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October 2022 Quick Look

Published: October 19, 2022

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)

In mid-October, sea surface temperatures in the central-eastern equatorial Pacific remain below-average. Key oceanic and atmospheric variables have remained consistent with La Niña conditions. A CPC La Niña Advisory still remains in place for October 2022. A large majority of the models in the plume predict SSTs to remain below-normal at the level of a La Niña until at least Jan-Mar 2023. Similar to the most-recent official CPC ENSO Outlook issued on October 13, 2022, the objective model-based ENSO outlook forecasts a continuation of the La Niña event with high probability during Nov-Jan, Dec-Feb, and Jan-Mar 2023. Based on objective ENSO forecasts, La Niña is expected to transition into ENSO-neutral during Feb-Apr 2023, which remains the most likely category thereafter.

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.

Historically Speaking

    El Niño and La Niña events tend to develop during the period Apr-Jun and they
  • Tend to reach their maximum strength during October - February
  • Typically persist for 9-12 months, though occasionally persisting for up to 2 years
  • Typically recur every 2 to 7 years

ENSO Forecast

CPC ENSO Update

Published: October 13, 2022

El Niño/Southern Oscillation (ENSO) Diagnostic Discussion issued by the Climate Prediction Center/NCEP/NWS

ENSO Alert System Status: La Niña Advisory

Synopsis: There is a 75% chance of La Niña during the Northern Hemisphere winter (December-February) 2022-23, with a 54% chance for ENSO-neutral in February-April 2023.

Below-average sea surface temperatures (SSTs) continued across the central and eastern equatorial Pacific Ocean during September (Fig. 1). Most of the Niño indices decreased during the past month, with the latest weekly index values spanning -0.8ºC to -1.6ºC (Fig. 2). For the last couple months, negative subsurface temperature anomalies remained mostly unchanged (Fig. 3), reflecting the persistence of below-average temperatures across the eastern Pacific Ocean (Fig. 4). Low-level easterly wind anomalies and upper-level westerly wind anomalies prevailed across most of the equatorial Pacific.  Convection was suppressed over the western and central tropical Pacific and was enhanced over Indonesia (Fig. 5). Overall, the coupled ocean-atmosphere system continued to reflect La Niña.

The most recent IRI plume forecast of the Niño-3.4 SST index indicates La Niña will persist into the Northern Hemisphere winter 2022-23, and then transition to ENSO-neutral in January-March 2023 (Fig. 6). The forecaster consensus for this month favors a slightly later transition to ENSO-neutral, during February-April 2023, which is consistent with the latest North American Multi-Model Ensemble (NMME).  However, predicting the timing of transitions is challenging, and there continues to be uncertainty over how long La Niña may last.  In summary, there is a 75% chance of La Niña during the Northern Hemisphere winter (December-February) 2022-23, with a 54% chance for ENSO-neutral in February-April 2023 (Fig. 7).

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). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 10 November 2022. 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
SON 100 0 0
OND 95 5 0
NDJ 86 14 0
DJF 75 25 0
JFM 59 39 2
FMA 43 54 3
MAM 26 67 7
AMJ 16 69 15
MJJ 12 62 26

IRI ENSO Forecast

IRI Technical ENSO Update

Published: October 19, 2022

Note: The SST anomalies cited below refer to the OISSTv2 SST data set, and not ERSSTv5. OISSTv2 is often used for real-time analysis and model initialization, while ERSSTv5 is used for retrospective official ENSO diagnosis because it is more homogeneous over time, allowing for more accurate comparisons among ENSO events that are years apart. These two products may differ, particularly during ENSO events. The difference between the two datasets may be as much as 0.5 °C. Additionally in some years, the ERSSTv5 may tend to be cooler than OISSTv2 in the context of warming trends, because ERSSTv5 is expressed relative to a base period that is updated every 5 years, while the base period of OISSTv2 is updated every 10 years. In February 2021, both datasets were updated to reflect the 1991-2020 climatology period.

Recent and Current Conditions

The SST anomaly for NINO3.4 during the Jun-Aug season was -0.76 °C, and for the month of August it was -0.98 °C. The most recent weekly (14 Sep 2022) anomaly in the NINO3.4 region was -0.9 °C, indicating persistent weak La Niña conditions. 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 colder.

