ENSO Updates (2007 thru 2023)

[Kingarabian]

I guess it depends on the Kelvin wave... if it breaks up or not.

[cycloneye]

The April update by ECMWF is out and shows a big spread of the members as time goes by.What does that mean is the question. El Nino or not?

[NDG]

Wow, that's one heck of a spread in its long range.

[hurricanetrack]

Wow. ECMWF maybe showing that it does not know what will happen with ENSO this year. Very interesting indeed and thanks for posting Luis.

[Kingarabian]

SOI is still falling however.

[wxman57]

I see a definite trend toward a stronger El Nino in the April update. Less members are indicating neutral conditions now.

[hurricanetrack]

The latest from CPC/IRI shows that neutral conditions still hang on by a slim margin come A/S/O. However, if you look at J/A/S, neutral conditions are favored fairly significantly compared to El Nino. So we'll see. The one great thing about this- we will know FOR SURE by the time we get to August which model was right!

http://iri.columbia.edu/climate/ENSO/cu ... igure1.gif

[hurricanetrack]

And this is directly from the April 5th update from CPC/IRI:

"A majority of models predict ENSO-neutral conditions for March-May 2012, continuing through the Northern Hemisphere summer 2012 (Fig. 7). Based on the continued weakening of the negative SST anomalies during March 2012, and on the historical tendency for La Niña to dissipate during the Northern Hemisphere spring, we continue to expect La Niña to dissipate during April 2012. ENSO-neutral conditions are then expected to persist through the summer. Thereafter, there is considerable uncertainty in the forecast, which slightly favors ENSO-neutral or developing El Niño conditions over a return to La Niña conditions during the remainder of 2012 (see: CPC/IRI consensus forecast)."

[cycloneye]

Climate Prediction Center 4/16/12 Update

This week's update has Nino 3.4 at -0.3C and that is the same as last week's update. Is important to point out that Nino 1-2 has continued to warm and now is up to +1.9C

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

[Ntxw]

I see a definite trend toward a stronger El Nino in the April update. Less members are indicating neutral conditions now.

I noticed that too. Though there is a spread, the spread has trended up and consensus still warm-neutral to El Nino. Not a genius guess by any means but I think we can officially line out any possibilities of a third Nina

Also the MJO is working it's way through the western hemisphere and may return there once again. The eastern regions will show most of the warming rest of this month imo to reflect this as evident with the latest enso update.

[Kingarabian]

Flirting with -8. I believe when it starts to fall below -8, the chances for an El-Nino to come soon are high.

[joshb19882004]

soi has hit -8.0 http://www.bom.gov.au/climate/enso/monitoring/soi30.png

[cycloneye]

soi has hit -8.0 http://www.bom.gov.au/climate/enso/monitoring/soi30.png

However,it should stop the drop and go up again as the dailys are now positive.

http://www.longpaddock.qld.gov.au/seaso ... soivalues/

[cycloneye]

Mid April update of ENSO Models

If you look at the lines,only a handfull of them cross into the Moderate El Nino threshold of +1.0C. The majority of them are in the Warm Neutral/Weak El Nino area when the peak of the North Atlantic Hurricane season in ASO.





http://portal.iri.columbia.edu/portal/s ... 2&userID=2

Expected Conditions

What is the outlook for the ENSO status going forward? The official diagnosis and outlook was issued earlier this month in the NOAA/Climate Prediction Center ENSO Diagnostic Discussion, produced jointly by CPC and IRI. It stated that La Niña conditions were still in force at that time. Now, in the middle of April, a new set of model ENSO predictions is available as shown in the IRI/CPC ENSO prediction plume, discussed below. The current east-central tropical Pacific SSTs are still below average, but only very slightly, and are no longer at the -0.45 threshold required to be indicative of La Niña. Subsurface temperatures across the equatorial Pacific not only weakened to near-average during March, but now in April feature more of a heat surplus than a deficit in the upper part of the ocean from the date line eastward to 100W. The thermocline depth along the equator is now above average in the western and central tropical Pacific as well as the far eastern portion, with only weakly shallower than average depth from about 100W to 150W. Acknowledgement of the dissipation of the weak La Niña condition that existed at the beginning of April is expected in the official consensus ENSO forecast and discussion to come in early May, as the warming that has occurred in the last two weeks is not anticipated to be a short-term fluctuation that will return to La Niña levels later in April or May.

