Thursday, October 23, 2014

Checking ENSO forecasts

I few days ago I commented here on the latest NOAA ENSO advisory:
""ENSO-neutral conditions continue.*
Positive equatorial sea surface temperature (SST) anomalies continue across most of the Pacific Ocean.
El Niño is favored to begin in the next 1-2 months and last into the Northern Hemisphere spring 2015.*""

I repeated this at WUWT, and someone said, but they have been saying that all year. So I ran a check on ENSO predictions.

The NOAA Climate Prediction Center posts a monthly series of CDBs (Diagnostic Bulletins) here. They are full of graphs and useful information. They include compilations of ENSO predictions (Nino3.4), nicely graphed by IRI. I downloaded the plots for each month of 2014, and overlaid with the observed value from this file.

It's an active plot, so you can click through the months. The year started out with a dip, mostly unforeseen. This coincided with the global cool in February. There was then a underpredicted recovery, and since then there has been a tendency for the index to be below predictions, esp June and July.

CPC warns that only modest predictive skill is to be expected, and that is fortified by the spread in forecasts. The index does indeed seem to move beyond the predicted range rather easily. It's not always overpredicted, though.

Here is the active plot. Just click the top buttons to cycle through the 9 months. The thick black overlay line are the monthly observations.


You'll see some minor discrepancies at the start. I don't think this is bad graphing - I assume minor changes to Nino3.4 between the monthly report and now. It looks like maybe a scaling error, but I don't think it is. I should note that I'm plotting the monthly value, while the foecasts are for three minth averages. I wanted to match the initial, which is one month. But Nino3.4 does not have much monthly noise, so I don't think averages would look much different.


  1. Learn from ENSO by looking at the past. Not even considering synchronization of El Nino conditions with the beginning of the year, there is a significant causal correlation connecting QBO, TSI, and likely the Chandler wobble to ENSO

    The equatorial Pacific waters clearly have a natural resonance of about a 4.25 year period which is pumped by the wind shear forces of the descending QBO, aided by the periodic thermal charging/discharging due to TSI anomalies, and assisted by the inertial changes associated with the Chandler wobble.

    The rest is the seasonal push provided the annual solar variation.

    Very little of this is random or chaotic, contrary to what the deniers at Climate Etc and WUWT will continue to assert.

    1. Web,
      If you have monthly predictions, I could add them to the plot. I'll probably re-do this check from time to time.

    2. Sounds good. I am thinking that, even though the results are striking, that this is still a work in progress and so it should be modified if needed. The quality of the fit is still dependent on how well I can capture the behavior of QBO and TSI and then adjusting the scale factors and any phase relationships that exist.

  2. Nick, you might want to look at troyca's posts on the inability of this approach to validate.

    Here's the link to part 3. The others are included in this post:

    1. I have a model called CSALT that uses a multiple regression approach to model the pause, partially using the ENSO signal as a compensating factor. It works perfectly well.

      I am not impressed with Troy Masters and most of those that are working the problem. They don't seem to understand the fat-tailed diffusion mechanisms of heat (and CO2 for that matter) AT ALL. Not even worth trying to follow what he is doing as it will lead one down a deep rabbit hole.

  3. A bunch of armchair weather prognosticators are going at it
    Bastardi thinks that the solar activity is some sort of factor. He is seeing a sharp recent downward spike in the SOI

    I tried to parameterize the TSI and applied it to the SOI model

  4. My submitted paper on ENSO model is on ARXIV

    Forget the red noise models. I assert that ENSO, and thus the earth's decadal variability, is close to deterministic and largely predictable.