A monthly summary of the status of El Niño, La Niña, and the Southern Oscillation, or ENSO, based on the NINO3.4 index (120-170W, 5S-5N)
During October through mid-November the observed ENSO conditions remained neutral. Most of the ENSO prediction models indicate a continuation of neutral ENSO into the first quarter of 2014. During northern spring and summer a warming tendency is seen in both dynamical and statistical models.
Figures 1 and 3 (the official CPC ENSO probability forecast and the objective model-based IRI ENSO probability forecast, respectively) are often quite similar. However, occasionally they may differ noticeably. There can be several reasons for differences. One possible reason is that the human forecasters, using their experience and judgment, may disagree to some degree with the models, which may have known biases. Another reason is related to the fact that the models are not run at the same time that the forecasters make their assessment, so that the starting ENSO conditions may be slightly different between the two times. The charts on this Quick Look page are updated at two different times of the month, so that between the second and the third Thursday of the month, the official forecast (Fig. 1) has just been updated, while the model-based forecasts (Figs. 3 and 4) are still from the third Thursday of the previous month. On the other hand, from the third Thursday of the month until the second Thursday of the next month, the model-based forecasts are more recently updated, while the official forecasts remain from the second Thursday of the current month.
Click on the for more information on each figure.
El Niño/Southern Oscillation (ENSO) Diagnostic Discussion issued by the Climate Prediction Center/NCEP/NWS
During October, ENSO-neutral persisted, as reflected by near-average sea surface temperatures (SST) across much of the equatorial Pacific Ocean (Fig. 1). During the month, slightly below-average SSTs were evident in most of the Niño regions, except for Niño-4, which remained near zero (Fig. 2). However, the oceanic heat content (average temperature in the upper 300m of the ocean) rose from near average to slightly above average (Fig. 3), due to the eastward shift of a downwelling oceanic Kelvin wave, which was reflected in the above-average subsurface temperatures across the western half of the Pacific (Fig. 4). The atmospheric circulation remained largely near average during the month, with generally small departures in equatorial convection (Fig. 5) and upper and lower-level winds. Collectively, these atmospheric and oceanic conditions reflect ENSO-neutral
The majority of model forecasts indicate that ENSO-neutral (Niño-3.4 index between -0.5°C and 0.5°C) will persist into the Northern Hemisphere summer 2014 (Fig. 6). Though confidence is highest for ENSO-neutral, there are also growing probabilities for warm conditions (relative to cool conditions) toward the spring/summer 2014. The consensus forecast is for ENSO-neutral to continue through the Northern Hemisphere spring 2014 (see CPC/IRI consensus forecast).
This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC’s Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 5 December 2013. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.
| Season | La Niña | Neutral | El Niño |
|---|---|---|---|
| OND 2013 | 7% | 91% | 2% |
| NDJ 2014 | 9% | 86% | 5% |
| DJF 2014 | 9% | 82% | 9% |
| JFM 2014 | 10% | 78% | 12% |
| FMA 2014 | 10% | 74% | 16% |
| MAM 2014 | 11% | 67% | 22% |
| AMJ 2014 | 11% | 60% | 29% |
| MJJ 2014 | 12% | 55% | 33% |
| JJA 2014 | 12% | 52% | 36% |
The SST anomaly in the Nino3.4 region has been in the neutral range lately, through mid-November 2013. For October 2013 the Nino3.4 SST anomaly was -0.28 C, indicative of neutral ENSO conditions, and for August-October it was -0.23 C. The IRI’s definition of El Niño, like NOAA/Climate Prediction Center’s, requires that the SST anomaly in the NINO3.4 region (5S-5N; 170W-120W) exceed 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 0.0 C, indicating exactly average ENSO-related SST conditions in the tropical Pacific; this is slightly less cool than the -0.28 C level observed in October.
