Support the Arctic Sea Ice Forum and Blog

Author Topic: 2021 ENSO  (Read 2894 times)

gerontocrat

  • Multi-year ice
  • Posts: 12025
    • View Profile
  • Liked: 4149
  • Likes Given: 32
2021 ENSO
« on: February 11, 2021, 03:39:26 PM »
late on parade starting this new topic.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml
Quote
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
11 February 2021
 
ENSO Alert System Status: La Niña Advisory

Synopsis:  There is a ~60% chance of a transition from La Niña to ENSO-Neutral during the Northern Hemisphere spring 2021 (April-June).

La Niña persisted in January, reflected by below-average sea surface temperatures (SST) anomalies extending from the western to east-central Pacific Ocean [Fig. 1]. SSTs returned to near average in the eastern Pacific Ocean by the end of the month, as indicated by the latest weekly Niño-3 and Niño-1+2 index values of -0.3°C and -0.2°C, respectively [Fig. 2]. However, the latest weekly Niño index values in the central (Niño-4) and east-central (Niño-3.4) Pacific Ocean were -1.1°C and -0.7°C. The below-average SSTs were supported by negative subsurface temperature anomalies [Fig. 3], which extended from the surface to at least ~150m below the surface between 160°E and 130°W [Fig. 4]. Low-level wind anomalies remained easterly from the western to east-central (~140°W) tropical Pacific, with the largest amplitude near the Date Line. Upper-level wind anomalies were westerly across most of the tropical Pacific. Tropical convection continued to be suppressed over the western and central Pacific and enhanced around the Philippines and Indonesia [Fig. 5], while both the Southern Oscillation and Equatorial Southern Oscillation remained positive. Overall, the coupled ocean-atmosphere system remains consistent with La Niña.

Most of the models in the IRI/CPC plume predict a transition to ENSO-neutral during the Northern Hemisphere spring 2021 [Fig. 6]. The forecaster consensus is in agreement with this transition and then predicts a continuation of ENSO-neutral at least through the Northern Hemisphere summer. In part, due to the inherent uncertainty in predictions made at this time of year, the forecast for the fall remains split (~50%) between La Niña and the combination of the other two possibilities (El Niño and Neutral). In summary, there is a ~60% chance of a transition from La Niña to ENSO-Neutral during the Northern Hemisphere spring 2021 (April-June; click CPC/IRI consensus forecast for the chances in each 3-month period).

La Niña is anticipated to affect climate across the United States during the upcoming months. The 3-month seasonal temperature and precipitation outlooks will be updated on Thursday February 18th.

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 11 March 2021.

To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

 
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740[/size]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Tom_Mazanec

  • Guest
Re: 2021 ENSO
« Reply #1 on: February 11, 2021, 05:16:18 PM »
So at least one forecast gives a moderate El Nino by summer?

Rodius

  • Grease ice
  • Posts: 729
    • View Profile
  • Liked: 388
  • Likes Given: 23
Re: 2021 ENSO
« Reply #2 on: February 12, 2021, 03:56:27 AM »
I wish there were more La Nina events, the weather in Melbourne this summer has excluded heatwave and extra heat. It has been great summer..... shame it wont happen next summer and I dread the next El Nino.

grixm

  • Grease ice
  • Posts: 509
    • View Profile
  • Liked: 263
  • Likes Given: 93
Re: 2021 ENSO
« Reply #3 on: March 09, 2021, 11:03:46 PM »
Niño 3.4 jumped a bit last week and is now warmer than it has been for quite a while.


gerontocrat

  • Multi-year ice
  • Posts: 12025
    • View Profile
  • Liked: 4149
  • Likes Given: 32
Re: 2021 ENSO
« Reply #4 on: March 11, 2021, 03:16:48 PM »
Quote
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
11 March 2021

ENSO Alert System Status: La Niña Advisory

 
Synopsis:  There is a ~60% chance of a transition from La Niña to ENSO-Neutral during the Northern Hemisphere spring 2021 (April-June).

