ENSO Updates (2007 thru 2023)

[NotSparta]

NotSparta, are you using a different climo period than Mike Ventrice is using for the 850mb wind forecasts? The wind speeds look similar in the IO but different in the WPAC (7-9ms vs 10-15ms). Slight discrepancies just curious
https://i.imgur.com/QN1CHK0.png

https://i.imgur.com/GZIkpMe.png

My plots use kts rather than m/s which seems to be the main discrepancy. There are probably some climo differences there as well but don't seem as major. I could change the units if it's causing confusion though

[Kingarabian]

NotSparta, are you using a different climo period than Mike Ventrice is using for the 850mb wind forecasts? The wind speeds look similar in the IO but different in the WPAC (7-9ms vs 10-15ms). Slight discrepancies just curious
https://i.imgur.com/QN1CHK0.png

https://i.imgur.com/GZIkpMe.png

My plots use kts rather than m/s which seems to be the main discrepancy. There are probably some climo differences there as well but don't seem as major. I could change the units if it's causing confusion though

Up to you, it's fine by me the way it is was just wondering.

[Kingarabian]

The warm subsurface pool still resembles a series of downwelling Kelvin waves. But the strength of the mean anomalies is beginning to level off and the thermocline will begin to push back.

For the last 10 days, the current WWB has been weak at best from 140E-160E. Currently, it's not going to be strong enough to trigger another downwelling KW IMO. Without at least some moderate westerly anomalies, and the MJO poised to enter the suppressed phase over the Pacific in about two weeks, there's a good chance for a timely upwelling KW when July starts, which will open the door to cool-neutral ENSO for ASO.

In the meantime, the Nino regions will continue their slow warming trend.

Late next week the GFS tries to set off a potent WWB in relation to a low latitude WPAC system:





There's CFS and mild CMC/Euro support for this setup.

[JetFuel_SE]

CPC May update has ended La Niña and Neutral conditions will prevail thru the fall with La Niña going up in % by the last months of the year. El Niño is with only 8% by ASO.

https://www.cpc.ncep.noaa.gov/products/ ... disc.shtml

https://i.imgur.com/ocQ9fFt.png

Now the Mid-May CPC gives 31% of La Nina by OND and 21% for El Niño conditions by ASO. Neutral conditions dominate 55% for ASO.

https://iri.columbia.edu/wp-content/uploads/2021/05/figure3.png

https://iri.columbia.edu/our-expertise/ ... -iri_plume

You know those mid-month updates almost always have higher El Niño chances than the early-month, right?
Those graphics are just model data without any human curation, which can lead to model biases showing more.

[Kingarabian]

GFS and Canadian don't agree with this 850mb wind setup but it will be hard to get another downwelling KW if this verifies:

[Kingarabian]

The buoys finally might be picking up on some upwelling. The cooler anomalies are kinda too deep to make a quick immediate impact if any (located 150 meters in the WPAC vs your typical 75-125 meters in the EPAC), but it'll be interesting to see if they can migrate to the EPAC and disrupt the surface temperatures warming. Relaxed EPAC trades should keep subsurface anomalies warm in that region throughout June, but maybe a uptick of trades in the WPAC will produce a more traditional upwelling KW.



2011:

[Kingarabian]

June Euro seasonal has La Nina coming back in the fall with Nino 3.4 dropping back to negative during SON:

[Kingarabian]

CPC still has Nino 3.4 rather cool @ -0.2C and OHC beginning to drop:


BOM has Nino 3.4 in positive territory now

Nino 4 and Nino 1+2 remain largely the same. CDAS picking up on some abrupt warming over Nino 3.4 and Nino 3:




Other than a week of above average trades near the dateline, it looks like we will be entering an extended period of below average trades over the CPAC and EPAC. This should continue/maintain the warming that's currently happening.

[DorkyMcDorkface]

Worth seeing how much further the ENSO regions warm before all of this kicks in:

 https://twitter.com/TylerJStanfield/status/1401556840798896134



 https://twitter.com/TylerJStanfield/status/1401556848856215553



 https://twitter.com/TylerJStanfield/status/1401556856661757953

[cycloneye]

That is a very informative thread and an important one that explains in detail all about what is going on and what to expect in the next few months.

