E.N.S.O. Discussion

[Don]

3 hours ago, SqueakheartLW said:

Now if this isn't good news for coldies then what will it take for the pieces to fall right for once.

A cooling in region 1+2, plus still too many later (blue) ensembles going into super territory.  However, a defo shift in the right direction!

Edited August 27, 2023 by Don

[Addicks Fan 1981]

Niño 1 & 2 3.1

Niño 3        2.2

Niño 3.4     1.5

Niño 4         1.1

Edited August 28, 2023 by Addicks Fan 1981

[Cheshire Freeze]

Remember, I punted on a strong moderate or weakly strong Modoki a couple of months ago

[Addicks Fan 1981]

Looks that's exactly where its heading @CreweCold .   

[summer blizzard]

Would have to disagree with this, at least outside the dying embers early next year.

A proper modiki Nino is modiki at peak and we like that because at peak it's forcing the strong convection to be at its highest amplitude over or west of the dateline allowing for poleward heat transport in the right place. By the time 2009 peaked in December, it had 3.4 at +1.7 but 1.2 had already fallen to +0.6. That's a heavy gradient. Or Jan 92 which peaked at +1.7 in 3.4 with 1.2 at 0.1. 

What models currently show is a cooler version of 2015 which peaked in Nov at +2.8 with 1.2 at 2.0. You have a decent gradient but the sheer warmth still available will not make it a Modiki. 

Currently, i think it's reasonable to believe this will end up warmer in the west as Nino 1.2 cools but a Modiki, i don't see that being credible anywhere near peak. Thus, basin wide continues to be my favoured bet (not that this is always bad, 92 was modiki and the winter was pretty average while 87 was basin wide and the winter produced).

 

Edited August 28, 2023 by summer blizzard

[Addicks Fan 1981]

22 minutes ago, summer blizzard said:

Would have to disagree with this, at least outside the dying embers early next year.

A proper modiki Nino is modiki at peak and we like that because at peak it's forcing the strong convection to be at its highest amplitude over or west of the dateline allowing for poleward heat transport in the right place. By the time 2009 peaked in December, it had 3.4 at +1.7 but 1.2 had already fallen to +0.6. That's a heavy gradient. Or Jan 92 which peaked at +1.7 in 3.4 with 1.2 at 0.1. 

What models currently show is a cooler version of 2015 which peaked in Nov at +2.8 with 1.2 at 2.0. You have a decent gradient but the sheer warmth still available will not make it a Modiki. 

Currently, i think it's reasonable to believe this will end up warmer in the west as Nino 1.2 cools but a Modiki, i don't see that being credible anywhere near peak. Thus, basin wide continues to be my favoured bet (not that this is always bad, 92 was modiki and the winter was pretty average while 87 was basin wide and the winter produced).

 

Do you think the models are overdoing the IOD predictions @summer blizzard?

[Metwatch]

The Australian Bureau of meteorology have declared an El Niño and a positive Indian Ocean Dipole (IOD) are now taking place.

 

Edited September 19, 2023 by Metwatch

[summer blizzard]

30AUG2023: Nino3: 2.3 , Nino3.4: 1.6 , Nino4: 1.1

06SEP2023: Nino3: 2.2 , Nino3.4: 1.6 , Nino4: 1.1

13SEP2023: Nino3: 2.2 , Nino3.4: 1.6 , Nino4: 1.1

 

August ONI was +1.3.

JJA ONI was +1.1.

 

[summer blizzard]

JJA ONI came in at +1.1. 

To update our list and ranking. 

Our updated list for AMJ.

1957: +1.3

1972: +1.1

1976: +0.2

1986: +0.2

2002: +0.8

2009: +0.5

2014: 0.0

2018: 0.1

2023: +1.1

We've moved to joint second (this is where 2014 went off the boil for a bit as well).

