ENSO Updates (2007 thru 2023)

[cycloneye]

This week's update for 3.4 is -0.3C

Thank you for posting the info as I was without power for almost 12 hours yesterday. And the up and downs continue.

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

[cycloneye]

The 30 day SOI index has turned positive.

[Ntxw]

The 30 day SOI index has turned positive.

It's interesting because we've strung together a couple of 20+ values. It's going to rise some more then probably crash again. GWO+ is back in phase 5 and the MJO is in the Pacific. We'll likely see another crazy dive of it again here in a couple weeks as the latest mountain torque event pushes the MJO east, let the wild up and downs continue.

[cycloneye]

Climate Prediction Center March update

They expanded the Neutral conditions to include the Summer but they caution about the Spring barrier of the models.

http://www.cpc.ncep.noaa.gov/products/a ... odisc.html

Synopsis: ENSO-neutral is favored into the Northern Hemisphere summer 2013.

During February 2013, ENSO-neutral continued although SSTs remained below average across the eastern half of the equatorial Pacific Ocean (Fig. 1). The Niño 3.4 index remained near -0.5oC, while the Niño 3 index became less negative as the month progressed (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) similarly increased during the month (Fig. 3), largely due to the eastward push of above-average temperatures at depth (Fig. 4). The Madden-Julian Oscillation (MJO) again contributed to increased atmospheric variability over the tropical Pacific during February. Anomalous low-level winds were primarily easterly over the west-central equatorial Pacific, while upper-level winds remained near average, but with some intra-monthly variability. Over Indonesia, anomalous convection remained enhanced north of the equator and suppressed south of the equator (Fig. 5). Due to the lack of persistent atmosphere-ocean coupling, the tropical Pacific continues to reflect ENSO-neutral.

Most models forecast Niño-3.4 SSTs to remain between 0oC and -0.5oC through Northern Hemisphere spring and to remain ENSO-neutral (between -0.5oC and +0.5oC) into the fall (Fig. 6). However, there is increasing model spread and overall less confidence in the forecast during the last half of the year, partly because of the so-called “spring barrier,” which historically leads to lower model skill beginning in late spring. Thus, ENSO-neutral is favored into the Northern Hemisphere summer 2013 (see CPC/IRI consensus forecast).

[cycloneye]

The early March update of the models show a Neutral domination for the forecast period but El Nino creep upwards.

[cycloneye]

Climate Prediction Center 3/11/13 weekly update

A warming trend has been occuring in the past two weeks as Nino 3.4 has been up from -0.5C two weeks ago to now -0.1C. Two questions come to mind about this warming trend. Will this warming trend is the start of the resurgence of El Nino? Or this is only a brief warming spell?

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

[cycloneye]

The MJO is in the West Pacific and that is the cause of the present warming trend. The question is if the warming will continue or cooling begins to dominate soon.

[Ntxw]

The MJO is in the West Pacific and that is the cause of the present warming trend. The question is if the warming will continue or cooling begins to dominate soon.

Most recent mountain torque event from Asia will allow the MJO to progress into the western Hemisphere (GWO+). This should last until about the end of March. Subtle warming will probably happen on and off. Once the wave returns to the Indian Ocean beginning April we start the process again. If it stalls in Indonesia runaway cooling, if not then we get more warming likely above 0c.

[cycloneye]

The 30 day SOI is still rising.

[TropicalAnalystwx13]

The GWO (corrected) has been--and is--in its high AAM phase lately. It makes sense to see a little warming.

We should see cooling come back during early April as we enter the low AAM phase. A rising SOI supports this.

[cycloneye]

Climate Predicton Center 3/18/13 weekly update

Some cooling occured in the past few days and the data reflects it as it went down from -0.1C to this week's -0.3C

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

[Hurricane Andrew]

Alright, this is driving me bananas. Does a positive SOI spike warm or cool temps in the NINO regions?

[TropicalAnalystwx13]

Alright, this is driving me bananas. Does a positive SOI spike warm or cool temps in the NINO regions?

The Southern Oscillation Index (SOI) is a measure of the pressure difference between Tahiti and Darwin. A higher pressure difference between these two locations typically promotes stronger-than-average trade winds, and thus evaporational cooling, which eventually may lead to a La Niña. The opposite is the case for a lower pressure difference.

So, the higher the SOI value, the more likely you are to find cool ocean temperatures along the equator.

[Ntxw]

Basically what TropicalAnalystwx13 said. I would like to add a few things to it. When using SOI it is best to look at 90 day if you are thinking long term for ENSO as Ninos/Ninas are longer based forecasting. It is much more stable and reflects the ENSO state as well as where it may head the next month or few. 30 day SOI is good to use weekly of cooling or warming. Daily SOI is highly variable and sometimes are skewed by local weather patterns and the MJO. When the daily shoots way up or down, then it's worth noting.

For the past 6+ months daily SOI and 30 day has crashed down and rocketed up like crazy but the 90 day has remained stable around neutral values, which is what ENSO did.

[cycloneye]

Mid-March update of ENSO models

Almost all are in Neutral thru the peak of the season in ASO. Some are in warm Neutral and others are in cold Neutral. I included the text of the update below the graphics as the last paragraph is important and I highlighted in red.





