ENSO Updates (2007 thru 2023)

[Category5Kaiju]

Just out of curiosity, but is there a reason why it seems like La Ninas are "easier" to get and last multiple years while El Ninos typically occur for one year and then disappear the next, only to be replaced by a La Nina?

[AlphaToOmega]

Just out of curiosity, but is there a reason why it seems like La Ninas are "easier" to get and last multiple years while El Ninos typically occur for one year and then disappear the next, only to be replaced by a La Nina?

ENSO neutral and La Nina are basically the same pattern; the difference is that La Ninas have stronger easterly winds than ENSO neutral. El Ninos, on the other hand, have westerly winds.

[Kingarabian]

Just out of curiosity, but is there a reason why it seems like La Ninas are "easier" to get and last multiple years while El Ninos typically occur for one year and then disappear the next, only to be replaced by a La Nina?

To simplify it, the winds across the equatorial pacific are naturally east to west. So it's a lot harder to get those trade winds to significantly slow down and allow water to build up in the WPAC and move to the CPAC/EPAC.

[Yellow Evan]

Climo is winning here and we'll likely see a return to La Nina. After a double dip La Nina, climo favors +ENSO of some sort. Though they can fail(see 2012).

What? Maybe a triple dip La Niña?

Historically that isn't too unprecedented. 1998-2001 was more or less a quadruple dip and 1973-75 was a triple dip and for now at least PDO/PMM aren't positive (though this could definitely change), which that combined with the wet Sahel rainfall pattern, would make El Nino events less frequent/intense.

[Category5Kaiju]

Climo is winning here and we'll likely see a return to La Nina. After a double dip La Nina, climo favors +ENSO of some sort. Though they can fail(see 2012).

What? Maybe a triple dip La Niña?

Historically that isn't too unprecedented. 1998-2001 was more or less a quadruple dip and 1973-75 was a triple dip and for now at least PDO/PMM aren't positive (though this could definitely change), which that combined with the wet Sahel rainfall pattern, would make El Nino events less frequent/intense.

It's really hard to believe that we have not had a "true" El Nino that suppressed Atlantic activity since 2015. Also thanks Kingarabian and AlphatoOmega, those explanations really helped!

[Kingarabian]

What? Maybe a triple dip La Niña?

Historically that isn't too unprecedented. 1998-2001 was more or less a quadruple dip and 1973-75 was a triple dip and for now at least PDO/PMM aren't positive (though this could definitely change), which that combined with the wet Sahel rainfall pattern, would make El Nino events less frequent/intense.

It's really hard to believe that we have not had a "true" El Nino that suppressed Atlantic activity since 2015. Also thanks Kingarabian and AlphatoOmega, those explanations really helped!

Well the 2015 El Nino was a super El Nino. Those are very rare. We just had a double dip El Nino in 2018/2019 IMO although the CPC disagrees.

[Category5Kaiju]

Historically that isn't too unprecedented. 1998-2001 was more or less a quadruple dip and 1973-75 was a triple dip and for now at least PDO/PMM aren't positive (though this could definitely change), which that combined with the wet Sahel rainfall pattern, would make El Nino events less frequent/intense.

It's really hard to believe that we have not had a "true" El Nino that suppressed Atlantic activity since 2015. Also thanks Kingarabian and AlphatoOmega, those explanations really helped!

Well the 2015 El Nino was a super El Nino. Those are very rare. We just had a double dip El Nino in 2018/2019 IMO although the CPC disagrees.

Oh yeah I thought the 2019-2020 +ENSO was initially classified as an extremely short-lived El Nino, but it fell short of one 3 month period at or above 0.5 C (had SON or FMA met that, then it would have been classified as an El Nino).

[Yellow Evan]

What? Maybe a triple dip La Niña?

Historically that isn't too unprecedented. 1998-2001 was more or less a quadruple dip and 1973-75 was a triple dip and for now at least PDO/PMM aren't positive (though this could definitely change), which that combined with the wet Sahel rainfall pattern, would make El Nino events less frequent/intense.

It's really hard to believe that we have not had a "true" El Nino that suppressed Atlantic activity since 2015. Also thanks Kingarabian and AlphatoOmega, those explanations really helped!

