My Winter Outlook 2018-19

[qg_omega]

2 hours ago, Isotherm said:

 

 

 

It's clear by your response that you do not understand long range forecasting. It's isn't a linear A+B+C. There are multifarious factors examined pre-season, and those indicators provide a general landscape of what will transpire for the winter. The exact timing as far as progression is more guesswork. The important part is if the forecast correctly ascertains the season overall, bearing in mind the apposite indicators.

I will not be drawn into the trap of impugning the CPC's work. However, their method of forecasting is probabilistic, and they typically err warm. 

Your post is non-scientific and provides no substantiation for your claims regarding the PV split.

I disagree but maybe that is why I do not forecast extremely long range.  To me its like a trader in a bad position and trying to justify why he is correct as he loses more and more money.  Maybe it really is a case of delayed but not denied, but its clear this winter is not progressing as many thought.  Call it the SSW, MJO, Positive SOI in an El Nino....the pattern screams pac jet and fast flow for the foreseeable future.    

[weathafella]

11 hours ago, qg_omega said:

December was forecasted by many to be warm across the conus, CPC nailed it on their month forecast issued late November.  It was clear very early on the MJO would have a prolonged stay in phase 5.  Personally, I believe the SSW event and possible split of the PV is a game changer to most winter forecasts and not for the better.  I have a very hard time with the delayed but not denied method of forecasting.  If your forecast required A + B + C + D and A failed and B was not as expected, you can't leave C and D alone as if A and B's failure don't have an impact.

I am pretty certain the actual anomalies look nothing like that forecast.  Unfortunately the data is not available until the department of commerce where NOAA falls has appropriated funds.

[raindancewx]

This is how the month looks so far, CPC did have the right idea with Utah & Maine cold in their final update. You have to give them that. I'd give it A for temps for honestly, especially with the SW likely to finish near normal given how cold it is now through 12/31.

One of the reasons I didn't end up using 1963 as an analog is the PDO was under -2 in Nov 1963. That's a huge difference maker nationally. It may seem overly simplistic, but when I was suggesting Fall 1963 looked opposite Fall 2018, my point wasn't that temps themselves are predictive, but they do tend to indicate MJO issues. I always try to line up the MJO in Oct, with timing variables, that allows you to screw up the other things a bit and not be completely off. The SOI also finished around -13 in Dec 1963, which is over 20 points out from where this Dec is currently, which definitely was not something I expected. It's screwing up a lot of things that are southern stream dependent.

http://research.jisao.washington.edu/pdo/PDO.latest.txt

[LibertyBell]

16 hours ago, 40/70 Benchmark said:

The fact that we did not get a significant snowstorm in early December was bad luck. The favorable pattern materialized, but there was simply too much confluence. Things like that can not be predicted from a seasonal standpoint.....entirely stochastic in nature.

Yes, unfortunately that seems to be the wild card in LR forecasting.  Also the fact that we have been in a La Nina type pattern for most of December.

[frd]

Isotherm, what is your take on March as it relates to the multiple VEI 3 or greater volcanic eruptions lately. I heard from some on the web and some pros at 33andrain we could see effects. Any thoughts on potential cooling effects ?

I see there is a relationship between a lower solar cycle nearing a min and increased volcanic eruptions. Thanks. 

https://www.volcanodiscovery.com/erupting_volcanoes.html

 

[qg_omega]

On 12/28/2018 at 11:56 AM, qg_omega said:

I disagree but maybe that is why I do not forecast extremely long range.  To me its like a trader in a bad position and trying to justify why he is correct as he loses more and more money.  Maybe it really is a case of delayed but not denied, but its clear this winter is not progressing as many thought.  Call it the SSW, MJO, Positive SOI in an El Nino....the pattern screams pac jet and fast flow for the foreseeable future.    

All these points remain just important today as backn in December.  Pacific remains for at least the next ten days

[Isotherm]

9 hours ago, qg_omega said:

All these points remain just important today as backn in December.  Pacific remains for at least the next ten days

 

 

Your post a few weeks ago stated the following: "Personally, I believe the SSW event and possible split of the PV is a game changer to most winter forecasts and not for the better."

Why didn't you quote your whole forecast? We'll see if your forecast is correct over the coming weeks, but the NAM reversal has already occurred, and it's quite clear to me that a protracted period of blocking is ahead. So, it's far too early to claim victory on your call that the SSW/split event will cause winter forecasts to fail or perform poorly.