La Niña continued during February, reflected by below-average sea surface temperatures (SST) anomalies, which extended from the western to east-central Pacific Ocean [Fig. 1]. SSTs returned to near average in the eastern Pacific Ocean by late January, before oscillating during February, as indicated by the week-to-week variability in most of the Niño index regions [Fig. 2]. The latest weekly Niño index values in the central (Niño-4) and east-central (Niño-3.4) Pacific Ocean were -0.8°C and -0.7°C. The below-average SSTs were linked to negative subsurface temperature anomalies [Fig. 3], which weakened noticeably during the month. Currently, negative subsurface anomalies extended from the surface to approximately ~150m below the surface between 150°E and 90°W [Fig. 4]. Low-level wind anomalies showed periods of enhanced, but localized, easterlies in the east-central Pacific. Upper-level wind anomalies were westerly across the central and eastern tropical Pacific. The suppression of tropical convection over the western and central Pacific weakened during February, as did the enhancement of rainfall around the Philippines and Indonesia [Fig. 5] compared to the previous few months. The Southern Oscillation and Equatorial Southern Oscillation remained positive, but also weakened. Overall, the coupled ocean-atmosphere system is consistent with a weak or decaying La Niña.

Most of the models in the IRI/CPC plume predict a transition to ENSO-neutral during the Northern Hemisphere spring 2021 [Fig. 6]. The forecaster consensus agrees with this transition and then predicts a continuation of ENSO-neutral at least through the Northern Hemisphere summer. In part, due to the uncertainty in predictions made at this time of year, the forecast for September-November remains lower confidence with a 45-50% for La Niña and 40-45% for ENSO-Neutral, with a low chance for El Niño. In summary, there is a ~60% chance of a transition from La Niña to ENSO-Neutral during the Northern Hemisphere spring 2021 (April-June; click CPC/IRI consensus forecast for the chances in each 3-month period).

La Niña is anticipated to affect climate across the United States during the upcoming months. The 3-month seasonal temperature and precipitation outlooks will be updated on Thursday March 18th.

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 8 April 2021.

To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

 
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740[/size]

click images to enlarge
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

grixm

  • Grease ice
  • Posts: 509
    • View Profile
  • Liked: 263
  • Likes Given: 93
Re: 2021 ENSO
« Reply #5 on: March 28, 2021, 10:31:06 AM »
Daily values have now been in the ENSO Neutral range for over three weeks.

(This doesn't mean we don't still have La Niña, but it's likely the beginning of the end.)

Jim Hunt

  • First-year ice
  • Posts: 5196
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 625
  • Likes Given: 56
Re: 2021 ENSO
« Reply #6 on: March 30, 2021, 05:09:33 PM »
(This doesn't mean we don't still have La Niña, but it's likely the beginning of the end.)

According to today's BoM ENSO outlook:

Quote
The 2020−21 La Niña has ended, having been active since September 2020. The tropical Pacific Ocean has returned to near-normal temperatures, in line with the typical El Niño / La Niña life-cycle. Most model outlooks suggest a neutral El Niño-Southern Oscillation (ENSO) state (neither El Niño nor La Niña) is the most likely scenario through the remainder of the southern hemisphere autumn and winter.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

gerontocrat

  • Multi-year ice
  • Posts: 12025
    • View Profile
  • Liked: 4149
  • Likes Given: 32
Re: 2021 ENSO
« Reply #7 on: April 09, 2021, 10:03:00 AM »
Quote
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
8 April 2021
 
ENSO Alert System Status: La Niña Advisory

 
Synopsis:  A transition from La Niña to ENSO-Neutral is likely in the next month or so, with an 80% chance of ENSO-neutral during May-July 2021.

La Niña continued during March, reflected by negative sea surface temperatures (SST) anomalies, which extended across much of the equatorial Pacific Ocean [Fig. 1]. SST anomalies weakened but continue to oscillate week-to-week in most of the Niño index regions, particularly in the eastern Pacific Ocean [Fig. 2]. Except for Niño-1+2, the latest weekly Niño index values were at or near -0.5°C. Sub-surface ocean temperatures also weakened during the month, with the integrated anomalies averaged between the 180-100°W becoming positive during the middle of the month [Fig. 3]. Currently, negative subsurface temperature anomalies are present from the surface to approximately ~100m below the surface only in the eastern Pacific between 110°W and 80°W [Fig. 4]. Low-level easterly wind anomalies are present but weak across the equatorial Pacific, and are most notable in the far western Pacific. Upper-level wind anomalies were westerly across most of the tropical Pacific. The suppression of tropical convection over the western and central Pacific persisted during March, although the enhancement of rainfall around the Philippines and Indonesia weakened [Fig. 5]. The Southern Oscillation and Equatorial Southern Oscillation were weakly positive in March. Overall, the trend in the coupled ocean-atmosphere system is consistent with a weakening La Niña.