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 remainder of northern autumn into winter 2013-14, and through spring 2014, with probabilities of El Niño or La Niña each less than 30% until May-Jul 2014 when El Niño probabilities rise above that level but still less than 50%. The latest set of model ENSO predictions, from mid-September, now available in the IRI/CPC ENSO prediction plume, is discussed below. Currently, Nino3.4 SST anomalies are near the middle of the ENSO-neutral range. The SST continues to be slightly above average in the far western part of the basin, but continues to be below average in the eastern quarter of the basin, but much less strongly so than several months ago. Subsurface temperature anomalies across the central and eastern equatorial Pacific have been slightly above average since mid-May, and are now becoming somewhat more clearly/strongly positive. In the atmosphere, the basin-wide sea level pressure pattern (e.g. the SOI), and the low-level zonal winds have been approximately average across much of the basin. The upper level zonal winds are now also near-average across the tropical Pacific. Anomalous convection (as measured by OLR) has generally been negative in the west-central tropical Pacific, and positive in the far western part of the basin and Indonesia. Together, these features reflect ENSO-neutral conditions.
As of mid-November, only 8% of the set of dynamical and statistical models models predicts weak La Niña SST conditions for the Nov-Jan 2013-14 season, 4% predicts El Niño conditions, and 88% 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 Feb-Apr 2014 season, among models that do use subsurface temperature information, 76% predicts ENSO-neutral SSTs, 24% predicts El Niño conditions and none predicts La Niña conditions. For all model types, the probability for neutral ENSO conditions is near 90% from Nov-Jan 2013-14 to Jan-Mar 2014, between 74% and 83% from Feb-Apr through May-Jul 2014, and 55%-60% for Jun-Aug and Jul-Sep 2014 at the end of the forecast period.
Note – Only models that produce a new ENSO prediction every month are included in the above statement.
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 1% for Nov-Jan 2013-14, remaining at 10% or less through the end of the forecast period in northern summer 2014. Model probabilities for ENSO-neutral conditions are more than 90% from Nov-Jan 2013-14 to Jan-Mar 2014, dropping steadily during northern spring 2014, to become less than 50% from May-Jul through the end of the forecast period in Jul-Sep 2014. Probabilities for El Niño are below 10% from Nov-Jan 2013-14 to Jan-Mar 2014, thereafter steadily increasing to exceed 30% by Apr-Jun 2014 and to between 40% and 50% from May-Jul to Jul-Sep 2014 (maximizing at 48% for both Jun-Aug and Jul-Sep, the last two forecast seasons). It is clear that the models collectively favor neutral ENSO conditions into northern spring 2014; then by May-Jul El Niño probabilities become more competitive with ENSO-neutral probabilities, until they are approximately equally likely from May-Jul 2014 onward.
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 models on the IRI/CPC plume describe, on average, maintenance of neutral ENSO conditions during the coming months, continuing into northern spring 2014. The possibility of El Niño development is seen starting May-Jul 2014, and the objective model-based probabilities for that still remain just barely shy of 50% for Jun-Aug and Jul-Sep 2014. A caution regarding this latest set of model-based ENSO plume predictions, is that 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 October by CPC and IRI, which will include some human judgement in combination with the model guidance.
Using the 0.5 C thresholds, the climatological probabilities of La Nina, neutral, and El Nino conditions for each 3-month season are as follows:
| Season | La Niña | Neutral | El Niño |
|---|---|---|---|
| DJF | 37% | 28% | 35% |
| JFM | 34% | 37% | 29% |
| FMA | 30% | 48% | 22% |
| MAM | 26% | 54% | 20% |
| AMJ | 24% | 54% | 22% |
| MJJ | 25% | 51% | 24% |
| JJA | 25% | 50% | 25% |
| JAS | 27% | 46% | 27% |
| ASO | 29% | 40% | 31% |
| SON | 32% | 34% | 34% |
| OND | 34% | 31% | 35% |
| NDJ | 37% | 27% | 36% |
| Season | La Niña | Neutral | El Niño |
|---|---|---|---|
| NDJ 2014 | 1% | 99% | ~0% |
| DJF 2014 | 3% | 96% | 1% |
| JFM 2014 | 4% | 92% | 4% |
| FMA 2014 | 5% | 84% | 11% |
| MAM 2014 | 5% | 74% | 21% |
| AMJ 2014 | 7% | 59% | 34% |
| MJJ 2014 | 10% | 48% | 42% |
| JJA 2014 | 8% | 44% | 48% |
| JAS 2014 | 9% | 43% | 48% |
A purely objective ENSO probability forecast, based on regression, using as input the model predictions from the plume of dynamical and statistical forecasts shown in the ENSO Predictions Plume. Each of the forecasts is weighted equally. It is updated near or just after the middle of the month, using forecasts from the plume models that are run in the first half of the month. It does not use any human interpretation or judgment. This is updated on the third Thursday of the month.