Further, there's a major snowstorm ongoing currently in the Mid-west, which will carry to the Mid-Atlantic coast as a significant snowstorm. That wouldn't happen, but for, a favorable GWO/MJO circuit through p7-8, and AAM pulse. It is incorrect to assert we've been in "fast flow" the entirety of January thus far.

The only piece of your post that makes a bit of sense if that the Pacific has been problematic this winter to date w/ regards to a stable PNA structure, and I noted that in a lengthier post the other day. However, that will be altering later this month as AAM/MJO and the SSW after effects constructively interfere. But, again, I don't recall seeing your winter forecast in November, so it's much easier to see these issues after they've already revealed themselves (i.e., the past few weeks).

[dmillz25]

3 hours ago, Isotherm said:

 

 

Your post a few weeks ago stated the following: "Personally, I believe the SSW event and possible split of the PV is a game changer to most winter forecasts and not for the better."

Why didn't you quote your whole forecast? We'll see if your forecast is correct over the coming weeks, but the NAM reversal has already occurred, and it's quite clear to me that a protracted period of blocking is ahead. So, it's far too early to claim victory on your call that the SSW/split event will cause winter forecasts to fail or perform poorly.

Further, there's a major snowstorm ongoing currently in the Mid-west, which will carry to the Mid-Atlantic coast as a significant snowstorm. That wouldn't happen, but for, a favorable GWO/MJO circuit through p7-8, and AAM pulse. It is incorrect to assert we've been in "fast flow" the entirety of January thus far.

The only piece of your post that makes a bit of sense if that the Pacific has been problematic this winter to date w/ regards to a stable PNA structure, and I noted that in a lengthier post the other day. However, that will be altering later this month as AAM/MJO and the SSW after effects constructively interfere. But, again, I don't recall seeing your winter forecast in November, so it's much easier to see these issues after they've already revealed themselves (i.e., the past few weeks).

The guy is a troll lol. He does this in the NE forum all the time just to get shut down

[Isotherm]

Re: concerns pertaining to the lack of robust negative NAO initiation thus far:

 

1) Recall my last update, I noted that we would be entering a period of destructive interference post the Mid-Atlantic snowstorm, due largely to poor tropical forcing. I expected this to yield a rainstorm for the Northeast coast for the most recent event, which did occur.

 

2) The development of constructive interference, whereby the troposphere and stratosphere act harmoniously, was said to return after the 25th, in the last week of January.

 

3) The NAM has been negative; however, the weakly negative NAO ineffectual to date; why is that the case?

 

4) There's a misconception that the stratosphere entirely governs the progression of the NAO modality, but that is erroneous...

 

If tropospheric receptivity is such that conditions are unpropitious for -NAO maintenance at the z500 level, it is irrelevant what transpires in the stratosphere

 

If the stratosphere were entirely governing, we wouldn't have years w/ SSW events such as 2011 in which no tropospheric blocking resulted.

 

5) So, the stratosphere plays a significant role, but until the rossby wave train is oriented such that a proper block can retrogress into Greenland, it won't occur.

 

6) The etiology of the destructive interference lies principally in the propensity for upper divergence [convective generation] near the Maritime Continent.

 

7) This has ripple effects. It disrupts the canonical Nino-esque angular momentum cycle, by creating easterly trades in the central Pacific, lowering momentum, and inducing positive deposits in high-latitude regions which activate the polar jet such that the flow becomes too fast

 

8] Extratropical momentum pulsing attempts to countervail, but until the Maritime Continent convection [which has also been obviating proper SOI response] diminishes, a strongly negative NAO will not initiate

 

This is changing.

 

A weakly negative / transient NAO develops later this week, which could play a salutary role in the resolution of the 27-28th winter storm threat; although, it is largely EPO/PNA driven. Usual caveats apply, but it is certainly a threat to monitor, and the most conducive threat to date.

 

The Maritime Continent divergence will finally subside by the end of January. This is evinced quite ostensibly on the chi z200 propagation plots, and the easterly negative trades will subside as well, permitting emergence of more classical walker cell forcing.

 

It's not necessary the MJO itself, but overall divergence has been antithetical to proper +AAM transport through the sub-tropics and consequently negative deposits poleward.

 

Conclusion: The atmospheric pattern has changed and is much colder. The NAM has reversed, but the spasmodic NAO has permitted rainstorms for the East Coast [expected for the last event]. A real negative NAO will finally emerge as tropospheric receptivity increases dramatically by February 1st.