Most of the models in the IRI/CPC plume predict a transition to ENSO-neutral during the Northern Hemisphere spring 2021 [Fig. 6]. The forecaster consensus agrees that a transition is imminent, with a 50-50% chance of La Niña or ENSO-neutral for the March-May average, and then predicts ENSO-neutral to continue at least through the Northern Hemisphere summer. In part, due to the uncertainty in predictions made at this time of year, the forecast for the Northern Hemisphere Fall 2021 has lower confidence with a 40-50% chance of either La Niña or ENSO-Neutral, with a small chance for El Niño. In summary, a transition from La Niña to ENSO-Neutral is likely in the next month or so, with an 80% chance of ENSO-neutral during May-July 2021 (click CPC/IRI consensus forecast for the chances in each 3-month period).

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 13 May 2021.

To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

 
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740
[/size]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

vox_mundi

  • First-year ice
  • Posts: 5699
    • View Profile
  • Liked: 2719
  • Likes Given: 467
Re: 2021 ENSO
« Reply #8 on: April 15, 2021, 06:44:59 PM »
Scientists More Confident Projecting ENSO Changes Under Global Warming
https://phys.org/news/2021-04-scientists-confident-enso-global.html

An international team of scientists from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences, the University of Tokyo, and the University of California, San Diego reported that ENSO-related climate variability seems doomed to increase under global warming. Their findings were published in Nature Geoscience on April 15.

Recently, the climate science community has found that ENSO's changes in fact strictly obey some basic physical mechanisms, which can reduce uncertainty in ENSO projections under greenhouse warming. "The saturation vapor pressure increases exponentially with the increase of temperature, so the same air temperature anomaly will lead to a larger saturation vapor pressure anomaly in a warmer climate," said lead author Dr. Hu Kaiming from IAP. "As a result, under global warming, even if ENSO's sea surface temperature remains unchanged, the response of tropical lower tropospheric humidity to ENSO will amplify, which in turn results in major reorganization of atmospheric temperature, circulation and rainfall."

Based on this mechanism, the team deduced an intensification in ENSO-driven anomalies in tropical humidity, tropical rainfall, upper tropospheric temperature in the tropics, and the subtropical jets under global warming. Almost all the latest CMIP5/6 climate model projections agreed well with the theoretical deduction, indicating the mechanism and projections were robust. "As extreme weather often results from ENSO-induced anomalous atmospheric circulation and temperature, the intensification of ENSO-driven atmospheric variability suggests that the risk of extreme weather will increase in the future," said Dr. Hu.



Intensification of El Niño-induced atmospheric anomalies under greenhouse warming, Nature Geoscience (2021)
https://www.nature.com/articles/s41561-021-00730-3
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

Gray-Wolf

  • Grease ice
  • Posts: 902
    • View Profile
  • Liked: 123
  • Likes Given: 361
Re: 2021 ENSO
« Reply #9 on: April 23, 2021, 02:08:40 PM »
I remember when it was only deep within climate forums that such things as below could be discussed......now it's NOAA blog posts.......


https://www.climate.gov/news-features/blogs/enso/enso-running-fever-or-it-global-warming
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

The Walrus

  • Nilas ice
  • Posts: 1220
    • View Profile
  • Liked: 75
  • Likes Given: 169
Re: 2021 ENSO
« Reply #10 on: May 05, 2021, 10:12:07 PM »
UAH just released their monthly lower tropospheric temperatures.  The current La Nina appears to have a stronger influence than in 2018.

