ENSO Updates (2007 thru 2023)

[cycloneye]

Euro may be showing its natural warm bias again but the MEAN looks realistic IMO. The mean favors a warm up to neutral levels and then dipping back negative entering JJA.
https://i.postimg.cc/bwqcFbRK/ezgif-7-b8432b1ccfbe.gif

If this scenario occurs, then an active North Atlantic 2021 season will happen but I dont think it will reach 30 TC's, however it may be hyperactive with 18-20.

[NotSparta]

Euro may be showing its natural warm bias again but the MEAN looks realistic IMO. The mean favors a warm up to neutral levels and then dipping back negative entering JJA.
https://i.postimg.cc/bwqcFbRK/ezgif-7-b8432b1ccfbe.gif

In this scenario of a slowly warming ENSO that peaks at neutral by April-June before starting to cool again, would the atmosphere switch out of a La Niña state, or will a La Niña state (or a similar state) continue without interruption as the ENSO cools off again?

The current SSTA pattern supports a return to neutral, you probably wouldn't need to change the pattern radically to make it neutral during summer. Perhaps a weakening in the atmospheric footprint but I think a slight Niña signal will remain there

[Kingarabian]

Euro may be showing its natural warm bias again but the MEAN looks realistic IMO. The mean favors a warm up to neutral levels and then dipping back negative entering JJA.
https://i.postimg.cc/bwqcFbRK/ezgif-7-b8432b1ccfbe.gif

If this scenario occurs, then an active North Atlantic 2021 season will happen but I dont think it will reach 30 TC's, however it may be hyperactive with 18-20.

You can definitely still have a hyper active North Atlantic hurricane season with a weak La Nina in place. See 2005 for the Atlantic that barely had a weak La Nina in place for ASO, and also see 2018 for the EPAC hurricane season which had a very weak El Nino in place but ended up hyperactive.

[cycloneye]

The cool pool at the subsurface looks to be expanding. Let's see how things evolve in the next few weeks and months.

[Category5Kaiju]

Euro may be showing its natural warm bias again but the MEAN looks realistic IMO. The mean favors a warm up to neutral levels and then dipping back negative entering JJA.
https://i.postimg.cc/bwqcFbRK/ezgif-7-b8432b1ccfbe.gif

If this scenario occurs, then an active North Atlantic 2021 season will happen but I dont think it will reach 30 TC's, however it may be hyperactive with 18-20.

You can definitely still have a hyper active North Atlantic hurricane season with a weak La Nina in place. See 2005 for the Atlantic that barely had a weak La Nina in place for ASO, and also see 2018 for the EPAC hurricane season which had a very weak El Nino in place but ended up hyperactive.

Heck, you can have a hyperactive Atlantic when there is an El Nino in place too! While most El Ninos hinder the overall activity and strength in the Atlantic, 1969 and 2004 are perfect examples that not all El Ninos are the same

[cycloneye]

60% of Neutral by April to June and a slight La Niña uptick by ASO and SON.

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).

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

[Kingarabian]

850mb wind forecasts continue to show stronger than average trades near the dateline and weaker than average trades in the EPAC. ENSO still looks on track to follow 2012/2017.

[Kingarabian]

Could have positive anomalies over Nino 3 and Nino 1+2 by the end of March if this holds up.

[ClarCari]

^

The ENSO is behaving pretty much according to guidance since November which predicted a shift towards at least Cool Neutral by spring. Actually very concerning considering La Niña odds become higher than even neutral odds by summer/fall. Haven’t seen it play any funny tricks thus far,...very unlike the 2006 ENSO

[Kingarabian]

^

The ENSO is behaving pretty much according to guidance since November which predicted a shift towards at least Cool Neutral by spring. Actually very concerning considering La Niña odds become higher than even neutral odds by summer/fall. Haven’t seen it play any funny tricks thus far,...very unlike the 2006 ENSO

I believe it's a very small chance we'll see a 2006 repeat. But going into March, 2006's ocean and wind setup is pretty similar so far to 2021's.


But 2021 also has pretty good similarities with 2012 and 2017.
2006, 2012, 2017, and 2021 all have very common profiles. Cool subsurface pool in the CPAC/EPAC, lack of a traditional dateline WWB, strong trades over the dateline, and below average trades in the EPAC.

[cycloneye]

The weekly CPC update has Niño 3.4 going down to -1.2C.

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

[Kingarabian]

Here's the Euro March update for Nino 3.4:



This update shows more support for warm-neutral for the summer compared to previous months.

This model has a historic warm ENSO bias during the winter and early spring, so I wouldn't think too much of it.

[Kingarabian]

Here are the JJA temperature average from the February and March Euro updates:



http://www.Weathermodels.com

[JetFuel_SE]

Reminder that the SPB is a thing.