 

Notes and asides: Snowfall timing is the most difficult parameter of a long range forecast. However we get there - we get there. A forecaster should not be penalized for snows not being "evenly spread throughout the winter." If the final tally at the winter's end is close, then it's a good forecast. So, while there's been no snow to date, that will simply have to be dealt with. That doesn't intimate non-emergence prospectively. Key indicators and atmospheric changes were foreseen, and now we will watch the final dominos this week. I have read some comments here and there across the boards that forecasters promised a historic winter, etc., or a historic winter period; I simply want to make clear that those words never emerged from my end. My winter snowfall forecast from November for NYC-area was 37-47". This is still attainable.

 

Tom

[Isotherm]

Rapid analysis of the status of tropical forcing this afternoon: I continue to believe that alterations remain positive going forward. Westerly wind burst now progged near the dateline courtesy of the eastward propagating tropical wave, and with the MJO low-orbit, likely to continue into phase 7, then halt motion there, we should see an increase in Nino-esque long-wave pattern, theoretically.

 

Tropically induced FT will increase, torques should remain positive, as should AAM consequently, and negative -AAM deposits will continue to increase in the high latitudes.

 

The VPM index diagnosis has proven more reliable than RMM, as has the CHI Z200 analysis. All of these proxies are suggestive of central Pacific forcing near the end of January onward, w/ increased convergence, FT, etc.

 

z200 -- note subsidence emerging over the Maritime Continent by late January:

 

 

 

We recently saw this regarding the MJO : many models hit the putative brick wall, erroneously. A low-orbit signal should progress into phase 7:

 

 

 

Note guidance increasingly redolent of the dateline WWB:

 

 

 

The low amplitude phase 7 MJO z500 composite for February yields a hemispheric structure not too dissimilar from the EPS and GEFS, with fairly robust -AO and -NAO blocking, and an Aleutian low signal. The latter is what we'll see improve as we move forward in my opinion; namely, the predilection for improvements in the PNA domain. The low height signal currently progged in British Columbia should retrograde quickly to the Aleutians, operating under the assumption the tropical forcing behaves as anticipated, which it should.

 

In closing, while models are not detecting any material snowstorm threat yet for the Northeast coast, I don't see sufficient reason to push the "Cancel winter" button at this time.

 

Re discussion of putative post mortem: it's not the magnitude of the El Nino that was a surprise [weak expected]; it's the amount of time spent, and magnitude of, intraseasonal MJO activity in Nina-esque phases, as well as atypical Nino forcing w/ a weak walker cell. The forcing regime resembled NIno at times (early-mid Dec, southern snowstorm; and early/mid Jan, mid atlantic snowstorm). But the Nino forcing simply has not, to date, maintained for sufficiently long enough to provide us a large enough window within which to receive a snowstorm.

 

With the apposite variables coalescing, we'll see how we progress.

 

 

 

[Roger Smith]

From a different research perspective I am expecting a peak in retrogression and blocking in mid-February. Is there any chance that the MJO index has some correlation to externally driven factors? I have not had much time to investigate this, but the retrograde index that I use has periods like 90 and 120 days (won't say more precisely what they are outside a research paper). And is the MJO a retrograde feature or random in its movements relative to longitude? 

I have thought all along that this would be a difficult winter to forecast because of the competing influences of El Nino (a warming influence) and the combination of low solar and prior negative anomaly buildups in a source region (central arctic of Canada). Rather like saying your football team has a strong offence and almost no defence, will you be favored to win or lose?

[40/70 Benchmark]

@Isotherm Tom, are you concerned about your DJF seasonal call for a mean neg NAO?

[winterymix]

Isotherm, very intelligent analysis.   Thanks.  To be honest, I'd appreciate (from anyone here) any online links to articles in the public domain that could assist me in understanding the scientific principles that support the analysis located above.  I already know some stuff about ENSO, MJO but am looking for articles that describe (for the non-meteorologist) how to understand the forcing between the differing atmospheric phases.

Long story short, this winter seems to be like so many others in that an unfavorable Pacific requires two-thirds of the winter to make a favorable shift.

