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February 2019 Discussion I


NorEastermass128
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Euro is all alone on the battlefield with Monday lots of time to watch. I have noticed a trend LR for a big ridge overhead day 9ish. We probably need to get this done next week or we lose the STJ. Damn though, agreement across all modeling for big rains in the Tennessee valley with amounts over 10 inches . Some indication of a Positive PNA to end the month. 

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27 minutes ago, STILL N OF PIKE said:

I dont see a -NAO happening so should we lose the -EPO the pattern would truly morph into something that shows us what a suck snow  pattern truly is for all (not just s coast) 

I'd take that. I'm done with the 3" snows followed by rainers.

Bring on the torch, if that's the case.

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10 hours ago, Isotherm said:

Winter 2018-19: A Re-analysis

 

Science is all about advancement, usually due to anomalies that emerge spontaneously in any given dataset. Most scientific advancement occurs not as a function of status quo, but because something atypical, aberrant has arisen in any given field, and the scientists who are independently minded (and financed) enough to pursue those anomalies, are generally the ones who pioneer and "break ground."

 

Before I get into this, just as a disclaimer: it is still entirely possible that there's a "late-game comeback" with respect to this winter, but, it is apparent enough to me at this point, that the winter deserves/warrants a re-analysis post of sorts, regardless of how we finish over the next month, which may or may not ameliorate the widespread busts of this winter. 

 

Over the past few weeks, I've used some time to investigate, and believe I have a cogent hypothesis regarding the failings of this winter. In retrospect, I am rather disappointed in myself, being one who tries to be as meticulous as possible in research, that I missed this; however, it's easier to say such in hindsight, and I may not have detected this, but for the miscalculations of this winter.

 

We had quite a bit of +AAM in the atmosphere this winter, but I think to some extent, in not exactly the "right" places, to induce the necessary countervailing easterlies in the high latitudes. The lack of FT cooperation courtesy of the meager Nino forcing was a major factor, which would have produced more sub-tropical westerlies / +AAM, initiate the STJ, form sub-tropical TROUGHS, and thereby weaken the polar jet. We have had a lot of sub-tropical RIDGES this winter, more La Nina like. 

 

I do strongly believe the issues with respect to this winter's failures goes even deeper. Retrospectively, the tropical forcing pattern during much of autumn 2018 more closely resembled a La Nina, w/ subsidence large-scale over the Pacific, and more uplift over the Indian Ocean. This did attempt to flip somewhat in November, which is partially what led me down the putative rabbit's hole, prior to reversing back toward a Nina-esque tropical forcing regime in December. This was an aberration year in which November's regime certainly did not augur the mean winter pattern.

 

Additionally, the positive 30mb QBO hurt us and destructively interfered more than anyone thought in my opinion. We were expecting that the -50mb QBO, which has high correlation to SSW events (that truly helped!) would countervail. Unfortunately, yes, the negative 50mb QBO produced a SSW, but it also tends to intensify the MJO/intraseasonal signal.

 

Along that vein, I actually think this winter was too UNSTABLE in a number of ways. The MJO simply did not cease: constant propagation from amplified phase to phase, obviating any stable PNA or cold pattern from becoming locked in, compared to winters in which we stabilize in the colder MJO Nino phases. The negative 50mb QBO and thereafter the massive SSW only aided further to augment the incessant MJO signal.

 

Then, the 30mb QBO, which I now think is really more important than the 50mb QBO, aided in stabilizing the tropospheric polar vortex, and decreasing the very necessary tropospheric receptivity to blocking. The unpropitious 30mb QBO, the negative 50mb QBO induced intraseasonal amplification, unstable MJO, and Nina-esque forcing, precluding FT cooperation, sub-tropical +AAM, sub-tropical troughs, and polar easterlies -- were all the factors in my opinion.

 

Furthermore, the negative 50mb QBO, coupled with the cooling tropical stratosphere as a function of the major SSW event (I have noted this before), and the abnormally warm off-equator SST's in the West Pacific, aided in expanded hadley cells, poleward / retraction of the northern stream, yielding a less amplified, more disconnected, Nina-esque type of paradigm. Further, the very cold tropical stratosphere led to a convective disarray, much like a low-cap T-storm day, wherein destructive interference from rossby waves, and MJO amplification in the warm phases was frequent. 

