ENSO Updates (2007 thru 2023)

[weeniepatrol]

[Category5Kaiju]

https://i.imgur.com/t4DkMpS.png

Yeah at this point I am pretty sure that it is inevitable that we will reach neutral by the AMJ or so timeframe. This is very common I would think for years right after the year a moderate La Nina takes form; some examples of what 2021 (at least analog-wise) could potentially be like are 2008, 2011, 2012, and 2017. Typically a La Nina remaining moderate or strong without much weakening for multiple consecutive years is very rare (the 1998-2000 La Nina is an example of this); however, what we are seeing right now with the Nina weakening I would think is not abnormal

[Kingarabian]

This past week, CDAS is picking up on some pronounced warming over the entire Nino regions:


Buoys as well:


This is likely due to the prolonged weakened trades over the EPAC, and a lack of upwelling kelvin waves from the WPAC.

[cycloneye]

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.

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

[tolakram]

Still waiting for late May. I think it's fair to say we still have no idea.

[cycloneye]

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

[Kingarabian]

The CFS continues to show a WWB over the WPAC that moves into the CPAC. Kicks it off around the first week of April. It coincides with a future strong MJO active phase. Time will tell if this is going to occur but it has been showing this for the past month.

[Kingarabian]

OHC positive for the first time in nearly a year:

[cycloneye]

OHC positive for the first time in nearly a year:
https://i.imgur.com/LV2RIgn.png

That has been a almost vertical warmup.

[Category5Kaiju]

OHC positive for the first time in nearly a year:
https://i.imgur.com/LV2RIgn.png

So does this mean we're about to get an El Nino? I'm actually a bit confused

[DorkyMcDorkface]

OHC positive for the first time in nearly a year:
https://i.imgur.com/LV2RIgn.png

So does this mean we're about to get an El Nino? I'm actually a bit confused

It's likely going to take a lot for a complete reversal to El Niño atmospherically a la 2006 (and even then you have to consider 2020-21's La Niña event has been far stronger than 2005-06's, which barely even qualified as La Niña, more like neutral if anything). In the (relatively) short term it does look like we'll be getting some constructive interference partially influenced by the MJO that may help steady the ship a bit from the lapse we saw from mid-February to earlier this month by enhancing trades in the Central Pacific once again (although we'll see if the CFS verifies in the long-term as Kingarabian mentioned).





I think another factor that people don't mention much is the the African Standing Wave. With how potent it has been in recent years it has seemingly played a role in influencing +ENSO development over the past few years. For example, both 2018-19 and 2019-20 were very weak El Niños that did not develop until the winter, which perhaps could partially be attributed to the ASW being the dominant atmospheric feature globally (also explains why both years ended up active in the Atlantic despite less-than-optimal conditions otherwise). If the standing wave comes roaring back yet again it's likely we won't see much more in the way of deviation from the current pattern, Pacific included. I feel that right now the most likely scenario would be a rise to cool-neutral over the summer with a dip back to La Niña in the fall/winter (essentially the same forecast as the CPC).

[Kingarabian]

OHC positive for the first time in nearly a year:
https://i.imgur.com/LV2RIgn.png

So does this mean we're about to get an El Nino? I'm actually a bit confused

No it just means that the ocean subsurface is back into neutral territory. It just gives you an idea of where things are for the ocean component of ENSO.

[Kingarabian]

OHC positive for the first time in nearly a year:
https://i.imgur.com/LV2RIgn.png

So does this mean we're about to get an El Nino? I'm actually a bit confused

It's likely going to take a lot for a complete reversal to El Niño atmospherically a la 2006 (and even then you have to consider 2020-21's La Niña event has been far stronger than 2005-06's, which barely even qualified as La Niña, more like neutral if anything). In the (relatively) short term it does look like we'll be getting some constructive interference partially influenced by the MJO that may help steady the ship a bit from the lapse we saw from mid-February to earlier this month by enhancing trades in the Central Pacific once again (although we'll see if the CFS verifies in the long-term as Kingarabian mentioned).
[url]https://i.ibb.co/Rb2NHV0/vp-anom-30-5-S-5-N.gif[url]
[url]https://i.ibb.co/qY0S8tV/gfs-0-N-hov-uanom-2021031818.pngf[url]
[url]https://i.ibb.co/cDrt4Yv/eps-chi200-anomaly-hov-equatorial-2021031812-MEAN.png[url]
[url]https://i.ibb.co/s9n3JHQ/eps-u850-anom-hov-equatorial-2021031812.png[url]

