40/70 Benchmark

Yea, its sucks....we are due for a decent December.

https://easternmassweather.blogspot.com/2022/10/growing-consensus-current-enso.html

https://easternmassweather.blogspot.com/2022/10/growing-consensus-current-enso.html

More of a neon light follow request than substance of ultimate relevance.

https://easternmassweather.blogspot.com/2022/10/growing-consensus-current-enso.html Growing Consensus & Current ENSO Evolution Bolster Forecast Confidence Heading Into Winter La Nina Nearing Peak The prevailing theme throughout this past summer and into boreal autumn was that the on-going multiyear cool ENSO event had stagnated, and that continues to be the case here in the latter third of the month of October. In fact, the only reach change in the character of this particular la Nina since August is that it is now an eastward leaning basin-wide event, as opposed to westward leaning, since the coolest anomalies have shifted from the western half to the eastern half. This is evidenced by the both the latest visual plot, which now has the deepest blue (coolest) anomalies centered over the eastern half of the ENSO domain, encompassing regions 3 and 1.2: And the latest tabular weekly data as of October 12th, which has the anomaly on the eastern flank of region 1.2 measured at a very robust -2.0 degrees. 14SEP2022 19.9-0.8 24.1-0.8 25.7-0.9 27.7-0.9 21SEP2022 19.7-1.0 24.1-0.8 25.8-0.9 27.7-1.0 28SEP2022 19.0-1.7 23.9-1.0 25.8-0.8 27.6-1.1 05OCT2022 19.2-1.6 24.0-0.9 25.9-0.8 27.5-1.2 12OCT2022 18.9-2.0 24.0-1.0 25.9-0.8 27.5-1.1 Although this is a relatively subtle change that will not alter the overall designation of this la nina as a basin-wide, hybrid event, it could potentially have some significant ramifications on the seasonal forecast. This is due to the fact that variance amongst the this particular data set is highest of the three respective subgroups, so precise orientation can have a large impact on the ultimate placement of forcing around the hemisphere depending on the state of other major drivers. However, this is a point that transcends the scope of this particular entry and will be discussed more explicitly in the winter outlook. What is of greater relevance within the context of this writing is that the cause of this slight reconfiguration of the anomalies is also the impetus for the impending peak of la nina over the course of the next 5-6 weeks. Note the behavior of the H85 zonal wind anomalies across the ENSO regions in the Hovmoller diagram pictured below. A Hovmoller diagram is a blend of a map and a graph used for plotting meteorological data necessary to track waves. In this case, the wave of focus being the push of easterly trade winds denoted by the color blue. These easterly winds are necessary for the upwelling of the subsurface anomalies to the surface. This is illustrated well by the fact that the two concerted intervals of significant cooling across ENSO region 1.2, the first occurring the week of September 21-28 (-1.0 to -1.7) and the second (-1.6 to -2.0) the week of October 5-12, coincided with and immediately followed the ephemeral advancement of the the upwelling easterly trade winds into this zone. This is denoted by the two circled areas in the annotation above. It is this relationship between the H85mb zonal winds and the subsurface water within the ENSO regions that caused the significant cooling over the eastern regions, and it is this same relationship that is beginning to trigger the peak of la nina in what represents is the very essence of the Walker Cycle, which ensures that ENSO continues to cycle in a state of perpetual self-destruction. Note that back on August 16th, before the easterly trades advanced into the eastern region, the cooler subsurface anomalies had not yet surfaced: But by mid October, after the two intervals of trade wind expansion into region 1.2, the warmer surface anomalies had been eradicated as the cooler subsurface has upwelled. Meanwhile, across the western ENSO zones, the subsurface warmth is intensifying and slowly advancing eastward, meaning that the proximal zone for intensification of la nina is disappearing because subsequent upwelling in these zones will trigger the incipient stages of modoki el nino. The reason being that it is clear that these easterly trade winds are making a concerted retreat back to the west, away from the cool subsurface anomalies to the east, and are also forecast to weaken considerably, which could limit any additional cooling the central region of 3.4. If they do not weaken as much as forecast, although region 3.4 may have one more signifiant round of cooling, this could still be negated by the advance of warmer subsurface waters into the western flank of region 3.4 from region 4. In summary, while it is likely that region 3.4 will have one more burst of cooling over the next one to two weeks following the last gasp of retreating trade winds, the combination of the burgeoning subsurface warmth edging east into region 3.4 and retreating trades moving west through region 3.4 means that the la nina ONI for the SON tri-mothly period is likely to peak within the -1.0 to -1.2 range. This is consistent with the forecast throughout the latter portion of summer and throughout the autumn. This is also consistent with the converging of two camps amongst latest guidance. Guidance Converging on Forecast for SON ONI Peak The October update of the International Research Institute (IRI) suite of guidance is in good agreement with the Eastern Mass Weather forecast SON peak ONI range of anywhere between -1.0 to -1.2C. This is slightly biased towards the more aggressive statistical members (-1.2), as opposed to the more conservative dynamical guidance (-0.89) due to the fact that the current JAS ONI value is already at -0.9 and some slight additional cooling is expected in the wake of the final gasp of trade winds over region 3.4. Additionally, it was mentioned that the la nina has assumed a decidedly more eastward lean as a result of the dual westward expansion of the trades into region 1.2, which is evinced by the current October El Nino Modoki Index of -.92. However, these extreme eastern flank anomalies have peaked and will begin to moderate as a result of the aforementioned retreat of the easterly trades back to the west, which will also entail one last round of cooling over region 3.4. Thus the distribution of the anomalies should begin to centralize more throughout the duration of the autumn and into the winter season, with a mid winter EMI value of approximately -.392 expected during what will be basin-wide la nina with a slight eastward bias. It will be discussed at greater length what this may mean with respect to the ensuing boreal winter season of 2022-2023, but it can definitively be stated that this high confidence ENSO forecast offers further corroboration of a concurrent weather analog composite that seems to be aligning well with observed weather this autumn. Verifying Analog Composite & Looking ahead Indeed, a strong model consensus that is in agreement with the current ENSO forecast, coupled with the fact that the sensible weather cool ENSO analogs seems to be in sync with actual observed weather and forecasts lends itself to above average confidence with respect to the winter forecast at this time. The actual analog years and a full outlook will be issued in early November, but here is a sneak preview at the results thus far this fall, and comparison to model forecasts moving forward. All temperature anomalies will be measured versus the 1951-2010 data set in order to ensure an adequate breadth of time in a quickly changing climate, unless otherwise noted. Actual September 2022: Versus September temperature anomaly analog composite: Actual October 1-19 2022 (only available versus 1991-2020 climo period) Versus October temperature analog composite: Obviously this does not look like a match at this point, however, the forecast for the remainder of October offers hope for an improved verification: Finally, looking ahead, here is the forecast temperature anomaly analog composite for the the month of November, which is again measured against the 1991-2020 climo period only for the purposes of comparison with the forecast period. It will be measured agains the 1951-2010 climo period for the purpose of verification. Versus a recent forecast from the CFS climate model, which has a high degree of accuracy at one month lead time. The winter outlook and attendant specific analog years will continue to be honed until its release in early November-