 

The NAO has been trying to go negative this season, evincing pretty positive geopotential heights over Greenland, but the Azores/sub-tropical high never departed, which has kept the NAO calculation technically slightly positive thus far. I think that's Nina-forcing and QBO induced largely. Notice in the below composite, and you'll see even on model data going forward, we try to achieve the higher heights in Greenland, but it doesn't DISCONNECT and DETACH from the Azores sub-tropical high, thus, Europe remains mild, rather than the classic undercutting jet -NAO signal.

 

f57k9x.jpg

 

 

Regarding the AAM point; this is a highly unpropitious / unfavorable diagram right now, if you're looking for high latitude blocking of significance. +AAM in the wrong places. The belt of easterly/-AAM deposits in the sub-tropics tends to induce more nina-esque sub-tropical ridges, and indirectly, intensify the polar jet, tending to countermand sustained blocking.

 

http://gsdmsolutions.com/~gsdm/clim/daily_total/glaam.sig.90day.gif

nfjwcj.gif

 

That needs to alter for any major blocking to occur.

 

Finally, this particular QBO permutation (similar to this year) has only occurred two times since the late 1970s, namely, a +QBO descending at 30mb while the easterly -QBO at 50mb maintained. Those two years were nina like, with amplified intra-seasonal signals. One of those winters was one of the worst winters on record snowfall wise in our local area. 

 

Now, with all that being said, these are hypotheses, and correlations, with arguably debatable causation chains, but evidence of causality in meteorology is quite difficult as it's nearly impossibly to control for confounders and isolate the pertinent variables. Nevertheless, I am satisfied with re-analyzing this winter, and I will certainly not make this particular mistake again.

 

A short summary of the problems: The Pacific was the largest problem; stronger blocking would have countervailed, but that wasn't the principal issue. The AO will average slightly negative for the winter, and the NAO probably near neutral to slightly positive. It was the pacific - due to reasons expounded above, and secondarily, the lack of more effective blocking, intraseasonal amplification / hadley cell expansion, due to the SSW and QBO as well as SSTA profile.

 

As far as the remainder of this winter: the WWB looks good, as does the MJO propagation, but will the atmosphere respond? Or will the Nina-esque tendencies w/ atypical AAM distribution, and dichotomous QBO keep the blocking muted? That seems to be what models are currently indicating.

 

Like I said, there is a chance for a late-game "save," and then, hopefully, all of the above will simply be good, abstract discussion regarding my take-aways going forward. On the other hand, if there isn't a late game save, the above is effectively a post-mortem on the issues underpinning (in my opinion) this winter's miscalculations by virtually everyone if not everyone in the meteorological community this winter.

 

Thanks for reading.

 

Tom

 

A short summary of the problems: The Pacific was the largest problem; stronger blocking would have countervailed, but that wasn't the principal issue. The AO will average slightly negative for the winter, and the NAO probably near neutral to slightly positive. It was the pacific - due to reasons expounded above, and secondarily, the lack of more effective blocking, intraseasonal amplification / hadley cell expansion, due to the SSW and QBO as well as SSTA profile.

The last man standing has folded.

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49 minutes ago, 40/70 Benchmark said:

The last man standing has folded.

 

Ray, while that is effectively my prepared post-mortem, I do think there's still a chance the last few weeks of winter produce a good pattern, but that will be contingent upon scouring out the -AAM in the sub-tropics [finally erasing the sub-tropical ridges], to allow the jet to cut underneath in the Atlantic, so a bonafide NAO develops. We should see some PNA improvements in the last week of this month.

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6 hours ago, dryslot said:

Not with that one, But numerous ones in the 240 range that won me some $$$.................;)

We could have a weenie league.  I bowled a lot back in the ‘90s.  Averaged was around 235.  My high was a 293.  Oh so close.  I’m afraid of what a score would look like today.

