Pattern ENSO Updates

[GaWx]

The weekly for 3.4 issued today was at +0.5 C for the 4th week in a row. The other 3 regions warmed either 0.1 or 0.2.

The SOI has risen into positive territory the last 3 days and should remain mostly positive for the next week or so. However, a sharp drop into negative territory is hinted at by the middle of next week based on a progged large drop in SLP at and all around Tahiti. Let's see if this actually looks to verify as this is a crucial time of year for ENSO.

Followup to the above:

Ever since that one Euro run from this past Monday showing a sharp drop to well below normal SLP's at Tahiti, none have suggested that nor an imminent return to solid -SOI's. We'll likely have an SOI fall during the next couple of days, which MAY dip slightly into -SOI territory, but even if so it then looks to quickly rise back into +SOI territory for the balance of May (at least) IF the latest guidance is correct.

Also, the most recent model guidance for 3.4 has cooled overall, suggesting that IF there is to be El Niño later this year that it would be on the weaker side. Regarding the possibility of a cold SE 2017-8 winter, that chance would be highest based on my research if there is a weak El Niño vs if there is a strong Niño and vs if there is no Niño.

Eric earlier in this thread astutely pointed out that there has since his tables started (in the 1860s as I recall) not been even a single case of an El Niño winter exactly two winters after a superstrong Niño. Are whatever forces that may tend to minimize that chance at work here right now? Perhaps. We'll need to see what happens over the next couple of very crucial months. However, I'll also repeat what I mentioned about this: the sample size of superstrong Ninos is small and the current case of a neutral positive spring the 2nd spring after a superNino is unprecedented (Niño 3.4 was in all other cases neutral negative or colder during the 2nd spring). It is going to be a very interesting next couple of months to follow!

 

[Webberweather53]

Followup to the above:

Ever since that one Euro run from this past Monday showing a sharp drop to well below normal SLP's at Tahiti, none have suggested that nor an imminent return to solid -SOI's. We'll likely have an SOI fall during the next couple of days, which MAY dip slightly into -SOI territory, but even if so it then looks to quickly rise back into +SOI territory for the balance of May (at least) IF the latest guidance is correct.

Also, the most recent model guidance for 3.4 has cooled overall, suggesting that IF there is to be El Niño later this year that it would be on the weaker side. Regarding the possibility of a cold SE 2017-8 winter, that chance would be highest based on my research if there is a weak El Niño vs if there is a strong Niño and vs if there is no Niño.

Eric earlier in this thread astutely pointed out that there has since his tables started (in the 1860s as I recall) not been even a single case of an El Niño winter exactly two winters after a superstrong Niño. Are whatever forces that may tend to minimize that chance at work here right now? Perhaps. We'll need to see what happens over the next couple of very crucial months. However, I'll also repeat what I mentioned about this: the sample size of superstrong Ninos is small and the current case of a neutral positive spring the 2nd spring after a superNino is unprecedented (Niño 3.4 was in all other cases neutral negative or colder during the 2nd spring). It is going to be a very interesting next couple of months to follow!