[LibertyBell]

On 1/21/2019 at 11:24 AM, Isotherm said:

Re: concerns pertaining to the lack of robust negative NAO initiation thus far:

 

1) Recall my last update, I noted that we would be entering a period of destructive interference post the Mid-Atlantic snowstorm, due largely to poor tropical forcing. I expected this to yield a rainstorm for the Northeast coast for the most recent event, which did occur.

 

2) The development of constructive interference, whereby the troposphere and stratosphere act harmoniously, was said to return after the 25th, in the last week of January.

 

3) The NAM has been negative; however, the weakly negative NAO ineffectual to date; why is that the case?

 

4) There's a misconception that the stratosphere entirely governs the progression of the NAO modality, but that is erroneous...

 

If tropospheric receptivity is such that conditions are unpropitious for -NAO maintenance at the z500 level, it is irrelevant what transpires in the stratosphere

 

If the stratosphere were entirely governing, we wouldn't have years w/ SSW events such as 2011 in which no tropospheric blocking resulted.

 

5) So, the stratosphere plays a significant role, but until the rossby wave train is oriented such that a proper block can retrogress into Greenland, it won't occur.

 

6) The etiology of the destructive interference lies principally in the propensity for upper divergence [convective generation] near the Maritime Continent.

 

7) This has ripple effects. It disrupts the canonical Nino-esque angular momentum cycle, by creating easterly trades in the central Pacific, lowering momentum, and inducing positive deposits in high-latitude regions which activate the polar jet such that the flow becomes too fast

 

8] Extratropical momentum pulsing attempts to countervail, but until the Maritime Continent convection [which has also been obviating proper SOI response] diminishes, a strongly negative NAO will not initiate

 

This is changing.

 

A weakly negative / transient NAO develops later this week, which could play a salutary role in the resolution of the 27-28th winter storm threat; although, it is largely EPO/PNA driven. Usual caveats apply, but it is certainly a threat to monitor, and the most conducive threat to date.

 

The Maritime Continent divergence will finally subside by the end of January. This is evinced quite ostensibly on the chi z200 propagation plots, and the easterly negative trades will subside as well, permitting emergence of more classical walker cell forcing.

 

It's not necessary the MJO itself, but overall divergence has been antithetical to proper +AAM transport through the sub-tropics and consequently negative deposits poleward.

 

Conclusion: The atmospheric pattern has changed and is much colder. The NAM has reversed, but the spasmodic NAO has permitted rainstorms for the East Coast [expected for the last event]. A real negative NAO will finally emerge as tropospheric receptivity increases dramatically by February 1st.

 

Notes and asides: Snowfall timing is the most difficult parameter of a long range forecast. However we get there - we get there. A forecaster should not be penalized for snows not being "evenly spread throughout the winter." If the final tally at the winter's end is close, then it's a good forecast. So, while there's been no snow to date, that will simply have to be dealt with. That doesn't intimate non-emergence prospectively. Key indicators and atmospheric changes were foreseen, and now we will watch the final dominos this week. I have read some comments here and there across the boards that forecasters promised a historic winter, etc., or a historic winter period; I simply want to make clear that those words never emerged from my end. My winter snowfall forecast from November for NYC-area was 37-47". This is still attainable.

 

Tom

Tom thanks for your very lucid analysis.  The way the season has evolved and even though 2012-13 was not a true el nino (we have to get away from being too dependent on ENSO), do you think this season may follow a similar progression?  Bluewave (Chris) and I have been talking about it extensively in the NYC area subforum, that starting with the November snowstorm and continuing with what our area has experienced both temp and snowfall-wise, this season has been a very good match to 2012-13.  Does this mean eastern regions will get a megasnowstorm in February?  Obviously not, but perhaps the risks are higher than they would ordinarily be and if it does happen, I do hope it's a big event for more than just the eastern regions.  In addition to that, we had a significant event in March, so since the whole pattern change was delayed this season just like it was in 2012-13 do you think the chances are now higher that the wintry pattern may continue on into March?  My thinking is yes.

 

[Isotherm]

16 hours ago, 40/70 Benchmark said:

@Isotherm Tom, are you concerned about your DJF seasonal call for a mean neg NAO?

 

No, not yet. The call was for weakly negative DJF NAO, and weakly negative AO as well. December was +0.6 NAO, January will probably average around near neutral, and I'm expecting February will be solidly negative (could average -1 or lower), so that should push the trimonthly average negative. We'll see.

[Isotherm]

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.

 

 

 

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

 

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.

