On the second Thursday of every month, NOAA issues its analysis of the status of ENSO. This includes determining the Alert System Status. Although the current status remains the same i.e. La Nina Advisory, the forecast has again been adjusted slightly from the prior month. The IRI analysis suggests it could be slightly later than it appeared last month. Also, the probability that it will extend into the winter is much higher. So what I anticipated as being a three-peat now looks to be a certainty. There is some disagreement on when this La Nina will end with the best guess being perhaps February or March.
But I actually see no sign of it starting to happen. But all the meteorologists agree that it will. Could they all be wrong?
I also include some interesting graphics that show the impact of the combination of La Nina and what NOAA calls “trend” which is a combination of Global Warming and long cycles. I find them interesting. The IOD is about over so the weather in the Indian Ocean should return to something more like normal. The three phases of ENSO basically impact the entire world. It does appear that this third La Nina winter may be quite different from last year. But I will address that when NOAA issues their Seasonal Outlook for the U.S. and when I publish the JAMSTEC world outlook which I already have and I will probably publish it very soon.
| Announcement: We now publish a daily weather report that addresses both short-term and intermediate-term weather issues and you can find it at econcurrents.com. To return to this article just hit the return arrow at the upper left corner of your screen |
CLIMATE PREDICTION CENTER ENSO DISCUSSION
| The second paragraph is what is important: “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). 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).” |
| We now provide a lot of additional detail. The detail is for those who will find it interesting. If your main interest was in learning what the current Status of ENSO was and how long the current state might last, you may not need to read the remainder of this article as that information has already been presented above. If you are interested in how reliable the conclusion is and why one might accept the conclusion or be skeptical about the conclusion, continue to read. |
IRI CPC ENSO STATE Probability Distribution (IRI stands for the International Research Institute for Climate and Society)
Here are the new forecast probabilities. This information is released twice a month and the first release is based on a survey of Meteorologists, the second is based on model results. The probabilities are for three-month periods e.g. SON stands for September/October/November.
| Notice for JFM 2023 the probability of La Nina is higher than the probability for ENSO Neutral. But for FMA the probability for ENSO Neutral slightly exceeds that for La Nina. So maybe March is when the ocean conditions will be consistent with ENSO Neutral but the impact on our weather may lag a month or so. So we really seem to be looking at La Nina into Spring. This is a very slight change from the analysis made last month which is a slight change from the analysis made the month before. Is that a trend? |
Analysis of the current and prior first and second Forecasts in each month.
IRI actually makes two forecasts a month. The first which is based on a survey of meteorologists is the one that NOAA relies on when they prepare their seasonal outlook. The second is a summary of the forecasts made by a set of computer models.
Here are the last two reports from IRI
But look at this.
| Is the NOAA Climate Prediction Center (CPC) now saying that the first set of probabilities is provided by CPC and only the second set is provided by IRI? I have gone on the record that there is a coordination problem between CPC and IRI and I might have said that IRI should be fired. I am not sure I have said that but I certainly have thought it. It looks like the CPC is trying to provide a little more oversight of the work of IRI which is a contractor to the NOAA CPC. |
Recent ENSO History.
| The three-month average of Nino3.4 readings becomes the Oceanic Niño Index or ONI. So that is an official number subject to change when they update the climatology. What you can see here clearly is the duration of the three phases of ENSO. So we have been in La Nina since JAS 2020. La Nina rarely goes beyond two years. This one looks like it will. Hence “Three-peat”. You can access the full history Here https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php Later I show an interesting graphic that appears in the Blog post written by Emily Becker which addresses the question of how often a re-peat becomes a Three-peat. There are reasons why it is unlikely but with Global Warming, history may not be as good a guide as usual. ENSO is something like a cycle. Could the length of that cycle be changing? So that is a question that some are thinking about. At first glance, it would seem that La Nina would be rarer rather than more frequent since it is associated with cool water in the Eastern Pacific. But the obvious does not always turn out to be correct. We have now recorded another 3-month ONI that was in La Nina territory. I just noticed there was a long string of La Nina ONI’s in 2010 through 2012 but there was one neutral reading that broke the string. But we have the same string in 2021 so I guess the stray neutral readings do not count. |
What Does the NOAA Proprietary ENSO Model Forecast?