African standing wave pattern likely is preventing that by basically guaranteeing -VP over Africa, hence the relative activity of 2018 and 2019.

[Kingarabian]

It's really hard to believe that we have not had a "true" El Nino that suppressed Atlantic activity since 2015. Also thanks Kingarabian and AlphatoOmega, those explanations really helped!

Well the 2015 El Nino was a super El Nino. Those are very rare. We just had a double dip El Nino in 2018/2019 IMO although the CPC disagrees.

Oh yeah I thought the 2019-2020 +ENSO was initially classified as an extremely short-lived El Nino, but it fell short of one 3 month period at or above 0.5 C (had SON or FMA met that, then it would have been classified as an El Nino).

Yeah 2018 was a legit El Nino event but 2019 fell just short of the CPC requirement.

[cycloneye]

Neutral thru August and from September thru the next few months La Niña.

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).

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

[cycloneye]

More in depth details of the July update in the ENSO Blog.

Where’s the beef?
Is it all that unusual to have two La Niña winters back-to-back? Nope! In fact, of the twelve first-year La Niña events, eight (!) were followed by La Niña the next winter, two by neutral, and two by El Niño. Honestly, with those numbers, it would have been more surprising if we thought neutral conditions would continue all year.

Putting all of those 12 first-year La Niñas together with 2020-2021, it’s evident how much this last year doesn’t stand out. Though, twelve past cases are not a ton to rely on by itself. This La Niña Watch is buoyed by much more than that.

One specific reason why and when any change to ENSO is important is the potential influence on the Atlantic and eastern Pacific hurricane season. As noted on the ENSO Blog in the past, La Niña can help make atmospheric conditions more conducive for tropical cyclones to form the Atlantic, and less conducive in the Eastern Pacific. If 2021 so far is any indicator, it could be an active year:

https://www.climate.gov/news-features/b ... %B1a-watch

[cycloneye]

El Niño is way down in the percents between 3% and 4% thru the first months of 2022 thru April.



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

[cycloneye]

The Aussies updated their forecast going to La Niña by the fall.



http://www.bom.gov.au/climate/model-sum ... ific-Ocean

[kevin]

The Aussies updated their forecast going to La Niña by the fall.

https://i.imgur.com/tKHo39r.png

http://www.bom.gov.au/climate/model-sum ... ific-Ocean

So it looks like we'll be in cool-neutral or La Nina during peak season .

[Stormybajan]

The Aussies updated their forecast going to La Niña by the fall.

https://i.imgur.com/tKHo39r.png

http://www.bom.gov.au/climate/model-sum ... ific-Ocean

So it looks like we'll be in cool-neutral or La Nina during peak season .

Even though some are skeptical about having an above average season with the cool MDR SSTS (which imo are most likely EXACTLY average not below or above). With the emergence of cool-neutral ENSO I dont see why we wont have our 6th above average season in a row . Even with the average MDR SSTs right now I am pretty confident in saying by August 15th they will be warm enough to sustain Major Hurricane development by the time we get there...

[cycloneye]

 https://twitter.com/AndyHazelton/status/1414623866819858433

[Kingarabian]

Yup. #climoGang

[Category5Kaiju]

The Aussies updated their forecast going to La Niña by the fall.

https://i.imgur.com/tKHo39r.png

http://www.bom.gov.au/climate/model-sum ... ific-Ocean

So it looks like we'll be in cool-neutral or La Nina during peak season .

Even though some are skeptical about having an above average season with the cool MDR SSTS (which imo are most likely EXACTLY average not below or above). With the emergence of cool-neutral ENSO I dont see why we wont have our 6th above average season in a row . Even with the average MDR SSTs right now I am pretty confident in saying by August 15th they will be warm enough to sustain Major Hurricane development by the time we get there...

I guarantee you that things will warm up by then; in fact, I would be surprised if by peak season BOTH the EPAC and Atlantic are both experiencing near or cooler than average sst anomalies. Can't remember the last time something like this happened.

[toad strangler]

Great tweet for the ENSO challenged like me lol

 http://twitter.com/jnmet/status/1416040261680082950

[abajan]

Disco on ENSO is at 5:42 into Mark Sudduth's video published a few hours ago:



Link: https://youtu.be/V_YLCbcrXqM