[weeniepatrol]

Warm water at depth has expanded in areal extent and magnitude in the wpac (fairly typical la nina response) Need to watch for a downwelling wave and whether or not 850 u-wind anomalies are favorable for its propagation. A 2006-esque scenario is still very much in the cards

[Category5Kaiju]

Warm water at depth has expanded in areal extent and magnitude in the wpac (fairly typical la nina response) Need to watch for a downwelling wave and whether or not 850 u-wind anomalies are favorable for its propagation. A 2006-esque scenario is still very much in the cards

https://i.imgur.com/H9DBEsA.png

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

https://i.imgur.com/2hL10T8.png

I could be wrong and I hope I am, but I simply cannot see a "2006-eque" scenario unfolding since historically speaking, I simply cannot find any example of any recorded time when a moderately strong La Nina took place, only for the subsequent year to feature an El Nino. I am inclined to believe warm neutral is the most extreme case, and I definitely still think we will go neutral, only for the ASO timeframe to feature cooling of the Pacific again. So in other words, a double dip toward cool neutral or weak La Nina is what I am willing to bet


Edit: Now if this year's sst anomalies in the EPAC are below average but not quite as profound as 2020, that may increase the chances of an El Nino occurring in 2022 or 2023 I would think. However, that would be a discussion for later this year and early next year.

[Kingarabian]

Warm water at depth has expanded in areal extent and magnitude in the wpac (fairly typical la nina response) Need to watch for a downwelling wave and whether or not 850 u-wind anomalies are favorable for its propagation. A 2006-esque scenario is still very much in the cards

https://i.imgur.com/H9DBEsA.png

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

https://i.imgur.com/2hL10T8.png

I could be wrong and I hope I am, but I simply cannot see a "2006-eque" scenario unfolding since historically speaking, I simply cannot find any example of any recorded time when a moderately strong La Nina took place, only for the subsequent year to feature an El Nino. I am inclined to believe warm neutral is the most extreme case, and I definitely still think we will go neutral, only for the ASO timeframe to feature cooling of the Pacific again. So in other words, a double dip toward cool neutral or weak La Nina is what I am willing to bet


Edit: Now if this year's sst anomalies in the EPAC are below average but not quite as profound as 2020, that may increase the chances of an El Nino occurring in 2022 or 2023 I would think. However, that would be a discussion for later this year and early next year.

Yeah that's the best bet. It's just really really hard to get a warm-ENSO event right after a healthy moderate La Nina.

Only theoretical way to get a warm-neutral ENSO/El Nino by JAS, is if there is a substantial WWB near the dateline within the next 60 days. For the past week, the 90 day CFS 850mb wind forecast (which is extremely in-consistent to say the least) has been showing this (substantial WWB) occurring during the first week of April. We can't trust models past a couple of days, so it's impossible to put stock into something 30-60 days out. Just have to wait and see.

[weeniepatrol]

I could be wrong and I hope I am, but I simply cannot see a "2006-eque" scenario unfolding since historically speaking, I simply cannot find any example of any recorded time when a moderately strong La Nina took place, only for the subsequent year to feature an El Nino. I am inclined to believe warm neutral is the most extreme case, and I definitely still think we will go neutral, only for the ASO timeframe to feature cooling of the Pacific again. So in other words, a double dip toward cool neutral or weak La Nina is what I am willing to bet


Edit: Now if this year's sst anomalies in the EPAC are below average but not quite as profound as 2020, that may increase the chances of an El Nino occurring in 2022 or 2023 I would think. However, that would be a discussion for later this year and early next year.

yeah, i still believe cool neutral/weak nina is likeliest. But it's only early March and things can change

[Category5Kaiju]

There also seems to be this widespread sentiment that El Ninos automatically mean good news for the Atlantic; this is a dangerous attitude to have. If 1969 (Camille), 1979 (David and Frederick), 1992 (Andrew), 2002 (Lili and Isidore), 2004 (Charley, Frances, Ivan, and Jeanne), 2015 (Joaquin), 2018 (Florence and Michael), and 2019 (Dorian), all years that occurred near or during an El Nino episode, served as any indication, it is that even during El Nino years, the Atlantic can very well churn up one or more devastating and powerful hurricanes. If 2021 or (more likely) 2022 or 2023 features a developing El Nino, Atlantic residents should still not become complacent. Who knows if that one struggling tropical wave manages to be "lucky," encounter a region of very favorable conditions, and become a powerful hurricane? Sure El Nino years tend to not feature as many or severe storms as neutral or La Nina years, but the fact that El Nino years STILL have the potential to allow for AT LEAST ONE devastating Atlantic storm (it only takes one?) is all that needs to be said.

[cycloneye]

Niño 3.4 warms up to -0.7C after last weeks -1.2C reading.

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