 

To update on our ENSO trades index, August finally coupled and came in at -0.6 (though September looks like it might struggle to maintain this)..

https://www.cpc.ncep.noaa.gov/data/indices/cpac850

To compare to our primary analogue list since 1979 (standardised):

1986: -0.8

2002: -0.2

2009: -0.5

2014: -0.8

2018: -0.6

2023: -0.6

 

Remember that our analysis last month showed a corellation between how early the event coupled and eventual strength so this may be another sign that the models are OTT (i still lean in the +1.3 to +1.7 range). 

[summer blizzard]

Still quite a split between dynamic and statistical models. 

Since the forecast is for a peak in NDJ most likely it's worth saying that we probably only have 2 or 3 waves to cross the Pacific at whatever strength they can get. So far the big ones were in March, May and August.

Cold pool is present though not especially strong with a somewhat more traditional colder west-warmer east split for a Nino. 

No significant convection around currently though in the forecast, hence the somewhat stall in ENSO development. 

 

[sebastiaan1973]

https://www.youtube.com/watch?v=mggRl80WzbE&ab_channel=Astrum

[summer blizzard]

20SEP2023: Nino3: 2.1 , Nino3.4: 1.7 , Nino4: 1.2

Edited September 27, 2023 by summer blizzard

[summer blizzard]

27SEP2023: Nino3: 2.0 , Nino3.4: 1.5 , Nino4: 1.1

ONI for September increased to +1.6. 

JAS should come in around +1.3.

[sebastiaan1973]

An intresting read

https://journals.ametsoc.org/view/journals/clim/28/3/jcli-d-14-00398.1.xml

Empirical orthogonal function (EOF) analysis is frequently applied to derive patterns and indexes used to identify and track weather and climate modes as expressed in state variables or proxies of convection. Individual EOFs or pairs of EOFs are often taken to be a complete description of the phenomenon they are intended to index. At the same time, in the absence of projection of the phenomenon onto multiple EOFs yielding multiple similar eigenvalues, each EOF is often assumed to represent a physically independent phenomenon. This project analyzed the leading EOFs of the earth’s skin temperature on the equator and outgoing longwave radiation (OLR) anomalies filtered for atmospheric equatorial Kelvin waves. Results show that the leading two EOFs of the skin temperature data—including east Pacific El Niño and El Niño Modoki—frequently evolve as a quadrature pair during El Niño events, even though the first EOF explains roughly 6 times as much variance as the second. They together diagnose the longitude of the SST anomaly maximum, and their linear combination frequently shows eastward or westward propagation. Analysis of the filtered OLR anomalies shows that the first six EOFs each represent Kelvin wave signals, with the first, second, and third pairs representing Kelvin waves characterized by zonal wavenumbers 2, 3, and 4, respectively. This result demonstrates that if a phenomenon occurs across a range of spatial scales, it is described by multiple EOFs at different scales. A similar analysis demonstrates that the Madden–Julian oscillation probably exhibits spread across a range of spatial scales that would also require multiple EOFs for full characterization.

[summer blizzard]

04OCT2023: Nino3: 1.9 , Nino3.4: 1.5 , Nino4: 1.2

[summer blizzard]

JAS ONI came in at +1.3. 

To update our list and ranking. 

Our updated list for AMJ.

1957: +1.3

1972: +1.4

1976: +0.4

1986: +0.4

2002: +0.9

2009: +0.6

2014: 0.1

2018: 0.2

2023: +1.3

We remain joint second.

 

To update on our ENSO trades index, September weakened a little to -0.3 but remained net westerly. 

https://www.cpc.ncep.noaa.gov/data/indices/cpac850

To compare to our primary analogue list since 1979 (standardised):

1986: -0.4

2002: -1.0

2009: +0.4

2014: -0.1

2018: -0.7

2023: -0.3

 

Remember that our analysis last month showed a corellation between how early the event coupled and eventual strength so this may be another sign that the models are OTT (i still lean in the +1.3 to +1.7 range). 