92-93 wasn't el nino... I wouldn't summarily toss the STJ idea with all of the water vapor released into the atmosphere from the volcano.

My crap is all dead. Moving to raking...

Yea, we will have piggish stretches like that this winter...its not going to be 1996, but it won't be 2012, either.

Agree.

30.4 for the low here.

Good luck with everything, and congrats.

It won't be out for about 2 weeks....I am just referring to my analog composite being on track with a milder October.

I personally feel like the PDO is overrated, anyway.....the PNA, which is what is really important, can be out of sync with it quite often. PNA and EPO are where its at IMHO. PDO is a longer term, multi-decadal signal, like the AMO....its not really as important from a forecasting standpoint.

This la nina is on life support, regardless of how long the SSTs remain below normal. Times, they are a changing.... You guys clean up next year, after a serviceable la nina season this year.

This is good news AFAIC....means everything is on track. I'll do one more update tmw before go-time after Halloween. I'm pretty confident...famous last words...

With urine in the snow on snowman19's lawn

Maybe they forget it was also one of the coldest/snowiest decades in history for the east?

He'd probably write it over about one summer of coc k.

If he starts buying you brews at the GTG, you know whassup.

I was gonna say...that is all you.

There is no question CC is impacting everything, but the issue is that its extraordinarily difficult to assign proper attribution ratios, aside from maybe surface temp.

Well, I think the subsurface does dictate the pattern indirectly speaking due to the fact that it modulates the sea surface given a favorable wind direction to facilitate upwelling....its all one giant feedback, clearly.

While there is undoubtedly CC at play, the impact of weaker ENSO events has always been more diverse and diffuse.

The only SSTs I even mention are ENSO....even the fabled N ATL tripole is overrated IMO....I think its a more worthwhile endeavor to study the subsruface.

The point is many la nina seasons have a latitudinal gradient, so that is not the case.