[nzucker]

Tom,

Great thoughts. I also think a major factor in the lack of significant winter weather (aside from the polar vortex and 2F low in NYC) is the location of the +ENSO event. Many were expecting a west-based El Niño/Modoki look like 09-10 or 57-58 (just weaker). That didn't come to pass as the Niño was basin-wide. I think that had a major impact on the lack of Nor'easters and unfavorable MJO pattern as it's largely SSTAs that determine tropical convection cycles, along with AAM as you mentioned.

As the warmth in Region 1.2 has evaporated and cooler SSTs have emerged to the south, we now have a more Modoki look. I wonder if that's the reason for the more favorable pattern showing up on the models.

[40/70 Benchmark]

@Isotherm.....1979-80 is the season that you are referring to. I noted the similarity QBO wise, but dismissed it.

I don't think 1969 was a bad analog, but the blocking just didn't materialize, which is what saved that winter in February.

Thanks.

@raindancewx had the best call that I have seen this season...I'd be interested in his thoughts on this on what you have laid out...

[Isotherm]

1 hour ago, nzucker said:

Tom,

Great thoughts. I also think a major factor in the lack of significant winter weather (aside from the polar vortex and 2F low in NYC) is the location of the +ENSO event. Many were expecting a west-based El Niño/Modoki look like 09-10 or 57-58 (just weaker). That didn't come to pass as the Niño was basin-wide. I think that had a major impact on the lack of Nor'easters and unfavorable MJO pattern as it's largely SSTAs that determine tropical convection cycles, along with AAM as you mentioned.

As the warmth in Region 1.2 has evaporated and cooler SSTs have emerged to the south, we now have a more Modoki look. I wonder if that's the reason for the more favorable pattern showing up on the models.

 

Thanks, Nate. I did see some warning signs in the autumn, but November reversed toward a more high AAM/Nino-esque forcing state, coupled w/ NAO ignition, which tended to countermand my earlier thoughts. Overall, November's ephemeral flux of Nino-esque conditions proved to be a bit of a pretense, and a Nina-esque type forcing regime entered the picture in December. 

 

47 minutes ago, 40/70 Benchmark said:

@Isotherm.....1979-80 is the season that you are referring to. I noted the similarity QBO wise, but dismissed it.

I don't think 1969 was a bad analog, but the blocking just didn't materialize, which is what saved that winter in February.

Thanks.

@raindancewx had the best call that I have seen this season...I'd be interested in his thoughts on this on what you have laid out...

 

Ray, was referring to 2001-02 and 1994-95, the only two years since the late 1970s in which we had a +QBO at the 30mb level and -QBO at the 50mb level. It's something, with the benefit of hindsight, that I did not believe would be deleterious pre-season, but I think it has; of course, among other factors as well, like the basin-wide Nino, the off-equator warmth in the west Pacific enhancing poor MJO phases, the SSW as well, etc. Fortunately, my last winter miss was a long time ago [early part of the decade] and hopefully the next miss won't occur for a long time. Significant lessons derived this year.

[raindancewx]

I think what I said in November more or less held up pretty well. The Fall being completely opposite to 1963-64 held through winter. It was warmer than average in the NE/Plains/MW in December, February is cold in the West to date, and the east is warm to date. The December blend of 2009/2015 for the Plains/NE/MW with Nino 4 SSTs basically matched exactly. If 1963-64 was the guideline, you'd have had a cold NE in Dec and Feb, both look warm, and Feb looks very cold in the West actually, instead of warm like in 1964 (outside NM where it was much colder in 1964). 

It's not that I assign much value to US Temps themselves, I just thought from the temperature differences that 1963-64 must have had a completely different MJO progression than this year. My thinking was that the MJO was in phases 3-4-5-6 at high amplitude in Oct/Nov in 1963 and that's how the US had near record heat, and then it moved into 7-8-1 in December, which is why it was so cold. We were mostly in 1-2-3 or null in Oct/Nov. 

[Isotherm]

1 hour ago, raindancewx said:

I think what I said in November more or less held up pretty well. The Fall being completely opposite to 1963-64 held through winter. It was warmer than average in the NE/Plains/MW in December, February is cold in the West to date, and the east is warm to date. The December blend of 2009/2015 for the Plains/NE/MW with Nino 4 SSTs basically matched exactly. If 1963-64 was the guideline, you'd have had a cold NE in Dec and Feb, both look warm, and Feb looks very cold in the West actually, instead of warm like in 1964 (outside NM where it was much colder in 1964). 