[summer blizzard]

11OCT2023: Nino3: 2.1 , Nino3.4: 1.5 , Nino4: 1.3

[sebastiaan1973]

Tweet by Ben Noll.

[summer blizzard]

18OCT2023: Nino3: 2.1 , Nino3.4: 1.6 , Nino4: 1.3

[summer blizzard]

25OCT2023: Nino3: 2.0 , Nino3.4: 1.6 , Nino4: 1.3

October ONI should come in at +1.6. 

ASO ONI likely to come in around +1.5.

[summer blizzard]

01NOV2023: Nino3: 2.1 , Nino3.4: 1.8 , Nino4: 1.4 

New peak in 3.4 and 4. 

ONI for ASO was confirmed as +1.5, the first five months are the warmest since 1997 (also beaten by 1975 and 1962). At 5 tri-monthlies, this is now official.  

[summer blizzard]

ASO ONI came in at +1.5. 

To update our list and ranking. 

Our updated list for ASO.

1957: +1.3

1972: +1.6

1976: +0.6

1986: +0.7

2002: +1.0

2009: +0.7

2014: +0.2

2018: +0.5

2023: +1.5

We remain second.

 

To update on our ENSO trades index, October strengthend to -0.8 as we finally saw the Indian Ocean shutdown with the end of the Monsoon. 

https://www.cpc.ncep.noaa.gov/data/indices/cpac850

To compare to our primary analogue list since 1979 (standardised):

1986: -0.4

2002: -0.6

2009: -1.1

2014: -0.3

2018: -0.8

2023: -0.8

 

MEI did fall back but this was likely due to the weaker westerlies in September so the next update should bounce back. 

 

Atmosphere continues to favour strongest forcing west of the dateline. 

 

Sub-Surface as you would expect. 

 

[summer blizzard]

08NOV2023: Nino3: 2.0 , Nino3.4: 1.8 , Nino4: 1.3

Outlook is for another nudge up over the next week or two before stable or cooling. 

http://www.atmos.albany.edu/student/ventrice/real_time/timeLon/u.anom.30.5S-5N.gif

Edited November 16, 2023 by summer blizzard

[summer blizzard]

Nino is now very close to peak. 

Basically, that blob of 30C SST has been proceeding east (and weakening) as the west Pacific has cooled faster than the ENSO zones being sustained from the east. As it is clearing the main Nino zones over the next month or so, GFS is suggesting that the weak standing wave observed over the west pacific since the end of the moonsoon will shift east towards the dateline (and in turn, Nino 3) however the enhanced easterlies behind it will likely cool Nino 4 (then 3) as this happens like we see in the West Pacific. 

Above is the pattern since the monsoon ended and ENSO/IOD had a greater impact on the pattern. 

Above here though is the GFS forecast showing a shift east (also indicated on a Euro forecast plot posted by Matt Hugo in another thread). 

..

As allided to above, persistent convection in this region could see December (and possibly January) peak warmer than they are now however as Nino 4 drops, we will start to see the warming in Nino 3 cancelled out, especially as the wave should progressively weaken as it moves. As such this sugests that we are quite close to peak now in Nino 4 and somewhere close in Nino 3 (the 90 day chart suggests a month or so before the pattern shifts east on its journey). 

For winter purposes it's a mixed bag. If forcing nudges east with it then it favours MJO 6-7-8-1 which are good (at least compared to phases 4-5) however relaxed trades in the Indian Ocean can also encourage phases 2-3 which are not always great (wrong place to support -AO normally). The Aleutian Low is also normally in the mean close to directly north of the primary forcing and generally the further west the better. 

[Redbull165]

And its happening. For the first time this year when El nino developed, we are seeing Enso area 3.4 warmer with anomalies than 1+2. Modoki El nino slowly taking its place.

Difference in last 7 days. The western part over the Pacific is seeing a lot of warming last few days, the eastern part quite the opposite around the coast of Ecuador.

 

Edited November 18, 2023 by Redbull165