Many of the key atmospheric variables remain indicative of La Niña conditions, such as the traditional and equatorial Southern Oscillation Indices, which remained positive during August 2022. The low-level easterly winds are above normal across the central-eastern Pacific, while upper-level wind anomalies remain westerly across the tropical Pacific. Anomalously dry conditions have been observed over the central and western Pacific Ocean (west of the Date Line). Across the equatorial Pacific Ocean, subsurface temperatures are above average in the western Pacific. Negative subsurface temperatures are evident near the surface and at depth (100 to 150 meters) in the central and eastern Pacific.

In summary, tropical Pacific atmospheric and oceanic conditions remain consistent with La Niña and a La Niña advisory is still in place.

Expected Conditions

Note – Only models that produce a new ENSO prediction every month are considered in this statement.

What is the outlook for the ENSO status going forward? El Niño/Southern Oscillation (ENSO) Diagnostic Discussion issued on 13 October 2022 by the Climate Prediction Center/NCEP/NWS indicates a continuation of the current La Niña event.

The latest set of 24 models (17 Dynamical and 7 Statistical)  of ENSO predictions for mid-October is now available in the IRI ENSO prediction plume. These are used to assess the probabilities of the three possible ENSO conditions by using the average value of the NINO3.4 SST anomaly predictions from all models in the plume, equally weighted. A standard Gaussian error is imposed over that average forecast, and its width is 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.

A large number of the models in the plume predict SSTs to remain below-normal at the level of a weak La Niña until Jan-Mar 2023. In particular, the chances of La Niña during Nov-Jan are 84%, 72% for Dec-Feb, and 55% for Jan-Mar, while those of the ENSO-neutral category are 16%, 28%, and 44% respectively. The forecast shows a very high probability during boreal winter 2023 of the current event becoming the first triple-dip La Niña of the 21st century (two others were 1974-1976 and 1999-2001). ENSO-neutral becomes the most likely category in Feb-Apr 2023 (61%), which remains the case for rest of the forecast period through Jun-Aug 2023. The likelihood of El Niño remains very low through most of the forecast period, but rises to 36% in Jun-Aug 2023. A plot of the probabilities summarizes the forecast evolution. The climatological probabilities for La Niña, ENSO-neutral, and El Niño conditions vary seasonally, and are shown in a table at the bottom of this page for each 3-month season.

Caution is advised in interpreting the forecast distribution from the Gaussian standard error as the actual probabilities, due to differing biases and performance of the different models. 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. At longer leads, the skill of the models degrades, and uncertainty in skill must be convolved with the uncertainties from initial conditions and differing model physics, which leads 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.

In summary, the probabilities derived from the 24 models in the IRI ENSO forecast plume indicate a preference for the continuation of the La Niña event until Jan-Mar 2023 with moderate chances (55%), while ENSO-neutral conditions are most likely thereafter. The likelihood of El Niño development remains very low for most of the forecast period (5% in boreal spring), but increases to 36% in boreal summer.

A caution regarding the model-based ENSO plume predictions released mid-month, is that factors such as known specific model biases and recent changes in the tropical Pacific that the models may have missed, are not considered. This approach is purely objective. Those issues are taken into account in the official outlooks, which are generated and issued early in the month by CPC, and which will include some human judgment in combination with the model guidance.


IRI ENSO Forecast Histogram Image
Season La Niña Neutral El Niño
OND 93 7 0
NDJ 84 16 0
DJF 72 28 0
JFM 55 44 1
FMA 36 61 3
MAM 21 74 5
AMJ 13 74 13
MJJ 12 62 26
JJA 12 52 36

ENSO Forecast

IRI Model-Based Probabilistic ENSO Forecast

Published: October 19, 2022

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.


IRI ENSO Forecast Histogram Image


Season La Niña Neutral El Niño
OND 93 7 0
NDJ 84 16 0
DJF 72 28 0
JFM 55 44 1
FMA 36 61 3
MAM 21 74 5
AMJ 13 74 13
MJJ 12 62 26
JJA 12 52 36

ENSO Forecast

CPC Official Probabilistic ENSO Forecast

Published: October 13, 2022

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.