As of mid-April, most of the dynamical and statistical models predict ENSO-neutral conditions for the Apr-Jun season, while only one or two continue to show a weak La Niña condition. All models then indicate warming from their starting anomaly values. For the Apr-Jun season, 8% of the models indicate La Niña conditions, while 92% indicate neutral conditions. Jumping forward to Jul-Sep, 62% indicate neutral conditions and 38% predict El Niño conditions. At lead times of 3 or more months into the future, statistical and dynamical models that incorporate information about the ocean's observed subsurface thermal structure generally exhibit higher predictive skill than those that do not. For the Jul-Sep season, among models that do use subsurface temperature information, 55% predict ENSO-neutral SSTs, and 45% predict El Niño conditions. (Note 1). Caution is advised in interpreting the distribution of model predictions as the actual probabilities. At longer leads, the skill of the models degrades, and skill uncertainty must be convolved with the uncertainties from initial conditions and differing model physics, leading to more climatological probabilities in the long-lead ENSO Outlook than might be suggested by the suite of models. Furthermore, the expected skill of one model versus another has not been established using uniform validation procedures, which may cause a difference in the true probability distribution from that taken verbatim from the raw model predictions.


An alternative way to assess the probabilities of the three possible ENSO conditions is more quantitatively precise and less vulnerable to sampling errors than the categorical tallying method used above. This alternative method uses the mean of the predictions of all models on the plume, equally weighted, and constructs a standard error function centered on that mean. The standard error is Gaussian in shape, and has its width determined by an estimate of overall expected model skill for the season of the year and the lead time. Higher skill results in a relatively narrower error distribution, while low skill results in an error distribution with width approaching that of the historical observed distribution. This method shows probabilities for La Niña at 10% for Apr-Jun, decreasing to single digit probabilities between 5% and 10% through the remainder of 2012. Model probabilities for ENSO-neutral conditions are 88% for Apr-Jun, settling to near 50% from Jul-Sep onward. Probabilities for El Niño are near 1% for Apr-Jun, 20% for May-Jul, 35% for Jun-Aug, and 44% for Jul-Sep, remaining approximately in the 42-46% range for most of the remainder of 2012. A plot of the probabilities generated from this most recent IRI/CPC ENSO prediction plume using the multi-model mean and the Gaussian standard error method summarizes the model consensus out to about 10 months into the future. The same cautions mentioned above for the distributional count of model predictions apply to this Gaussian standard error method of inferring probabilities, due to differing model biases and skills. In particular, this approach considers only the mean of the predictions, and not the total range across the models, nor the ensemble range within individual models.


The probabilities derived from the more than 25 models on the IRI/CPC plume describe, on average, dissipation of the La Niña around initialization time (early April). This dissipation is confirmed by recent data showing the Nino3.4 index at negative levels weaker than the -0.45 C threshold for La Niña. Currently, for the middle and second half of the year, while neutral ENSO appears most likely, development of El Niño also has a reasonable chance. (but still falling short of 50%) Redevelopment of La Niña appears very unlikely, according to the models, despite that a few models indicate cool-neutral conditions through the calendar year. Factors such as known specific model biases and recent changes that the models may have missed will be taken into account in the next official outlook, which includes some human judgement in combination with the model guidance, generated by CPC and IRI, to be issued early in May.

[NDG]

So in another words, neutral conditions still have a higher chance of remaining through the hurricane season than El Nino conditions.

[cycloneye]

The 30 day SOI index has gone up again in the past couple of days after it plundged bigtime for the last 5 weeks. In one day,it went from -8.0 to -7.0. The daily SOI has gone up first and that is why the 30 day index follows.

http://www.longpaddock.qld.gov.au/seaso ... soivalues/

[cycloneye]

Here is the April update of EUROSIP or ECMWF ensembles that most of the experts follow. It shows Moderate El Nino during August,September and October,but with a little more spread at long range on this April update than in the March one. IMO.if El Nino comes,it would be a weak one,but is only my thinking.

March Update:



April Update:

[NDG]

Just a reminder of how erroneous even the Eurosip was last year past its 3 month forecast from April.
Good bet that 3 months from now ENSO will be warm-neutral to weak El Nino, but to bet that we will have a moderate El Nino like its ensembles mean show by the heart of the hurricane season would be a bad bet, IMO.

[Ntxw]

^ Actually that wasn't a bad forecast for such a long way out last year. It did rise to cool/neutral and fell back to La Nina by fall. You can see the consensus, not perfect but not terrible by any means given a small margin of error which grows as you go longer.

Regarding the SOI and it's fluctuations, this is why longer range SOI (30+ days) is more important. It's risen since the MJO has moved to the other side (from the Pacific). Should return by end of this month (and again mid May) if model trends are correct. Several more opportunities for the SOI to once again tank before the onslaught of hurricane season, we sha'll see!

[cycloneye]

Climate Prediction Center 4/23/12 Update

There was a slight cooling at Nino 3.4 as in this update is down to -0.4C less warm than the -0.3C that was in last week's update. Also,the other areas in the Pacific cooled down,even the Nino 1+2 area close to SouthAmerica,where is went down from +1.9C on last week's update to +1.5C on this update.

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