I think another factor that people don't mention much is the the African Standing Wave. With how potent it has been in recent years it has seemingly played a role in influencing +ENSO development over the past few years. For example, both 2018-19 and 2019-20 were very weak El Niños that did not develop until the winter, which perhaps could partially be attributed to the ASW being the dominant atmospheric feature globally (also explains why both years ended up active in the Atlantic despite less-than-optimal conditions otherwise). If the standing wave comes roaring back yet again it's likely we won't see much more in the way of deviation from the current pattern, Pacific included. I feel that right now the most likely scenario would be a rise to cool-neutral over the summer with a dip back to La Niña in the fall/winter (essentially the same forecast as the CPC).

I agree with all your points here. The best bet has to cool-neutral followed by a La Nina resurgence. Hard to argue with climo here. Especially since we saw what happened in 2012 and 2017.

Next 2 months will be important though because the CFS and Euro show the MJO becoming active/strong over the WPAC and then CPAC, with the CFS showing a month long WWB in those regions. This is not what happened in 2017, where the trades remained in full command throughout the spring.

[Category5Kaiju]

So does this mean we're about to get an El Nino? I'm actually a bit confused

It's likely going to take a lot for a complete reversal to El Niño atmospherically a la 2006 (and even then you have to consider 2020-21's La Niña event has been far stronger than 2005-06's, which barely even qualified as La Niña, more like neutral if anything). In the (relatively) short term it does look like we'll be getting some constructive interference partially influenced by the MJO that may help steady the ship a bit from the lapse we saw from mid-February to earlier this month by enhancing trades in the Central Pacific once again (although we'll see if the CFS verifies in the long-term as Kingarabian mentioned).
[url]https://i.ibb.co/Rb2NHV0/vp-anom-30-5-S-5-N.gif[url]
[url]https://i.ibb.co/qY0S8tV/gfs-0-N-hov-uanom-2021031818.pngf[url]
[url]https://i.ibb.co/cDrt4Yv/eps-chi200-anomaly-hov-equatorial-2021031812-MEAN.png[url]
[url]https://i.ibb.co/s9n3JHQ/eps-u850-anom-hov-equatorial-2021031812.png[url]

I think another factor that people don't mention much is the the African Standing Wave. With how potent it has been in recent years it has seemingly played a role in influencing +ENSO development over the past few years. For example, both 2018-19 and 2019-20 were very weak El Niños that did not develop until the winter, which perhaps could partially be attributed to the ASW being the dominant atmospheric feature globally (also explains why both years ended up active in the Atlantic despite less-than-optimal conditions otherwise). If the standing wave comes roaring back yet again it's likely we won't see much more in the way of deviation from the current pattern, Pacific included. I feel that right now the most likely scenario would be a rise to cool-neutral over the summer with a dip back to La Niña in the fall/winter (essentially the same forecast as the CPC).

I agree with all your points here. The best bet has to cool-neutral followed by a La Nina resurgence. Hard to argue with climo here. Especially since we saw what happened in 2012 and 2017.

Next 2 months will be important though because the CFS and Euro show the MJO becoming active/strong over the WPAC and then CPAC, with the CFS showing a month long WWB in those regions. This is not what happened in 2017, where the trades remained in full command throughout the spring.

Yeah, I am inclined to believe the same. Historically speaking, I am simply not 100% sure if there was ever a time an El Niño developed the year right after a moderate La Niña did, so I’d have to imagine the base state would still favor a cool pattern. I am inclined to think that 2008, 2012, and 2017 would be some analog years we could look at, but if the CFS’s WWB verified, I wonder whether that will simple make neutral more likely or if it really could do the unexpected and allow for a complete reversal toward El Niño

[weeniepatrol]

Warm anomalies emerging now. This nina is toast

[DorkyMcDorkface]

Regardless of what happens this year I think we may be in a good position for an El Niño event of some sort in 2022...
 https://twitter.com/PaulRoundy1/status/1372904993334919179

[Category5Kaiju]

Regardless of what happens this year I think we may be in a good position for an El Niño event of some sort in 2022...
https://twitter.com/PaulRoundy1/status/1372904993334919179

Yeah tbh I personally think if an El Nino were to form it'd be at the earliest next year. I'd actually be very surprised if an El Nino occurred this year, I think it's still a little bit early for all that warm water to actually have an effect.