NOAA?CPC ENSO Forecast Image
NOAA/CPC ENSO Forecast Graphic, courtesy of NOAA/CPC

Season La Niña Neutral El Niño
SON 100 0 0
OND 95 5 0
NDJ 86 14 0
DJF 75 25 0
JFM 59 39 2
FMA 43 54 3
MAM 26 67 7
AMJ 16 69 15
MJJ 12 62 26

ENSO Forecast

IRI ENSO Predictions Plume

Published: October 19, 2022

Note on interpreting model forecasts

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.

Interactive Chart

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.


List of Models Used


Forecast SST Anomalies (deg C) in the Nino 3.4 Region

Seasons (2022 – 2023)
Model OND NDJ DJF JFM FMA MAM AMJ MJJ JJA
Dynamical Models
AUS-ACCESS -0.87 -0.70 -0.40 -0.10
BCC_CSM11m -0.40 0.24 0.83 1.23 1.43 1.55 1.72 1.96 2.21
CMC CANSIP -0.87 -0.89 -0.76 -0.51 -0.26 -0.08 0.12 0.35 0.61
COLA CCSM4 -0.97 -1.01 -0.99 -0.77 -0.43 -0.11 0.09 0.29 0.53
CS-IRI-MM -1.01 -0.97 -0.82 -0.57 -0.27 0.06
ECMWF -0.68 -0.57 -0.45 -0.28 -0.05
GFDL SPEAR -0.54 -0.44 -0.30 -0.10 0.10 0.31 0.49 0.69 0.83
IOCAS ICM -0.93 -1.08 -1.33 -1.40 -1.35 -1.24 -1.18 -1.14 -1.09
JMA -1.01 -0.99 -0.84 -0.64 -0.39
KMA -0.89 -0.91 -0.84 -0.63 -0.33
LDEO -0.68 -0.54 -0.36 -0.25 -0.24 -0.29 -0.32 -0.29 -0.26
MetFRANCE -1.16 -1.10 -1.02 -0.79 -0.56 -0.39 -0.13
NASA GMAO -1.83 -1.82 -1.30 -0.68 -0.21 0.09 0.30
NCEP CFSv2 -1.25 -1.16 -0.92 -0.61 -0.28 -0.01 0.21
SAUDI-KAU -0.67 -0.36 -0.13 -0.01 0.07 0.12 0.13 0.12 0.15
SINTEX-F -0.00 0.05 0.07 0.07 0.10 0.15 0.21 0.28 0.32
UKMO -1.35 -1.29 -1.02 -0.64
Average, Dynamical models -0.888 -0.797 -0.622 -0.393 -0.178 0.013 0.150 0.282 0.414
Statistical Models
BCC_RZDM -1.13 -1.17 -1.15 -1.01 -0.70 -0.34 0.07 0.38 0.56
CPC CA -1.45 -1.42 -1.18 -0.90 -0.53 -0.24 0.07 0.32 0.55
CPC MRKOV -1.39 -1.20 -0.95 -0.70 -0.49 -0.28 -0.08 0.09 0.22
CSU CLIPR -0.77 -0.69 -0.61 -0.53 -0.24 0.04 0.33 0.52 0.71
IAP-NN -1.40 -1.46 -1.42 -1.29 -1.10 -0.88 -0.68 -0.49 -0.34
NTU CODA -1.29 -1.45 -1.53 -1.29 -1.14 -0.94 -0.64 -0.37 -0.27
UCLA-TCD -1.18 -1.20 -1.15 -1.04 -0.89 -0.74 -0.61 -0.56 -0.61
Average, Statistical models -1.231 -1.226 -1.141 -0.966 -0.727 -0.482 -0.219 -0.015 0.117
Average, All models -0.988 -0.922 -0.774 -0.560 -0.353 -0.169 0.006 0.143 0.276