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4 minutes ago, moneypitmike said:

We could have a weenie league.  I bowled a lot back in the ‘90s.  Averaged was around 235.  My high was a 293.  Oh so close.  I’m afraid of what a score would look like today.

Sounds like nerves got to you in the 12th.............lol, It took me quite a few tries, Got to the 10th on several occasions only to leave a pesky ten or come up a hair high and leave a 4 pin, I have a 297 too, That was a bad shot that went brooklyn...............:cry:

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26 minutes ago, Isotherm said:

 

Ray, while that is effectively my prepared post-mortem, I do think there's still a chance the last few weeks of winter produce a good pattern, but that will be contingent upon scouring out the -AAM in the sub-tropics [finally erasing the sub-tropical ridges], to allow the jet to cut underneath in the Atlantic, so a bonafide NAO develops. We should see some PNA improvements in the last week of this month.

 Very well done write up at that .

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2 hours ago, Isotherm said:

 

Ray, while that is effectively my prepared post-mortem, I do think there's still a chance the last few weeks of winter produce a good pattern, but that will be contingent upon scouring out the -AAM in the sub-tropics [finally erasing the sub-tropical ridges], to allow the jet to cut underneath in the Atlantic, so a bonafide NAO develops. We should see some PNA improvements in the last week of this month.

I'm 50/50....but may as well stick to the decaying corpse that is my outlook, and say, "what the hell".....we should get a good storm.

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4 hours ago, Ginx snewx said:

You could have just put a link in and let us know it was bad luck not preconceived notions 

I have never, ever attributed the long wave pattern to luck....not sure how many times that I have to say that I missed it...I was wrong. The fact that we have this little snow is absolutely due to crap like n stream $hit streaks, and poorly timed short waves. How else do explain near record precip surplus and near normal temps yielding snowfall numbers this paltry at this latitude.

And I'm not sure what you mean by preconceived notions...all of my work is well researched and I've been damn near dead-on 3/5 years. Even this year my temps are fine... NAO killed me. I'll do the post-mortem in the spring, as I always do.

 

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2 hours ago, 40/70 Benchmark said:

I'm 50/50....but may as well stick to the decaying corpse that is my outlook, and say, "what the hell".....we should get a good storm.

I think spectacular fails like this winter provide the best learning tools for future forecasts, so at least some good will come out of it. 

And maybe we can still salvage what's left of this disaster for the last month of true winter. 

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5 hours ago, 40/70 Benchmark said:

I have never, ever attributed the long wave pattern to luck....not sure how many times that I have to say that I missed it...I was wrong. The fact that we have this little snow is absolutely due to crap like n stream $hit streaks, and poorly timed short waves. How else do explain near record precip surplus and near normal temps yielding snowfall numbers this paltry at this latitude.

And I'm not sure what you mean by preconceived notions...all of my work is well researched and I've been damn near dead-on 3/5 years. Even this year my temps are fine... NAO killed me. I'll do the post-mortem in the spring, as I always do.

 

Well seeing as you quoted Tom and he, right in his statement, said he had the wrong idea due to a preconceived notion you might want to not take everything so personally cuz I wasn't referencing you 

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6 hours ago, 40/70 Benchmark said:

I have never, ever attributed the long wave pattern to luck....not sure how many times that I have to say that I missed it...I was wrong. The fact that we have this little snow is absolutely due to crap like n stream $hit streaks, and poorly timed short waves. How else do explain near record precip surplus and near normal temps yielding snowfall numbers this paltry at this latitude.

And I'm not sure what you mean by preconceived notions...all of my work is well researched and I've been damn near dead-on 3/5 years. Even this year my temps are fine... NAO killed me. I'll do the post-mortem in the spring, as I always do.

 

At this point it certainly isn't luck.  It's just almost straight La Niña gradient pattern.  SNE should've had a bit more snow but it's hard to deny there's something in this pattern that's caused the same areas (BTV to CAR and southern Ontario/Quebec) to snow big almost exclusively from early November through now mid-February.  

This winter hasn't been the luck of an unmanned firehose, these storms are all repeating themselves.  There has to be good synoptic reasoning somewhere for that.  I look forward to your post mortem thoughts.

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