[Kingarabian]

Worth seeing how much further the ENSO regions warm before all of this kicks in:

[url]https://twitter.com/TylerJStanfield/status/1401556840798896134[url]
[url]https://twitter.com/TylerJStanfield/status/1401556848856215553[url]
[url]https://twitter.com/TylerJStanfield/status/1401556856661757953[url]

Yeah spot on. There's nothing to disagree with here. Key things is to watch the subsurface and how much it cools, and the surface temperatures and how much those warm.

Blue contours on this CFS hovmoller displays the CCKWs role in stunting the suppressed phase of the MJO and decreasing the odds of -ENSO for July.

[cycloneye]

BoM goes down to Weak La Niña on ASO but is the only model that does that in those months.

http://www.bom.gov.au/climate/enso/#tabs=Overview

[Kingarabian]

Not saying it's going to happen but it's something to look out for. 2006 and 2009 are examples of years that ended up as +ENSO events despite no strong MJO amplification over the WPAC. Strong WPAC MJO amplification usually precede El Nino onsets. But per RMM in those years, the MJO spent a good amount of time over phase 7 and phase 8 in moderate to weak strength. Not saying it's going to happen again, but RMM charts have been showing the MJO signal spending more time over phases 7 and 8 probably due to successive CCKW's moving across the Pacific. Regardless, when ENSO is in neutral it's pretty fragile and small shifts in available forcing can affect it. Still a tough ask as Climo favors cool ENSO after a moderate strength La Nina.

2006:



2009:


2021 so far:

[GrayLancer18]

JetFuel_SE is right, there is a huge discrepancy between CPC reports in the beginning and middle of the month. The ones released at the beginning of the month are more analyzed than mid-month.

Still, the chances of La Niña have gone down slightly a bit compared with the one in early May but there's no call for an El Niño.



 https://twitter.com/philklotzbach/status/1403084067629842432

[Kingarabian]

JetFuel_SE is right, there is a huge discrepancy between CPC reports in the beginning and middle of the month. The ones released at the beginning of the month are more analyzed than mid-month.

Still, the chances of La Niña have gone down slightly a bit compared with the one in early May but there's no call for an El Niño.



[url]https://twitter.com/philklotzbach/status/1403084067629842432[url]

El Nino this year is very unlikely. The discrepancy with this graph is that the neutral bar appears to consist of anything between -0.5C/+0.5C. Something close to -0.5C could mean anything from an above average to a hyperactive Atlantic hurricane season. Something closer to +0.5C could mean a slower Atlantic hurricane season, especially if local variables there do not improve.

[Kingarabian]

CPAC Upwelling KW is more noticeable on the higher resolution subsurface graphics:



To quickly reverse back to -ENSO, upwelling needs to intensify at a good clip moving forward because there's still a noticeable stream of subsurface warm anomalies moving from the WPAC to the CPAC. Easy to see on the sea level anomaly graphics. Upwelling should continue though, as climo favors stronger trades during the summertime when there isn't a decent El Nino base state.

[Kingarabian]

BOM has Nino 3.4 up to +0.2C.

[Kingarabian]

CPC has all regions except for Nino 4 at 0.0C. Nino 4 is at -0.1C.

[Kingarabian]

This hovmoller from 2017 showed how the reversal from +ENSO to -ENSO quickly happened in time for August. Easterlies dominated not just the dateline but also 140E-160E (throughout spring 2017), essentially cutting off the transfer of warm anomalies from the WPAC to the EPAC. There was very little downwelling KW activity in 2017 so the subsurface had no resistance.


A transition to -ENSO in time for August is very possible but I'm not sure how great 2017 ENSO is of an analog for 2021 due to the lack of similarities at the subsurface. Even the 850mb wind profile is different. Since late February through the end of May, there has been WWB's over or near 150E which has allowed the subsurface to remain significantly warmer then 2017.


Although 2011 had similar downwelling KW activity, easterlies were much stronger in March-June over and east of the dateline compared to 2021. Even stronger than 2017s March-May. But to this point, 2011's subsurface looks to be a nice match:

[cycloneye]

Cool Neutral from September.

 https://twitter.com/climatesociety/status/1405590640096854020