Discussion of Current Forecasts

For three seasons (Nov-Jan, Dec-Feb, and Jan-Mar), all statistical and several dynamical models indicate a continuation of the current La Niña event. Overall, there is a high chance for La Niña to persist during boreal winter (72% chance in Dec-Feb 2023), and to transition to ENSO-neutral in Feb-Apr (61% chance) and remain dominant during rest of the forecast period. The probabilities for El Niño conditions remain very low during most of the forecast period (5% during boreal spring), but increasing to 36% in boreal summer. Based on the multi-model mean prediction, and the expected skill of the models by start time and lead time, the probabilities (X100) for La Niña, ENSO-neutral and El Niño conditions (using -0.5 °C and 0.5 °C thresholds) over the coming 9 seasons are:

Season La Niña Neutral El Niño
OND 93 7 0
NDJ 84 16 0
DJF 72 28 0
JFM 55 44 1
FMA 36 61 3
MAM 21 74 5
AMJ 13 74 13
MJJ 12 62 26
JJA 12 52 36

Summary of forecasts issued over last 22 months

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.


Notes on the data 

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:

  • Temporal averaging
  • Linear temporal interpolation
  • Visual averaging of values on a contoured map

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.

Historical SST Anomalies Image

ENSO Forecast

Forecast Probability Distribution Based on the IRI ENSO Prediction Plume

Published: October 19, 2022


The plots on this page show predictions of seasonal (3-month average) sea surface temperature (SST) anomaly in the Niño3.4 region in the east-central tropical Pacific (5°N-5°S, 120°-170°W), covering the nine overlapping seasons beginning with the current month. The predictions are based on the large (20+) set of dynamical and statistical models in the plume of model ENSO predictions.


  • Model Based Prediction Percentiles Image

    Figure 5

    Predictions of ENSO are probabilistic. The ensemble mean prediction is only a best single guess. On either side of that prediction, there is a substantial uncertainty distribution, or error tolerance. The second plot (Figure 2) shows the estimated probability distribution of the predictions, showing a set of percentiles within that distribution for each lead time. The distribution is modeled as a normal (Gaussian) distribution, so that the overall mean forecast represents the center, or 50 percentile, in the distribution. The overall mean is formed using equal weighting among all models. On either side, other percentile values are shown symmetrically, ranging from 1 to 99 and including some intermediate percentiles (5 and 95, 15 and 85, and 25 and 75). The plot enables a user to estimate the probability of the Niño3.4 SST anomaly to be greater or less than some critical value, or within some interval. If, for example, the 85 percentile falls at 1.8° C above average, the probability of the SST exceeding 1.8° C can be estimated at 15%. Probabilities for exceeding or not exceeding values not exactly on percentile line can be roughly interpolated by eye. The overall width of the probability distribution is derived from the historical skill of the hindcasts of the models, from 1982 to present, for the specific forecast start time and lead time. This method of defining the probability distribution represents one of two general approaches, the other approach being a direct counting of ensemble members within each of the percentile bands. This second approach assumes that the ensemble spreads of the models are true representations of the uncertainty. Individual model spreads have often been found to be somwehate narrower than they should be, although in multi-model ensembles this tendency has been shown to be milder or even eliminated.

  • Model Based Prediction Distribution Image

    Figure 6

    Figure 6, sometimes called a spaghetti diagram, shows synthetically generated prediction scenarios that are equally likely. Here, 100 scenarios are shown; any number can be generated for such a diagram. Each scenario is produced using a random number generator, combined with knowledge of the mean forecast and its uncertainty, as well as the amount of persistence of anomalies. The degree of persistence of anomalies is based on the correlation of prediction errors from one lead time to another. In other words, the individual lines are designed to show the correct amount of persistence as expected in nature, rather than jumping around more randomly from one lead time to the next. The uncertainty and persistence statistics are based on the set of 7 NMME (North American Multimodel Ensemble) models, as it is assumed that these statistics are approximately applicable to all of the models. Sometimes the “spaghetti density” may appear asymmetric about the mean of all the forecasts or outside of the 85 and 15 percentile lines. This is purely sampling variability, and would not occur if many thousands of such lines were plotted. But with that many lines, most of the plot would be too crowded to get a sense of the behavior of the lines near the center of the distribution. The main purpose of the diagram is to serve users who want to assess realistic individual scenarios of ENSO behavior rather than statistical summaries of the forecast like the percentiles shown in the second plot.

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.