| Season | La Niña | Neutral | El Niño |
|---|---|---|---|
| NDJ 2014 | 1% | 99% | ~0% |
| DJF 2014 | 3% | 96% | 1% |
| JFM 2014 | 4% | 92% | 4% |
| FMA 2014 | 5% | 84% | 11% |
| MAM 2014 | 5% | 74% | 21% |
| AMJ 2014 | 7% | 59% | 34% |
| MJJ 2014 | 10% | 48% | 42% |
| JJA 2014 | 8% | 44% | 48% |
| JAS 2014 | 9% | 43% | 48% |
The official CPC ENSO probability forecast, based on a consensus of CPC and IRI forecasters. It is updated during the first half of the month, in association with the official CPC ENSO Diagnostic Discussion. It is based on observational and predictive information from early in the month and from the previous month. It uses human judgment in addition to model output, while the forecast shown in the Model-Based Probabilistic ENSO Forecast relies solely on model output. This is updated on the second Thursday of every month.
| Season | La Niña | Neutral | El Niño |
|---|---|---|---|
| OND 2013 | 7% | 91% | 2% |
| NDJ 2014 | 9% | 86% | 5% |
| DJF 2014 | 9% | 82% | 9% |
| JFM 2014 | 10% | 78% | 12% |
| FMA 2014 | 10% | 74% | 16% |
| MAM 2014 | 11% | 67% | 22% |
| AMJ 2014 | 11% | 60% | 29% |
| MJJ 2014 | 12% | 55% | 33% |
| JJA 2014 | 12% | 52% | 36% |
The following graph and table show forecasts made by dynamical and statistical models for SST in the Nino 3.4 region for nine overlapping 3-month periods. Note that the expected skills of the models, based on historical performance, are not equal to one another. The skills also generally decrease as the lead time increases. Thirdly, forecasts made at some times of the year generally have higher skill than forecasts made at other times of the year--namely, they are better when made between June and December than when they are made between February and May. Differences among the forecasts of the models reflect both differences in model design, and actual uncertainty in the forecast of the possible future SST scenario.
You can highlight a specific model by hovering over it either on the chart or the legend. Selecting An item on the legend will toggle the visibility of the model on the page. You can also select DYN MODELS or STAT MODELS to toggle them all at once. Clicking on the "burger" menu above the legend will give you options to download the image or expand to full screen. If you have any feedback on this new feature, please let us know at webmaster@iri.columbia.edu.