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

Technical ENSO Update
21 March 2013
Recent and Current Conditions
After a brief period of borderline El Niño SST conditions between July and September 2012, the SST anomaly in the Nino3.4 region returned to neutral levels during October and has remained neutral through mid-March 2013. For February 2013 the Nino3.4 SST anomaly was -0.40 C, indicative of cool-neutral ENSO conditions, and for December-February the anomaly was -0.31 C. Since late 2011, the IRI's definition of El Niño conditions has become the same as that of NOAA/Climate Prediction Center, in which the SST anomaly in the NINO3.4 region (5S-5N; 170W-120W) exceeds 0.5 C. Similarly, for La Niña, the anomaly must be -0.5 C or less. The climatological probabilities for La Niña, neutral, and El Niño conditions vary seasonally, and are shown in a table at the bottom of this page for each 3-month season. The most recent weekly SST anomaly in the NINO3.4 region was -0.3 C, indicating neutral ENSO conditions in the tropical Pacific; this is similar to the -0.40 C level observed in February.

Expected Conditions

What is the outlook for the ENSO status going forward? The most recent 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 called for a high likelihood of neutral ENSO conditions enduring through the second quarter of 2013, with probabilities of El Niño or La Niña each less than 25% through northern summer 2013. The latest set of model ENSO predictions, from mid-February, is now available in the IRI/CPC ENSO prediction plume, discussed below. Currently, SSTs are in the cool half of the ENSO-neutral range (anomaly of 0 to -0.5 C), and SST is above average in the western part of the basin. Subsurface temperatures across the equatorial Pacific average close to the climatological average, but are above average in the western half of the basin and slightly below average in the east-central tropical Pacific. In the atmosphere, the basin-wide sea level pressure pattern (e.g. the SOI), has been mainly near average but the low-level zonal winds have slightly favored enhanced trade winds. Anomalous convection (as measured by OLR) has generally been below average in the central tropical Pacific, and above average in the far western part of the basin. Together, although these last features have gradients similar to those found during weak or borderline La Niña, all of the the features collectively reflect only cool-leaning ENSO-neutral conditions.

As of mid-March, 21% of the set of dynamical and statistical models models predicts weak La Niña SST conditions for the Mar-May 2013 season, none predicts El Niño conditions, and 79% indicates neutral ENSO. 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 Jun-Aug season, among models that do use subsurface temperature information, 84% predicts ENSO-neutral SSTs, 11% predicts El Niño conditions and 5% predicts La Niña contitions. For all model types, the probability for neutral ENSO conditions is 65% or greater from Mar-May to the end of the forecast period in northern autumn 2013. (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 20% for Mar-May 2013, 27% for Apr-Jun, and also 27% for May-Jul 2013, remaining between 25% and 30% through northern autumn. Model probabilities for ENSO-neutral conditions are 80% for Mar-May 2013, 71% for Apr-Jun, and 64% for May-Jul 2013, decreasing to between 55% and 60% from Jun-Aug through autumn 2013. Probabilities for El Niño are near 0% for Mar-May 2013, 2% for Apr-Jun, rising to the 10-15% range from Jun-Aug through northern autumn. In words, the models collectively favor neutral ENSO conditions straight through to the fourth quarter of 2013; La Niña is slightly favored over El Niño during all of the period. 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 24 or more models on the IRI/CPC plume describe, on average, maintenance of neutral ENSO conditions during the coming months, continuing through into the latter half of 2013. Uncertainty increases greatly from around the Apr-Jun 2013 season onward, when the probablilities for neutral ENSO settle into the 50s and probabilities for non-neutral ENSO are approximately one-in-four for La Niña and one-in-six for El Niño. Following this latest model-based ENSO plume prediction, 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 to be generated and issued in early January by CPC and IRI, which will include some human judgement in combination with the model guidance.

[Ntxw]

Good read, looks like ENSO neutral is more or less still the favored outcome. Wolter Klaus of NOAA (Author of MEI) released the latest MEI index, which is neutral also. He also discussed in good form the historical perspective of the ENSO state we are in.


Snippet

Stay tuned for the next update by 6 April (hopefully sooner) to see where the MEI will be heading next. El Niño came and went last summer, not unlike 1953. We have just witnessed our first ENSO-neutral winter since 2003-04 (2005-06 was an ENSO-neutral winter, but much closer to La Niña, and dipped into La Niña rankings during March-April). Of the six such ENSO-neutral cases before 2012-13 shown here, two ended up as full-blown El Niño events by the end of the second year shown in this graph (1991 and 2002), while three remained more or less ENSO-neutral, and one drifted into weak La Niña territory (1967). However, during boreal spring four of these cases showed at least a brief foray into El Niño conditions, with two of them (1953 and 1981) quickly returning to ENSO-neutral later that year. The next few months could be interesting, although intrasesasonal tropical activity has weakened over the last month.

http://www.esrl.noaa.gov/psd/enso/mei/

[cycloneye]

Ntxw,do you see the PDO warming a little bit? I ask because I see the warm waters east of Japan expanding eastward.

[Ntxw]

Ntxw,do you see the PDO warming a little bit? I ask because I see the warm waters east of Japan expanding eastward.

The PDO cooled in February. Warm waters off Japan is a signal of cold PDO. Cold PDO is warm west pacific and cold east Pacific, warm PDO is the opposite.

[cycloneye]

Here is the March update of the Eurosip multi model that continue to forecast warm neutral conditions.

[Kingarabian]

What if we have back-to-back El-Nino's...