Very powerful El Nino events tend to reverberate throughout the climate system for several years (or more) following their demise and their alterations to the mean climatic background state are often semi-permanent as we've observed in the satellite record, wherein the upward step changes in global mean temperature have been semi-permanent and subsequent global temperature crashes during NINA events have been considerably feeble and temporary. Wrt the "forces the may" as also noted in the delayed oscillator theory, subsurface wave dynamics control longer term ENSO behavior, while surface wind stress, in particular the meridional width of the wind stress (which is directly proportional to ENSO period at inter annual scales w/ greater meridional breadth = longer ENSO periods and vis versa), as well as the forcing latitude of off-equatorial, westward propagating oceanic Rossby waves also play a significant, but secondary role in long term, inter annual ENSO behavior which is of interest here given that it's been nearly a year and a half since the beginning of the demise of the most recent Super NINO event. ENSO often varies between behaving as a heavily damped oscillator, characterized by long periods and weak ENSO events (as was the case in the mid 20th century), and an unstable, self-sustaining mode that is interlaced with highly amplified, short-lived ENSO events which exhibit rapid, highly volatile growth (as observed near the turn of the 20th and 21st centuries). As far as analogs are concerned, it's important to understand that even with a long 160+ year record that's provided input from a multivariate, ensemble of quality controlled datasets and several adjustments to account for observational, structural, and uncertainty inhomogeneities we're really only seeing one deterministic solution to an innumerable multitude of potential realizations of ENSO behavior, with an appreciably broader spectrum of variability than what's provided by observations alone. Thus, we are still limited in a large sense, but with proper care, doubling the length of record into the mid 19th century is still far superior to a record that uses post-1950 data only. I'm essentially trying to provide backing in the previous few sentences to a premise that the observational record shouldn't be strictly interpreted as a seemingly flawless ultimatum that's incapable of significant deviations from historical precedence, and nor should one implore that these deviations are "very exceptional/unusual" and/or potentially dangerous and henceforth used directly evidence for AGW, only with a succession careful, unbiased modeling and observational studies can a spectrum of such conclusions be derived. Of course, by the time we have "enough" samples to be comparable to ENSO's "true" spectrum of variability, by then the background climatic and observational mean states become increasingly irrelevant, henceforth dynamical underpinnings and modeling studies capable of reproducing thousands of realistic ENSO events with similar mean background states become crucial to the advancement of our reanalysis, understanding, and prediction of ENSO.

In saying this, it's hard to ignore the striking similarities in ENSO behavior between the late 1920s-early 1930s and the last several years. Both periods observed a cool neutral ENSO event (1928-29/2013-14) which was followed by a borderline weak El Nino (1929-30/2014-15), and then a strong-super El Nino (1930-31/2015-16), thereafter, a weak -ENSO event (1931-32/2016-17), and a (presumably) failed attempt at a +ENSO event (1932-33/2017-18 (?))

Ensemble Oceanic Nino Index (ENS ONI) 1929-1932




Ensemble Oceanic Nino Index (ENS ONI) 2014-near present



Again, even with these astounding inter annual similarities, structural, observational, and parametric uncertainties in addition to alterations in the background mean climate as well as contemporary dynamical forcing must be given due consideration.

 

[GaWx]

Interesting similarities to 1929-1932, Eric. So, will we end up with a 1932-3? We shall see! That tells me we should start to see some clearcut cooling in Niño 3.4 by around July to be on a similar track. So, there's still time for that though we may be a little warmer now vs this point in 1932.

Meanwhile, Nino 3.4, which had fallen from +0.5 to +0.4 in last week's update, rose to +0.6 in yesterday's update.

 

[GaWx]

Strictly out of curiosity to come up with some additional guidelines to be used as we see how ENSO progresses this summer, I just did some calcs based on 1981-2016 Darwin/Tahiti monthly SLP's in mb that some may find interesting:

Avg June/July/Aug Darwin SLP minus 1000: 13.0/13.5/13.5
Avg June/July/Aug Tahiti SLP minus 1000: 13.7/14.3/14.6

Avg June/July/Aug Darwin SLP minus 1000 strong Nino: 13.5/14.4/14.6
Avg June/July/Aug Darwin SLP minus 1000 wk-mod Nino: 13.0/13.8/13.7
Avg June/July/Aug Darwin SLP minus 1000 weak Nina: 13.0/13.0/12.8
Avg June/July/Aug Darwin SLP minus 1000 mod-str Nina: 12.8/13.1/12.9

Avg June/July/Aug Tahiti SLP minus 1000 strong Nino: 12.8/13.4/13.6
Avg June/July/Aug Tahiti SLP minus 1000 wk-mod Nino: 13.5/13.9/13.7
Avg June/July/Aug Tahiti SLP minus 1000 weak Nina: 14.2/14.3/15.1
Avg June/July/Aug Tahiti SLP minus 1000 mod-str Nina: 14.1/15.2/15.2

Some analysis of these #'s:

- At Darwin, SLP differences from one ENSO cat. to another are greater in July than June and even greater in Aug. Perhaps this means that in Nino's that avg. Australian sfc highs are stronger and/or extend further north in July/Aug vs June whereas in Nina's they stay about the same through that period?