It's not that I assign much value to US Temps themselves, I just thought from the temperature differences that 1963-64 must have had a completely different MJO progression than this year. My thinking was that the MJO was in phases 3-4-5-6 at high amplitude in Oct/Nov in 1963 and that's how the US had near record heat, and then it moved into 7-8-1 in December, which is why it was so cold. We were mostly in 1-2-3 or null in Oct/Nov. 

 

Can you provide a link to your nationwide winter forecast, with departures forecasted Dec, Jan, Feb? I don't recall seeing your formal winter forecast for the country. 

[raindancewx]

I wasn't referring to my forecast, just what I said in here in November when you were talking about 1963 on the first page.

This is what I had - from mid October. For 12/1-2/11, the blend I picked was fairly close outside the SE US, generally within 2F. I put these numbers in the ENSO thread the other day.

Here are some highs for 12/1-2/11 nationally, and what my analogs had in () for the same period. The years I used were 1953-54, 1976-77, 1986-87, 1994-95 (x2), 2006-07

Atlanta - 56.5F (53.5F)

Albuquerque - 47.7F (48.4F)

Boston - 41.6F (39.6F)

Bismarck - 24.3F (25.9F)

Jacksonville - 68.0F (64.9F)

Philadelphia - 44.0F (42.6F)

Seattle - 48.3F (47.7F)

St. Louis - 43.2F (41.1F)

Main issue with my outlook is going to be February. I had the East cold and the West warm. Looks pretty bad right now for that.

https://www.scribd.com/document/390797995/Winter-2018-19-Outlook

 

[40/70 Benchmark]

2 hours ago, raindancewx said:

I think what I said in November more or less held up pretty well. The Fall being completely opposite to 1963-64 held through winter. It was warmer than average in the NE/Plains/MW in December, February is cold in the West to date, and the east is warm to date. The December blend of 2009/2015 for the Plains/NE/MW with Nino 4 SSTs basically matched exactly. If 1963-64 was the guideline, you'd have had a cold NE in Dec and Feb, both look warm, and Feb looks very cold in the West actually, instead of warm like in 1964 (outside NM where it was much colder in 1964). 

It's not that I assign much value to US Temps themselves, I just thought from the temperature differences that 1963-64 must have had a completely different MJO progression than this year. My thinking was that the MJO was in phases 3-4-5-6 at high amplitude in Oct/Nov in 1963 and that's how the US had near record heat, and then it moved into 7-8-1 in December, which is why it was so cold. We were mostly in 1-2-3 or null in Oct/Nov. 

This is the impression that I had...so glad its been cleared up.

Great job for the most part.....I've learned a lot. 

Like I've said before, the misses are what improve forecasting ability, the verifications build confidence.

We need both.

[LibertyBell]

On 2/14/2019 at 12:28 AM, 40/70 Benchmark said:

This is the impression that I had...so glad its been cleared up.

Great job for the most part.....I've learned a lot. 

Like I've said before, the misses are what improve forecasting ability, the verifications build confidence.

We need both.

You weren't bad with using 1968-69 as an analog at all- did you notice that in Jan 1969 Seattle had a big snowfall month? It was just displaced by a month this time around.  Maybe this means we are in for a good March lol.

 

[LibertyBell]

On 2/13/2019 at 9:24 PM, Isotherm said:

 

Thanks, Nate. I did see some warning signs in the autumn, but November reversed toward a more high AAM/Nino-esque forcing state, coupled w/ NAO ignition, which tended to countermand my earlier thoughts. Overall, November's ephemeral flux of Nino-esque conditions proved to be a bit of a pretense, and a Nina-esque type forcing regime entered the picture in December. 

 

 

Ray, was referring to 2001-02 and 1994-95, the only two years since the late 1970s in which we had a +QBO at the 30mb level and -QBO at the 50mb level. It's something, with the benefit of hindsight, that I did not believe would be deleterious pre-season, but I think it has; of course, among other factors as well, like the basin-wide Nino, the off-equator warmth in the west Pacific enhancing poor MJO phases, the SSW as well, etc. Fortunately, my last winter miss was a long time ago [early part of the decade] and hopefully the next miss won't occur for a long time. Significant lessons derived this year.

How do you feel about the idea that we are headed towards a sustained period of +NAO winters (and when we do have a -NAO it will be the ineffective east-based variety)?