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| The above does not auto-update but you can click HERE. https://www.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/images3/nino34SeaadjPDFSPRDC.gif NOAA relies more on the IRI Forecast. But perhaps this model is now showing that we may become ENSO Neutral (Nino 3.4 Index great than -0.5C) for next Spring or even the second half of Winter. It is showing it happening later than it had been showing it. If you look carefully for the mean of the various computer runs it intersects -0.5C in DJF 2022-2023. So that is basically saying that La Nina will end during the Winter not after Winter. But the latest model runs if I am able to see that line on the graph suggests considerably later. It is difficult to sort it out as the situation is dynamic. |
And what does JAMSTEC have to say?
| There are a bunch of different model results shown. The thicker lines are averages of different groups of model results. They seem to show that the Nino 3.4 index goes above the -0.5C threshold in January which is sooner than many other models. But some of the model results show La Nina lasting longer. Notice that the JAMSTEC forecast shows a transition to El Nino by the Summer of 2023. More on that when I publish an article on the JAMSTEC forecast. |
And BOM? (Australian Bureau of Meteorology
| BOM has a different cut-off for La Nina than other meteorological agencies but they sort of agree with JAMSTEC rather than the U.S. NOAA CPC. |
What do Other Meteorological Agencies Say
I do not have the time or resources to check what all of the various meteorological agencies have to say about this. NOAA publishes (or is it IRI) what they call a plume of forecasts from many models not just those operated by the U.S. Last month those models seemed to show that ENSO Neutral with a strong bias towards La Nina was most likely. By a strong bias, I mean the forecast was for Nino 3.4 to be in the lower end of the ENSO neutral range. But the updated version of this “plume” will be published with the second IRI report so I do not have it now. But I do have a report from the Australian Meteorological agency (BOM) which shows a subset of models.
Australian BOM
| What I am showing here are forecast for January of 2023 and March of 2023. These are well-respected models. And using the U.S. threshold of -0.5 C in January of 2023, two models show that we are barely out of La Nina and into ENSO Neutral but by March they all show that we will be in ENSO Neutral. HERE is the link for this report and other ENSO information from BOM. |
Looking at Actual Current Conditions.
NOAA reports some derived data that describes the current situation and a forecast. But what if we want to form our own opinion? After all, meteorologists are looking at the actual current situation and making predictions.
This shows the current actual situation for the surface of oceans.
| Notice the cool water is almost all south of the Equator but the pattern extends to the west more than usual. To update this graphic click https://psl.noaa.gov/map/images/sst/sst.daily.anom.gif |
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Putting the historical information in motion (Updates can be found HERE.
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Where is ENSO Measured?
You can mentally superimpose the Nino 3.4 area shown encompassing part of the yellow and part of the red areas in the above map and you can see that it is cool in the Nino 3.4 area especially South of the Equator. That is an oddity of this La Nina that is both westerly displaced and focused mostly south of the Equator. There is not much discussion of that and how that might impact our weather. It certainly explains why the NINO 3.4 Index is still in La Nina territory but warmer than last month.
One can also see that we remain in PDO-(Neg).
How About the Future?
ENSO is measured at the surface of the ocean because it is the surface that interacts with the atmosphere. But the surface changes over time so we pay a lot of attention to the subsurface. Here we are just looking at the Equator but from the surface down to 450 meters. And we are looking at the temperature anomalies (deviations from normal this time of year at the given depth and longitude). The Nino 3.4 Index is measured at the surface but the subsurface may become the future surface. There is anomalously cool water almost everywhere on the surface.
Below is what it looks like now. Does it look like it will soon be other than cool? It is complicated because we are looking at anomalies not absolute temperatures and we are only looking at a cross-section at the Equator when the Nino 3.4 Area extends five degrees north and south of the Equator but there is only so much information that can be presented in one graphic. Sea Surface Temperature Anomalies are only one component of ENSO but probably the most important component and La Nina is relative to SSTA is defined as -0.5C or colder.
Off to the west, the warm Indo-Pacific Warm Pool has receded from prior months but it is quite intense with maximum anomalies of 3 degrees Celsius (and small areas of +4 C). And we must remember that these anomalies are calculated based on the seasonal norms for water at that depth. So three degrees warmer than usual does not mean it is warmer than the water at the surface. So it will not automatically rise.