| Seasons (2013-2014) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Model | |||||||||
| Dynamical models | |||||||||
| NCEP CFS version 2 | 0.1 | 0 | -0.1 | 0 | 0.2 | 0.3 | 0.4 | 0.5 | |
| NASA GMAO model | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | 0 | ||
| Japan Met. Agency model | 0 | 0.1 | 0.1 | 0.2 | 0.3 | ||||
| Scripps Inst. HCM | 0.3 | 0.4 | 0.5 | 0.6 | 0.7 | 0.7 | 0.7 | 0.8 | 0.9 |
| Lamont-Doherty model | -0.5 | -0.6 | -0.5 | -0.4 | -0.3 | -0.1 | 0.1 | 0.3 | 0.3 |
| POAMA (Austr) model | -0.1 | -0.1 | -0.1 | 0 | 0 | 0 | 0 | ||
| ECMWF model | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | ||||
| UKMO model | -0.2 | -0.3 | -0.4 | ||||||
| KMA (Korea) SNU model | 0.2 | 0.4 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.4 | 0.4 |
| ESSIC Intermed. Coupled model | -0.2 | -0.2 | -0.2 | -0.1 | 0 | 0.1 | 0.1 | 0.2 | 0.2 |
| COLA CCSM3 model | 0.7 | 0.9 | 1.1 | 1.3 | 1.5 | 1.5 | 1.3 | 1.2 | 1.1 |
| MÉTÉO FRANCE model | -0.1 | 0 | 0 | 0.1 | 0.2 | ||||
| Japan Frontier Coupled model | 0.2 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.4 | 0.5 | 0.5 |
| CSIR-IRI 3-model MME | -0.3 | -0.4 | -0.4 | -0.3 | -0.2 | ||||
| GFDL CM2.1 Coupled Climate model | 0.1 | 0.3 | 0.4 | 0.5 | 0.6 | 0.8 | 0.9 | 0.9 | 0.8 |
| Canadian Coupled Fcst Sys | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.3 | 0.4 | 0.5 | 0.5 |
| Average, dynamical models | 0 | 0 | 0.1 | 0.2 | 0.3 | 0.4 | 0.4 | 0.6 | 0.6 |
| Statistical models | |||||||||
| NCEP/CPC Markov model | -0.3 | -0.2 | -0.1 | 0 | 0.1 | 0.1 | 0.2 | 0.2 | 0.2 |
| NOAA/CDC Linear Inverse | -0.3 | -0.3 | -0.3 | -0.3 | -0.3 | -0.2 | -0.1 | -0.1 | 0 |
| NCEP/CPC Constructed Analog | -0.3 | -0.3 | -0.3 | -0.3 | -0.1 | 0.2 | 0.3 | 0.4 | 0.3 |
| NCEP/CPC Can Cor Anal | -0.5 | -0.5 | -0.4 | -0.2 | 0 | 0.2 | 0.3 | 0.5 | 0.5 |
| Landsea/Knaff CLIPER | 0 | 0 | 0 | 0 | 0.1 | 0.2 | 0.3 | 0.3 | 0.4 |
| Univ. BC Neural Network | -0.2 | -0.1 | -0.1 | 0 | 0.1 | 0.1 | 0.2 | 0.3 | 0.3 |
| FSU Regression | -0.2 | -0.1 | -0.1 | 0 | 0.2 | 0.5 | 0.7 | 0.9 | 0.8 |
| TDC – UCLA | -0.2 | -0.3 | -0.3 | -0.2 | -0.2 | -0.1 | 0 | 0.1 | 0.1 |
| Average, statistical models | -0.2 | -0.2 | -0.2 | -0.1 | 0 | 0.1 | 0.2 | 0.3 | 0.3 |
| Average, all models | -0.1 | 0 | 0 | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 0.5 |
Most of the set of dynamical and statistical model predictions issued during late October and early November 2013 predict neutral ENSO conditions through the rest of 2013 and into early 2014, with a warming tendency during northern spring and summer 2014. Development of weak El Nino conditions appears possible by the middle of 2014. In the most recent week, the SST anomaly in the Nino3.4 region was 0.0C. Based on the multi-model mean predictions, and the expected skill of the models by start time and lead time, the probabilities (X100) for La Nina, neutral and El Nino conditions (using -0.5C and 0.5C thresholds) over the coming 9 seasons are:
| Season | La Niña | Neutral | El Niño |
|---|---|---|---|
| NDJ 2014 | 1% | 99% | ~0% |
| DJF 2014 | 3% | 96% | 1% |
| JFM 2014 | 4% | 92% | 4% |
| FMA 2014 | 5% | 84% | 11% |
| MAM 2014 | 5% | 74% | 21% |
| AMJ 2014 | 7% | 59% | 34% |
| MJJ 2014 | 10% | 48% | 42% |
| JJA 2014 | 8% | 44% | 48% |
| JAS 2014 | 9% | 43% | 48% |
The following interactive plot shows the model forecasts issued not only from the current month (as in the plot above),
but also from the 21 months previous to this month. The observations are shown up to the most recently completed
3-month period. The plots allow comparison of plumes from the previous start times, or examination of the forecast
behavior of a given model over time.