- At Tahiti, SLP differences from one ENSO cat. to another are much greater in June than the rather narrow range for Darwin. So, perhaps this means that Tahiti is more crucial than Darwin in June. These diffs from one ENSO cat to another rise more in July from June.

- SLP averages higher in Darwin than Tahiti in strong Ninos, they average ~same in weak to mod Ninos, and are clearly higher at Tahiti than Darwin in Ninas. ALL years combined incl neutral ENSO average nearly 1 mb higher at Tahiti than Darwin. This is probably near where neutral years, alone, fall. That is why the SOI is near 0 when Tahiti is ~1 mb higher than Darwin.

- When I refer to ENSO cat., I mean the upcoming fall/winter peak as opposed to where it is during JJA.
----------------------------------------
Monthly SLP data sources:

Darwin monthly SLP (I started with 1981): http://www.cpc.ncep.noaa.gov/data/indices/darwin

Tahiti monthly SLP (I started with 1981):
http://www.cpc.ncep.noaa.gov/data/indices/tahiti

 

[pcbjr]

Strictly out of curiosity to come up with some additional guidelines to be used as we see how ENSO progresses this summer, I just did some calcs based on 1981-2016 Darwin/Tahiti monthly SLP's in mb that some may find interesting:

Avg June/July/Aug Darwin SLP minus 1000: 13.0/13.5/13.5
Avg June/July/Aug Tahiti SLP minus 1000: 13.7/14.3/14.6

Avg June/July/Aug Darwin SLP minus 1000 strong Nino: 13.5/14.4/14.6
Avg June/July/Aug Darwin SLP minus 1000 wk-mod Nino: 13.0/13.8/13.7
Avg June/July/Aug Darwin SLP minus 1000 weak Nina: 13.0/13.0/12.8
Avg June/July/Aug Darwin SLP minus 1000 mod-str Nina: 12.8/13.1/12.9

Avg June/July/Aug Tahiti SLP minus 1000 strong Nino: 12.8/13.4/13.6
Avg June/July/Aug Tahiti SLP minus 1000 wk-mod Nino: 13.5/13.9/13.7
Avg June/July/Aug Tahiti SLP minus 1000 weak Nina: 14.2/14.3/15.1
Avg June/July/Aug Tahiti SLP minus 1000 mod-str Nina: 14.1/15.2/15.2

Some analysis of these #'s:

- At Darwin, SLP differences from one ENSO cat. to another are greater in July than June and even greater in Aug. Perhaps this means that in Nino's that avg. Australian sfc highs are stronger and/or extend further north in July/Aug vs June whereas in Nina's they stay about the same through that period?

- At Tahiti, SLP differences from one ENSO cat. to another are much greater in June than the rather narrow range for Darwin. So, perhaps this means that Tahiti is more crucial than Darwin in June. These diffs from one ENSO cat to another rise more in July from June.

- SLP averages higher in Darwin than Tahiti in strong Ninos, they average ~same in weak to mod Ninos, and are clearly higher at Tahiti than Darwin in Ninas. ALL years combined incl neutral ENSO average nearly 1 mb higher at Tahiti than Darwin. This is probably near where neutral years, alone, fall. That is why the SOI is near 0 when Tahiti is ~1 mb higher than Darwin.

- When I refer to ENSO cat., I mean the upcoming fall/winter peak as opposed to where it is during JJA.
----------------------------------------
Monthly SLP data sources:

Darwin monthly SLP (I started with 1981): http://www.cpc.ncep.noaa.gov/data/indices/darwin

Tahiti monthly SLP (I started with 1981):
http://www.cpc.ncep.noaa.gov/data/indices/tahiti

You just confirmed that by far I'm not the sharpest butter knife in the drawer, Larry! This one has me lost ...