Mapping the details. (Cross-Section along the Equator)
The data is a five-day average centered on the date shown.
Here is a version from a little over a month ago.
| All I see is a lot of cold water (what is shown is anomalies compared to climatology for location and time of year. I am not showing more than one of the prior versions this time. But the above is clearly la Nina and the warm IndoPacific Warm Pool shows no indication of moving east to replace the cool water that defines a La Nina. The cool anomaly is mainly south of the Equator (can not see that in the above graphic) and it extends far to the west (which you can see) making it what the Japanese call a Modoki. |
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Another way to look at the same information
| There is only a slight indication that the Eastern Pacific is warming. In the above, the anomalies from the surface down to 300 meters are added together. It is now a tad warmer than two weeks ago. |
Are the changes significant? We need to look at additional information.
Another way of looking at the situation is the impact of the Oceanic Kelvin Waves.
What is below explains a lot.
We described Oceanic Kelvin Waves in the article some months ago but let’s just say they are near-surface waves confined to the Equator which can move warm water east and help end a La Nina. The downwelling phase of such a wave is shown in red and the upwelling phase is shown in blue. The recent Kelvin Wave made it look more likely that we would transfer to ENSO Neutral. But it turned out to be a fairly weak Kelvin Wave not followed by another one although we might see one forming in this graphic. We might but we do not.
| The onset and evolution of the recent Kelvin Wave explain most of the changes in the probabilities from one release to the next so I think the Meteorologists may not have been paying as careful attention to this as they might have. You have to look at the Hovmoller carefully since it is showing things over time. The dates are shown. And we are mostly interested in what is currently taking place between 170W and 120W and what we can expect to happen as the waves progress to the east. There are no signs yet of another Kelvin Wave. |
Looking at the Wind Anomalies. This is another way to try to understand what is happening and this is another Hovmoller chart. I am pretty sure they used to create these charts with a plotter and every day the roll would unwind and there was one more day’s worth of data added. The format remains and it still works pretty well.
| This is a Hovmoller graphic. It is sort of what comes off of a plotter so the most recent information is at the bottom and the earlier information is at the top. Easterlies tend to be associated with La NIna since the Warm water in the IndoPacific Warm Pool can not easily move east. There is no sign of the Easterlies weakening. |
| My conclusion is we do not know yet when this La Nina will be over if ever. I take that back, La Nina can not persist forever. |
From the NOAA ENSO Blog
A good resource is the posts by Emily Becker. I have extracted some of the graphics but you can click on the below to read her full post or click here
There has been an interesting graphic for some months now in the NOAA ENSO BLOG which was written by Emily Becker. All La Ninas since 1950 which had a double-dip are shown. The black line is our current La Nina.
She has a new graphic this month.
I am not showing the graphics from the prior months since the current graphic includes all the information from prior months.
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| The black line is the current La Nina. It no longer looks like it is moving toward the ENSO Neutral Range. Is it ever planning to? |
But here are two additional graphics from Emily’s article.
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| These are not the official forecasts for Nov – Jan but what you would get if you only considered that we will be in La Nina and what the trend is. NOAA is a bit coy about the trend. For sure it includes Global Warming but presumable includes all other factors such as the state of the PDO and AMO. I live in NM so those two factors shown in the graphic above result in slight drying and warming everywhere in the state. Surprisingly Colorado gets wetter but warmer and the Northwest is wetter and Texas and to the east including Florida is dryer. The methodology is explained in this article. One can argue with the methodology. For the short term as in this Nov -Jan it is probably pretty reliable. Other factors will impact the outlook and the actuals but the above is a good start. |
What about the Indian Ocean Dipole (IOD)?
| The index is calculated as the monthly difference between the western (10°S-10°N, 50°-70°E) (WTIO) and eastern Indian Ocean (10°S-0°, 90°-108°E) (SETIO) sea surface temperature departures from average. |
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Australia BOM IOD forecast
And JAMSTEC
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| The IOD seems to be about over so I am not going to provide a discussion of the impacts of a negative IOD |