Hovering over any single model will highlight that particular model in the chart.
Clicking a particular model will hide/show that model in the chart.
At the bottom of the plot, you can select which models to show in the chart:
all the models, the dynamical models only, or the statistical models only.
Only models producing forecasts on a monthly basis are included. This means that some models whose forecasts appear in the Experimental Long-Lead Forecast Bulletin (produced by COLA) do not appear in the table.
Once an IRI ENSO probability forecast has been published, the results stand even if a model reports an error and changes their data. When this happens we will update the plume with the model's correct values even though our forecast hasn't changed. What this means is that our forecast is always the same, but the underlying data may be different from what we based our forecast on.
The SST anomaly forecasts are for the 3-month periods shown, and are for the Nino 3.4 region (120-170W, 5N-5S). Often, the anomalies are provided directly in a graph or a table by the respective forecasting centers for the Nino 3.4 region. In some cases, however, they are given for 1-month periods, for 3-month periods that skip some of the periods in the above table, and/or only for a region (or regions) other than Nino 3.4. In these cases, the following means are used to obtain the needed anomalies for the table:
The anomalies shown are those with respect to the base period used to define the normals, which vary among the groups producing model forecasts. They have not been adjusted to anomalies with respect to a common base period. Discrepancies among the climatological SST resulting from differing base periods may be as high as a quarter of a degree C in the worst cases. Forecasters are encouraged to use the standard 1991-2020 period as the base period, or a period not very different from it.
The CPC ENSO forecast is released at 9am (Eastern Time) on the second Thursday of each month.
The IRI ENSO forecast is released on the 19th of each month. If the 19th falls on a weekend or holiday, it is released on the closest business day.
All data from this website is covered under the Creative Commons Attribution 4.0 License. When citing IRI ENSO images or data, please use "Images [or Data] provided by The International Research Institute for Climate and Society, Columbia University Climate School", with a link to https://iri.columbia.edu/ENSO.
The official CPC ENSO probability forecast, based on a consensus of CPC and IRI forecasters. It is updated during the first half of the month, in association with the official CPC ENSO Diagnostic Discussion. It is based on observational and predictive information from early in the month and from the previous month. It uses human judgment in addition to model output, while the forecast shown in Fig. 3 relies solely on model output. Figure 1 is updated on this page on the second Thursday of every month.
NOAA/CPC ENSO Forecast Graphic, courtesy of NOAA/CPC
×A purely objective ENSO probability forecast, based on regression, using as input the model predictions from the plume of dynamical and statistical forecasts shown in Fig. 4. Each of the forecasts is weighted equally. It is updated near or just after the middle of the month, using forecasts from the plume models that are run in the first half of the month. It does not use any human interpretation or judgment. Figure 3 is updated on the third Thursday of every month.
×Plume of forecasts of the Nino3.4 SST anomaly from dynamical and statistical models that are run during the first half of the month. A probability forecast is generated using all the models in Fig. 4, and is shown in Fig. 3. The average of the forecasts of the dynamical models is shown by the thick yellow line, and of the statistical models by the thick green line. The average of the four models run at the NOAA Climate Prediction center (CPC) is shown by the thick pink line. This figure is updated on the third Thursday of every month. Because forecasts from some models of Fig. 4 are not yet available when the official CPC ENSO probability forecast (Fig. 1) is made, the official forecast uses the previous month's Fig. 4 as one of its inputs, which is shown in the CPC ENSO Diagnostic Discussion.
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