of a database on storms which don't (outside of the section in the KU books which as some near misses). It would be cool if the board also had like an archived section where specific threads could end up there for historical and research purposes.

We haven't even had a single model graphic posted in this thread. Its that bad.

So finished a stretch of overnights ydy morning, and slept in long, so just looked at everything in the last hr, including previous runs. It's odd. You look at the solid full latitude 500 trough and it axis, and you wonder why a weak wave scoots out quickly ahead of the upper support, taking the baroclinic zone w/ it!!! Looking at 500 alone, it should much better at the sfc for a decent coastal. Also, now the models don't develop any real strong sfc low? Huh? Again, the 500 alone does not suggest this should happen! Big difference than 24 hr ago as well. The 500 cuts off *well* W of New England and is stronger than ydy, and moves over right over the region. That should promote a sfc low *not* scooting out to sea. However, it's not titled below. The 700 low is co-located and goes right over the region, so we get dry slotted! But we never got any sig precip to begin w/! CoastalWx's worst nightmare! LOL. Moisture is quite limited w/ the upper low, so that will just mean half-decent snows across the mtns of NNE probably. Ydy was better actually, since the 500 low cut S of the region. And the two decent troughs that occur down the road, can't do much either, at least on the 06z GFS! The 06z ECMWF looks better for something this weekend. It's been piecemeal in regards to snowfall across the region so far this winter, no one storm can deliver widespread mdt-hvy SN. Just sub-regions, like LI to Cape Cod and NNE get localized decent snows. Now, we get a fragmented storm coming that that can't consolidate right!? I can see now why CoastalWx is really getting ticked!

Sorry Don. You're not a statistician. And what you describe is not sensitivity analysis.

I'm a huge believer in Jan 23-Jan 28. Legit cold, OPs throwing out consistent hits (some historic) in the long range, great snow/precip means, etc. Don't see what isn't to like.

lol this place cracks me up.

Bullying works in this context. The young ones always go thru this transition. Some slower than others. But they get there.

Line that can up, I’m about to boot that sumbitch with my steel toes. Lolol we’ll get a win here soon yall!

For those who are not familiar with it, sensitivity analysis incorporates uncertainty into an assessment. It is not deterministic in nature. It is not a point estimate. After the first 11 days of the month, the probability of a colder than normal January was just 55%. That means that there is still a lot of uncertainty. One sees it in the varying ensembles and weeklies and the lack of run-to-run continuity in cases. That's the key takeaway from any sensitivity analysis. It's capturing the large amount of uncertainty quite well, assuming one knows what one is looking at with the probabilities. For perspective, back in December, the estimated probability of a below normal monthly anomaly was 89% on December 7th. That was about as close to a "slam dunk" as one can get at such a long lead time. The estimated monthly mean temperature then was 34.0° (December finished at 33.8°). The major weakness is that the analysis assumes a Gaussian curve (normal distribution). Not everything is normally distributed. This assumption is necessary, because the kind of detailed model verification data that would be needed to construct a more robust curve is not publicly available. Thus, the simplifying assumption of a normal distribution is used. Finally, I include the estimated monthly mean temperature only because it's nice to have. But one should know what one is looking at. The estimated mean is similar to an ensemble mean, while the probability of an outcome plays the role akin to an ensemble spread (low probability reflects a large spread in outcomes due to high uncertainty). IMO, the probability of an outcome (I just use below or above normal) is really the more useful element of the piece concerning sensitivity analysis, especially at long lead times.

Not surprisingly, today’s GEFS mean prog has reduced the max amp of the phase 6-7 from the ~2.7 of two days ago to now being close to the Euro’s ~2.1 today (see below). But it retains the 17 day record breaking long winter phase 6. Also, note that today’s GEFS turns it left as it approaches phase 8: Yesterday’s ext GEFS didn’t turn as much: This change should be respected based on the stats for the # of DJF MJO days by phase since 2011 showing that phases 6/7 were the two most frequent phases day by day and that phase 8’s days numbered only ~1/3 of that of phase 7, which is likely due to the strong W Pac warm pool (where phase 7 resides): DJF: 1: 76 2: 96 3: 167 4: 173 5: 212 6: 249 7: 286 8: 95 Whether or not the MJO actually goes into phase 8 late this month and then proceed to 1-2-3 in the first half of Feb will probably play a big role as regards the chance for the +PNA to come right back (if it were to actually go back to a -PNA for ~a week just prior) and the resultant resumption of a cold E US as we look toward the 1st half of Feb. If it ends up not going into phase 8 in a meaningful way, the last 2 Euro Weeklies runs showing a mainly mild Feb would seem to have a better chance to verify. Let’s hope not for those who want it cold. @donsutherland1

2006 as well.

Should never start specific storm thread at this lead but we all knew the motive for it.

Yep. Known biases. Now, the biases change with the system.

Who is this dude and what did he do with the real bncho? But for real the post quality improved vastly and quickly haha

Make it 12 months of winter!

Nice! We had some mood flakes while driving home from Farmington last evening. Snow squalls are admittingly hit or miss, but we get the miss at a high percentage, except when we lived in Fort Kent where they were common.

Agreed, and I don't know what's up with March this decade but there's only been snow in March 2022. The rest of the years have been snowless in March. March 2020 and 2023 was good for New England but mainly rain for us.

Anecdotally, this is the 2nd slowest start to winter storm names by the weather channel. I'm sure I'll get weenied for this, but I'm just introducing this evidence to show how dry it has been this winter. The slowest start to winter storm names by the weather channel was last winter, 2025. The weather channel isn't the best at adhering to their own criteria when naming the storms (2 million+ people have to be under winter storm warning in order for it to be named), but they're pretty good at adhering to their criteria aside from a few exceptions. Just goes to show how dry the past 2 winters have been. In 2023 and 2024, the lack of cold air was a problem for many east of the Plains. But in 2025 and 2026, there hasn't been a shortage of cold, there's been a shortage of precipitation. Almost like winter in the 1930s lol

Snow is good anytime, but February is melt season and often the beginning of mud season. December- and January snow is more emotionally and aesthetically valuable at our latitude.