 

[GaWx]

You just confirmed that by far I'm not the sharpest butter knife in the drawer, Larry! This one has me lost ...

The SOI is based on SLP at Tahiti and Darwin in case you don't know. The higher the pressure at Tahiti and the lower the pressure at Darwin, the higher the SOI. +SOI favors stronger easterlies, which favors La Nina development. -SOI favors weaker easterlies or even sometimes westerlies, which favors El Nino development.

 

[pcbjr]

The SOI is based on SLP at Tahiti and Darwin in case you don't know. The higher the pressure at Tahiti and the lower the pressure at Darwin, the higher the SOI. +SOI favors stronger easterlies, which favors La Nina development. -SOI favors weaker easterlies or even sometimes westerlies, which favors El Nino development.

Knew but wasn't following completely!
Thanks Man! I'll be a bit better once they lance this dadgum nerve in my shoulder ....

 

[GaWx]

The SOI is based on SLP at Tahiti and Darwin in case you don't know. The higher the pressure at Tahiti and the lower the pressure at Darwin, the higher the SOI. +SOI favors stronger easterlies, which favors La Nina development. -SOI favors weaker easterlies or even sometimes westerlies, which favors El Nino development.

Further to the above: IF the most recent guidance were to verify well, we could easily see a Darwin June MTD average SLP in the 1013.5 to 1014 mb range through 6/20, which would be pretty El Ninoish based on 1951-present. Not a guarantee by any means but a pretty good lean that way. IF the FULL June were to be at least 1014, it would be a pretty strong Niño signal. Actually, there have been only 3 June's since 1951 in the 1014+ category: 1965, 1997, and 2004. (Highest, which was in 1997, was 1014.7 mb). They went on to be a strong Niño, superstrong Niño, and weak Niño, respectively, by autumn. Something to monitor and could end up being a "canary in a coal mine" kind of advanced signal of El Niño.

 

[pcbjr]

Further to the above: IF the most recent guidance were to verify well, we could easily see a Darwin June MTD average SLP in the 1013.5 to 1014 mb range through 6/20, which would be pretty El Ninoish based on 1951-present. Not a guarantee by any means but a pretty good lean that way. IF the FULL June were to be at least 1014, it would be a pretty strong Niño signal. Actually, there have been only 3 June's since 1951 in the 1014+ category: 1965, 1997, and 2004. (Highest, which was in 1997, was 1014.7 mb). They went on to be a strong Niño, superstrong Niño, and weak Niño, respectively, by autumn. Something to monitor and could end up being a "canary in a coal mine" kind of advanced signal of El Niño.

Thanks for the update!

 

[whatalife]

Ummm...


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[whatalife]

Soooo....I'm going to take it that El Niño isn't coming


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[GaWx]

Soooo....I'm going to take it that El Niño isn't coming

Au contraire, my friend. A weak to low end moderate Modoki Niño is still very much in the cards. Not only is the June SOI projected to be ~-7, which is modestly correlated with El Niño oncoming based on history, but also 3.4 SST's have been slowly rebounding after an early June cooling to +0.4. It looks like June will end up ~+0.5 and the current appears to be ~+0.6. The July SOI is more crucial than June. If it ends up -7 or more neg, the signal for El Niño oncoming will become quite high per history, especially with 3.4 already being near borderline weak Niño levels.
It looks to me last like some of the models that earlier this month significantly cooled fall/winter to neutral from Niño were largely basing that on June cooling off to near +0.2. We'll, that isn't happening at all as I said. Expect to see model consensus warmer in 3.4 in their July progs.

IF there ends up being a Modoki/weakish Niño this fall, look out below tempwise this winter as I have been saying!

By the way, the recent/progged pattern of normal to slightly cooler than norm in the SE is modestly correlated to an oncoming weak Niño. Also, if a weak Niño were to actually materialize, a not so active ASO in the Atlantic tropics would be favored even after a relatively active June as we've had. That will be somewhat tricky as the MDR appears favorably warm at least as of now. So, we'll see.

