The three sources we rely on for ENSO news are Australia's Bureau of "Japan Agency for Marine-Earth Science and Technology" (JAMSTEC)
JAMSTEC defined the modoki flavor of El Niño which arises in the central rather than the eastern Pacific with the Japanese word meaning "similar but different", handy for dropping casually into conversation at the Thursday afternoon salon.
First, a note on terminology for normal people who don't obsess about this stuff:
- ENSO = the El Niño/Southern Oscillation
- ENSO Neutral = the ocean surface temperature anomaly in the ENSO 3.4 region is between +0.5°C and -0.5°C.
- El Niño/La Niña conditions exist when the anomaly is greater than (Niño) or less than (Niña) the half-degree cut-off for neutral.
- A full blown El Niño/La Niña is declared when the conditions persist for three overlapping three-month periods i.e. five consecutive months.
From Columbia University/International Research Institute for Climate and Society, May 19:
Published: May 19, 2026
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)
As of mid-May 2026, the equatorial Pacific is rapidly transitioning into El Niño conditions. While monthly SST anomalies remain near the borderline El Niño threshold, weekly values have surged well above it, with the last three weekly pentads firmly reaching +0.9 °C in the Niño3.4 region. This sharp warming strongly indicates that the currently near neutral seasonal averages will rise substantially in the coming months, marking a clear shift from ENSO neutral to El Niño conditions. The latest CCSR/IRI ENSO plume forecast further supports this evolution, assigning a 98% probability to El Niño during May–July 2026 compared to only 2% for continued neutrality. El Niño conditions are then likely to persist through the remainder of 2026, with forecast probabilities consistently maintained within a remarkably high and narrow 97–98% range....
....MUCH MORE
One of the many charts and graphs, the plume of predictions, both statistical and dynamical:
Though the two averages (thick lines) are quite high, the outliers, above 2.5°C anomaly and even a few forecasting a +3.0°C anomaly are among the highest in years.
Finally, although all three sites are excellent, and NOAA in the U.S. is the go-to for many who are attempting the dark arts of layering one complex/chaotic system, financial markets, on top of another complex/chaotic system ENSO/weather, it is only with JAMSTEC that you also get the:
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