BeeKnees

  • Frazil ice
  • Posts: 447
    • View Profile
  • Liked: 71
  • Likes Given: 97
Re: 2021 ENSO
« Reply #11 on: May 06, 2021, 12:24:37 AM »
Which is to be expected

The Walrus

  • Nilas ice
  • Posts: 1220
    • View Profile
  • Liked: 75
  • Likes Given: 169
Re: 2021 ENSO
« Reply #12 on: May 11, 2021, 07:40:43 PM »
La Nina has certainly affected global temperatures.  Winter 2021 was the eighth warmest, 0.4 C cooler than the record 2016.  The 10 warmest winters are in order:  2016, 2020, 2017, 2019, 2015, 2018, 2010, 2021, 2014, 2013, 2005.  With this relatively cold start to the year, it is hard to see 2021 rise past 6th warmest year on record.  Additionally, the coldest areas when further north; Alaska and Siberia, would bodes well for Arctic sea ice this year.

https://www.ncdc.noaa.gov/sotc/global/202103/supplemental/page-1

kassy

  • Moderator
  • Young ice
  • Posts: 3555
    • View Profile
  • Liked: 1400
  • Likes Given: 1382
Re: 2021 ENSO
« Reply #13 on: May 11, 2021, 08:25:22 PM »
Not too sure about the ice because of all the other things changing but we will see.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

gerontocrat

  • Multi-year ice
  • Posts: 12025
    • View Profile
  • Liked: 4149
  • Likes Given: 32
Re: 2021 ENSO
« Reply #14 on: May 13, 2021, 03:47:27 PM »
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

Goodbye la nina, Hullo neutral

Quote
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION

issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
13 May 2021
 
ENSO Alert System Status: Final La Niña Advisory

 
Synopsis:  La Niña has ended, with ENSO-neutral likely to continue through the Northern Hemisphere summer (67% chance in June-August 2021).

During April, the tropical Pacific Ocean returned to ENSO-neutral conditions as the coupling between the atmosphere and ocean weakened. Sea surface temperatures were near-to-below average across most of the equatorial Pacific Ocean in the past month [Fig. 1]. The Niño indices have generally trended toward normal during the last several months, except for the easternmost Niño-1+2 region, which was -0.7°C in the past week [Fig. 2]. Subsurface temperature anomalies continued to increase [Fig. 3] due to a downwelling Kelvin wave, which reinforced the positive temperature anomalies along the thermocline [Fig. 4]. Low-level easterly wind anomalies were weakly present in the east-central Pacific, but were westerly in the far western Pacific Ocean, while upper-level wind anomalies remained westerly across the central and east-central tropical Pacific. Tropical convection became near average around the Date Line in the past month, with suppressed convection evident over Indonesia [Fig. 5]. Overall, the ocean and atmosphere system reflected a return to ENSO-neutral.

Most of the models in the IRI/CPC plume predict a continuation of ENSO-neutral through the Northern Hemisphere summer 2021 [Fig. 6]. The forecaster consensus agrees with this set of models through the summer, and then begins hedging toward cooler conditions as the Northern Hemisphere fall approaches. La Niña chances are around 50-55% during the late fall and winter, which is in alignment with forecasts from the NCEP Climate Forecast System and North American Multi-model Ensemble. However, there is typically large uncertainty with forecasts made in the spring, so confidence in ENSO-neutral for the coming seasons is highest. In summary, La Niña has ended, with ENSO-neutral likely to continue through the Northern Hemisphere summer (67% chance in June-August 2021; click CPC/IRI consensus forecast for the chances in each 3-month period).

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 10 June 2021.

To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

 
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740
[/size]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Rodius

  • Grease ice
  • Posts: 729
    • View Profile
  • Liked: 388
  • Likes Given: 23
Re: 2021 ENSO
« Reply #15 on: June 25, 2021, 02:18:17 PM »
I am looking at this and wondering if this looks like the beginning of an El Nino.

Lewis

  • New ice
  • Posts: 21
    • View Profile
  • Liked: 7
  • Likes Given: 12
Re: 2021 ENSO
« Reply #16 on: July 09, 2021, 04:07:16 AM »
I am looking at this and wondering if this looks like the beginning of an El Nino.


We are back on La Niña Watch

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

ENSO Alert System Status: La Niña Watch

 
Synopsis:  ENSO-neutral is favored through the Northern Hemisphere summer and into the fall (51% chance for the August-October season), with La Niña potentially emerging during the September-November season and lasting through the 2021-22 winter (66% chance during November-January).