 

[whatalife]

Au contraire, my friend. A weak to low end moderate Modoki Niño is still very much in the cards. Not only is the June SOI projected to be ~-7, which is modestly correlated with El Niño oncoming based on history, but also 3.4 SST's have been slowly rebounding after an early June cooling to +0.4. It looks like June will end up ~+0.5 and the current appears to be ~+0.6. The July SOI is more crucial than June. If it ends up -7 or more neg, the signal for El Niño oncoming will become quite high per history, especially with 3.4 already being near borderline weak Niño levels.
It looks to me last like some of the models that earlier this month significantly cooled fall/winter to neutral from Niño were largely basing that on June cooling off to near +0.2. We'll, that isn't happening at all as I said. Expect to see model consensus warmer in 3.4 in their July progs.

IF there ends up being a Modoki/weakish Niño this fall, look out below tempwise this winter as I have been saying!

By the way, the recent/progged pattern of normal to slightly cooler than norm in the SE is modestly correlated to an oncoming weak Niño. Also, if a weak Niño were to actually materialize, a not so active ASO in the Atlantic tropics would be favored even after a relatively active June as we've had. That will be somewhat tricky as the MDR appears favorably warm at least as of now. So, we'll see.

Thanks Larry for the update!


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[Webberweather53]

The SOI is probably one of the worst indices to monitor ENSO variability in real-time, and is very susceptible to atmospheric white noise completely unrelated to ENSO even on tri-monthly scales and I strongly caution against its utilization, if anything the tropical atmosphere appears to be behaving more like a La Nina than an El Nino... A moderate El Nino however looks to be moving out of the cards, and there are no signs of a significant downwelling oceanic kelvin wave on the horizon, and given that it takes about 2-3 months for said wave to cross the Eq Pacific and reach the surface over the eastern Pacific, even if a new oceanic KW formed right now and began propagating eastward, it would take until at least September for its effects to be begin to be felt wrt SSTAs. We're running out of time...

 

[Webberweather53]

The SOI is completely disconnected from reality. While current negative values may support an El Nino, the harsh reality is the easterly trade winds are still much stronger than normal over the equatorial Pacific, indicative more so of a La Nina, and the EPS forecast continues to suggest persistence of this regime at least into mid July...

 

[Webberweather53]

IF there ends up being a Modoki/weakish Niño this fall, look out below tempwise this winter as I have been saying!

No, there are a host of other factors at play for the upcoming winter, a weak, modoki NINO will by no means solidify a below normal winter in spite of what history may suggest. Beware of your own confirmation biases for cold/snow and don't fall into the same trap as JB...

By the way, the recent/progged pattern of normal to slightly cooler than norm in the SE is modestly correlated to an oncoming weak Niño. Also, if a weak Niño were to actually materialize, a not so active ASO in the Atlantic tropics would be favored even after a relatively active June as we've had. That will be somewhat tricky as the MDR appears favorably warm at least as of now. So, we'll see.

There's very little support for an inactive hurricane season this upcoming year especially over the east-central MDR, and a weak NINO would do little to stifle it, and again as I mentioned earlier would take until at least September, if not later for the climate system to respond to the Eq Pacific stimulus. Not to mention, the warmer atlantic is actually aiding in fighting off the oncoming El Nino by modulating the local Hadley Cell network and is augmenting the easterly trade winds over the east-central Equatorial Pacific....

 

[Storm5]

Well ok then

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[Storm5]

I find myself wanting to post in this thread but it would be negative towards the upcoming winter so I'll hold off


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[ForsythSnow]

I find myself wanting to post in this thread but it would be negative towards the upcoming winter so I'll hold off


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You've doomed us all now lol . Maybe it won't be so bad in the end, so long as it doesn't end up like last year. After all, there are many other factors that drive the weather, it just makes it harder to get good ones.

 

[Metwannabe]

I find myself wanting to post in this thread but it would be negative towards the upcoming winter so I'll hold off


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I find myself wanting to post in this thread but I don't know what the hell I'm talking about so I'll hold off..... Lol!!