ENSO Updates (2007 thru 2023)

[NotSparta]

You can tell it's La Niña/cool neutral when this post is dead for an entire week

[StruThiO]

Appears that the longstanding easterly wind burst is initiating another upwelling Kelvin wave:

[Kingarabian]

Also the SOI is finally opening up for a La Nina event, the first time in 3 years. I think come October both the ocean and atmosphere will be primed for a La Nina to completely take over. Cool neutral will continue in the meanwhile.

[StruThiO]

Basin-wide cooling at the surface continues as relentlessly strong trades across nearly the entire Pacific refuse to relax

[St0rmTh0r]

Also the SOI is finally opening up for a La Nina event, the first time in 3 years. I think come October both the ocean and atmosphere will be primed for a La Nina to completely take over. Cool neutral will continue in the meanwhile.

If this happens the season will have a longer peak well into October and November!

[SconnieCane]

Also the SOI is finally opening up for a La Nina event, the first time in 3 years. I think come October both the ocean and atmosphere will be primed for a La Nina to completely take over. Cool neutral will continue in the meanwhile.

If this happens the season will have a longer peak well into October and November!

Hmmmm, I just saw another post elsewhere on this site saying essentially the exact opposite...that a brief 2017-style La Nina was looking more likely.

[toad strangler]

Also the SOI is finally opening up for a La Nina event, the first time in 3 years. I think come October both the ocean and atmosphere will be primed for a La Nina to completely take over. Cool neutral will continue in the meanwhile.

If this happens the season will have a longer peak well into October and November!

Hmmmm, I just saw another post elsewhere on this site saying essential the exact opposite...that a brief 2017-style La Nina was looking more likely.

Yeah I saw that too and disregarded.

[Kingarabian]

Also the SOI is finally opening up for a La Nina event, the first time in 3 years. I think come October both the ocean and atmosphere will be primed for a La Nina to completely take over. Cool neutral will continue in the meanwhile.

If this happens the season will have a longer peak well into October and November!

Hmmmm, I just saw another post elsewhere on this site saying essentially the exact opposite...that a brief 2017-style La Nina was looking more likely.

2017's event was a complete La Nina that lasted from September 2017 through April 2018. 2005's event started later. I think maybe a mixture of the two. I believe cool neutral conditions will be present for the most of the season, similar to 2005 and 2017.

[StruThiO]

Massive trade burst underway:

[NDG]

Big cool down last week.

Nino 1+2 at -1.1C
Nino 3 at -0.7C
Nino 3.4 at -0.8C
Nino 4 at -0.4C

[cycloneye]

https://www.cpc.ncep.noaa.gov/products/ ... ts-web.pdf

[StruThiO]

ONI for MJJ was -0.2C..

[Kingarabian]

We're running cooler than 2005 and 2017 at this point in time. There's is still that small pool of warm anomalies beneath Nino 3 and Nino 1+2 that will help keep ENSO cool-neutral for longer.

[Kingarabian]

Trades will relax over the EPAC and there might be a WWB over the CPAC/east of the dateline. This will slow down the snowball towards a full fledged La Nina that we've seen in the past month, and keep things cool neutral for a little longer.

[NDG]

Central ENSO regions warmed up some last week.
Today's update:

Nino 1+2 down to -1.2C
Nino 3 up to -0.6C
Nino 3.4 up to -0.6C
Nino 4 up to -0.3C

[cycloneye]

EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
13 August 2020

ENSO Alert System Status: La Niña Watch


Synopsis: There is a ~60% chance of La Niña development during Northern Hemisphere fall 2020 and continuing through winter 2020-21 (~55% chance).

By early August 2020, sea surface temperatures (SSTs) were below average in the equatorial Pacific from the Date Line to the west coast of South America [Fig. 1]. The four Niño indices were negative during the latest week, with the Niño-3.4 and Niño-3 indices at -0.6°C [Fig. 2]. Negative equatorial subsurface temperature anomalies (averaged across 180°-100°W), which had weakened during June and early July, began re-strengthening in mid-July [Fig. 3] as below-average subsurface temperatures re-emerged in the east-central equatorial Pacific [Fig. 4]. During July, low-level wind anomalies were easterly across most of the equatorial Pacific, while upper-level wind anomalies were westerly over portions of the far western, central, and eastern Pacific. Tropical convection was suppressed over the western and central Pacific, and was near average over Indonesia [Fig. 5]. Overall, the combined oceanic and atmospheric system remained consistent with ENSO-neutral.

The models in the IRI/CPC plume [Fig. 6] are split between La Niña and ENSO-neutral (Nino-3.4 index between -0.5°C and +0.5°C) during the fall and winter, but slightly favor La Niña from the August-October through the November-January seasons. Based largely on dynamical model guidance, the forecaster consensus favors La Niña development during the August-October season, lasting through winter 2020-21. In summary, there is a ~60% chance of La Niña development during Northern Hemisphere fall 2020 and continuing through winter 2020-21 (~55% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

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

[StruThiO]

Indeed the recent easterly wind stress has generated an upwelling Kelvin wave even stronger than the last.

[StruThiO]

July PDO fell to -0.38. Coolest July since 2013.

[Kingarabian]

Indeed the recent easterly wind stress has generated an upwelling Kelvin wave even stronger than the last.

[url]https://i.imgur.com/omwvm7g.png[url]

Modoki La Nina anyone?

[Kingarabian]

SOI has been in the cool-neutral range of about +4/+6 since July. So the atmospheric coupling is there. Let's see if it can reach the +10/+15 (La Nina) range after the MJO leaves the Pacific.