Rodius

  • Grease ice
  • Posts: 729
    • View Profile
  • Liked: 388
  • Likes Given: 23
Re: 2021 ENSO
« Reply #17 on: July 09, 2021, 05:39:00 AM »
I am looking at this and wondering if this looks like the beginning of an El Nino.


We are back on La Niña Watch

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

ENSO Alert System Status: La Niña Watch

 
Synopsis:  ENSO-neutral is favored through the Northern Hemisphere summer and into the fall (51% chance for the August-October season), with La Niña potentially emerging during the September-November season and lasting through the 2021-22 winter (66% chance during November-January).

That would be good. One extra year of favorable conditions.

Sebastian Jones

  • Frazil ice
  • Posts: 482
    • View Profile
  • Liked: 125
  • Likes Given: 111
Re: 2021 ENSO
« Reply #18 on: July 10, 2021, 03:19:11 AM »
I am looking at this and wondering if this looks like the beginning of an El Nino.


We are back on La Niña Watch

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

ENSO Alert System Status: La Niña Watch

 
Synopsis:  ENSO-neutral is favored through the Northern Hemisphere summer and into the fall (51% chance for the August-October season), with La Niña potentially emerging during the September-November season and lasting through the 2021-22 winter (66% chance during November-January).

That would be good. One extra year of favorable conditions.

And one more year of heat building up in the ocean, ready to burst free next El Nino.

Rodius

  • Grease ice
  • Posts: 729
    • View Profile
  • Liked: 388
  • Likes Given: 23
Re: 2021 ENSO
« Reply #19 on: July 10, 2021, 05:45:00 AM »
I am looking at this and wondering if this looks like the beginning of an El Nino.


We are back on La Niña Watch

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

ENSO Alert System Status: La Niña Watch

 
Synopsis:  ENSO-neutral is favored through the Northern Hemisphere summer and into the fall (51% chance for the August-October season), with La Niña potentially emerging during the September-November season and lasting through the 2021-22 winter (66% chance during November-January).

That would be good. One extra year of favorable conditions.

And one more year of heat building up in the ocean, ready to burst free next El Nino.

Every silver lining has a cloud lol

gerontocrat

  • Multi-year ice
  • Posts: 12025
    • View Profile
  • Liked: 4149
  • Likes Given: 32
Re: 2021 ENSO
« Reply #20 on: July 11, 2021, 02:43:12 PM »
Thought I would post the whole notice...

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml
Quote
EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
8 July 2021

ENSO Alert System Status: La Niña Watch

 
Synopsis:  ENSO-neutral is favored through the Northern Hemisphere summer and into the fall (51% chance for the August-October season), with La Niña potentially emerging during the September-November season and lasting through the 2021-22 winter (66% chance during November-January).

Near-average sea surface temperatures, consistent with ENSO-neutral conditions, were observed across most of the equatorial Pacific Ocean during June [Fig. 1]. In the last week, most Niño indices were near zero except for the Niño-1+2 index, which was +0.3°C [Fig. 2]. Subsurface temperature anomalies were slightly positive (averaged from 180-100°W) and remained steady during the month [Fig. 3]. However, in parts of the eastern Pacific, below-average subsurface temperature anomalies returned near the thermocline [Fig. 4]. For the month, the low-level and upper-level winds were near average across most of the equatorial Pacific Ocean. Tropical convection was suppressed near the Date Line, while remaining mostly near average elsewhere [Fig. 5]. Overall, the ocean and atmosphere system reflected ENSO-neutral conditions.

A majority of the models in the IRI/CPC plume predict ENSO-neutral to continue through the fall and winter 2021-22 [Fig. 6]. However, the latest forecast model runs from the NCEP CFSv2, many of the models from the North American Multi-Model Ensemble, and some models from our international partners indicate the onset of La Niña during the Northern Hemisphere fall, continuing into winter 2021-22. The forecaster consensus favors these model ensembles, while also noting the historical tendency for a second winter of La Niña to follow the first. In summary, ENSO-neutral is favored through the Northern Hemisphere summer and into the fall (51% chance for the August-October season), with La Niña potentially emerging during the September-November season and lasting through the 2021-22 winter (66% chance during November-January; click CPC/IRI consensus forecast for the chances in each 3-month period).

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 12 August 2021.

To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

 
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740[/size]
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)