[Kingarabian]

This is purely speculation. The 90 day CFS is also killing off the Nina standing wave over the dateline by June. The dashed contour lines (sinking motion) decrease to 1 and then starts shifting away from the dateline during the first week of June. Solid contour lines (rising motion) start moving over the dateline.


Now for some 2017 perspective:

The CFS famously called for an April-May WWB back in 2017 that DID NOT materialize:
 https://twitter.com/philklotzbach/status/853935460854509568




This Euro 850mb wind hovmoller clearly shows no WWB for that time frame.
 https://twitter.com/MJVentrice/status/860127404676837376





A big difference comparing 2021 to 2017 is that in the spring of 2017, there were actually no downwelling Kelvin waves:

Mike Ventrice tweeted this in 2017:
 https://twitter.com/MJVentrice/status/855140403674271744




For what it's worth, that's clearly not the case this year:





It's crazy how warm the Nino regions got in 2017 despite very little WWB and DW Kelvin wave support:


Just some things to keep in mind since April is right around the corner.

[aspen]

This is purely speculation. The 90 day CFS is also killing off the Nina standing wave over the dateline by June. The dashed contour lines (sinking motion) decrease to 1 and then starts shifting away from the dateline during the first week of June. Solid contour lines (rising motion) start moving over the dateline.
https://i.imgur.com/dr2tuLd.png

Now for some 2017 perspective:

The CFS famously called for an April-May WWB back in 2017 that DID NOT materialize:
https://twitter.com/philklotzbach/status/853935460854509568

This Euro 850mb wind hovmoller clearly shows no WWB for that time frame.
https://twitter.com/MJVentrice/status/860127404676837376


A big difference comparing 2021 to 2017 is that in the spring of 2017, there were actually no downwelling Kelvin waves:

Mike Ventrice tweeted this in 2017:
https://twitter.com/MJVentrice/status/855140403674271744

For what it's worth, that's clearly not the case this year:
https://i.imgur.com/kd0dCSp.png

https://i.imgur.com/3XQVB7p.png


It's crazy how warm the Nino regions got in 2017 despite very little WWB and DW Kelvin wave support:
https://i.imgur.com/W5qVuBL.png

Just some things to keep in mind since April is right around the corner.

So if I’m reading this right, 2021 and 2017 are having similar beats in terms of ENSO transition, but 2017 had more things suggesting an El Niño.

Please correct me if I got this wrong.

[Kingarabian]

This is purely speculation. The 90 day CFS is also killing off the Nina standing wave over the dateline by June. The dashed contour lines (sinking motion) decrease to 1 and then starts shifting away from the dateline during the first week of June. Solid contour lines (rising motion) start moving over the dateline.
https://i.imgur.com/dr2tuLd.png

Now for some 2017 perspective:

The CFS famously called for an April-May WWB back in 2017 that DID NOT materialize:
https://twitter.com/philklotzbach/status/853935460854509568

This Euro 850mb wind hovmoller clearly shows no WWB for that time frame.
https://twitter.com/MJVentrice/status/860127404676837376


A big difference comparing 2021 to 2017 is that in the spring of 2017, there were actually no downwelling Kelvin waves:

Mike Ventrice tweeted this in 2017:
https://twitter.com/MJVentrice/status/855140403674271744

For what it's worth, that's clearly not the case this year:
https://i.imgur.com/kd0dCSp.png

https://i.imgur.com/3XQVB7p.png


It's crazy how warm the Nino regions got in 2017 despite very little WWB and DW Kelvin wave support:
https://i.imgur.com/W5qVuBL.png

Just some things to keep in mind since April is right around the corner.

So if I’m reading this right, 2021 and 2017 are having similar beats in terms of ENSO transition, but 2017 had more things suggesting an El Niño.

Please correct me if I got this wrong.

Opposite. 2017 actually had nothing going for it but we still saw warm Nino regions. 2021 has a clear ocean subsurface advantage. The real question is whether the winds will shift more westerly to allow this warm subsurface water to breach the surface.