(Super) El Niño 2026-27

[Grand Poo Bah]

Here's a chart of the last several El Ninos. This is pretty fascinating stuff.

 

[Atlantic]

Oh! I forgot about the TROPICAL thread. Thank you very much!

No problem! I feel like I am the one keeping the tropical area alive, so I saw that it is a U.S. threat, so I pulled the trigger on a thread.

If you need a thread, all you have to do is ask my friend

 

[Atlantic]

Here's a chart of the last several El Ninos. This is pretty fascinating stuff.

View attachment 54675

So we are already ahead of 1997-98, and we are nearly record breaking, almost outpacing the highest value from the 1982-83 event?

That’s interesting to say the least.

 

[WeathermanLeprechaun]

This is me right now....

 

[N0mz]

This is pure speculation and conjecture, because admittedly I am not strong on teleconnections. Wouldn’t a warmer background state like @Grand Poo Bah alluded to in his great post, actually dramatically lessen the chances we get strong/historic La Niñas such as 73-74, 2011, 1956, 1917 etc?

I’m not saying La Ninas won’t exist anymore, I’m just saying that when they do occur, they’re dealing with a much warmer average state than they were in those dates I listed. Which would in turn lessen their relative strength?

Regardless of your opinions, and again this is conjecture, it does seem like there is a trend of our El Niños are stronger when they occur and our average La Ninas are weaker when they do occur.

Without sounding like a certain infamous poster, this would have some impact on tornado seasons. I don’t think it’s coincidence that some of our biggest outbreaks on record occurred during very intense/historic La Ninas.

I think there’s been some substantial discussion regarding this general topic in the world of climatology. I’m not strong on it either, so take it with a grain of salt, but I recall hearing that the definition of what a La Niña/El Niño is is in the process of changing due to warmer anomalies being present in the world’s oceans in general right now. Since there’s a warmer baseline temperature to the oceans nowadays than there was just a couple decades ago, IIRC this statistically skews El Niños nowadays to be stronger than they “really are” although I do question this line of logic in a lot of ways. Again, not strong in this topic in the slightest, so I could be totally off the mark here. On the surface, I’d be inclined to believe that Niños would genuinely be stronger from SST rise, but more research is definitely needed.

Rising temperature baselines and ENSO (and other teleconnections) have been discussed in decent depth. The classic method for tracking ENSO, the Oceanic Niño Index (ONI), is a basic SST departure from climatology in the Niño 3.4 region. In February 2026, the CPC adopted the Relative Oceanic Niño Index (RONI), which compares the Niño 3.4 region with global tropical ocean temperatures and tracks the difference between them. The difference is then adjusted so that the historical variability matches the classic ONI measurement. Global tropical ocean temperatures provide a better indication of the ocean's baseline state and respond to climate change much more quickly. It is important to note that RONI does not simply subtract global SST warming from the classic ONI measurement. Since the tropics are still somewhat dynamic, the ONI-RONI spread can range from near zero (0.1 °C in JAS 2022 and a couple of times in 2018) to nearly 1 °C (0.8 °C in FMA-MAM 2024). See more at https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/announcement.php.

It is still debated whether discounting the changing baseline ocean temperature accurately reflects the status of ENSO and other teleconnections. As others have pointed out, historically warmer eras showed a more permanent +ENSO state, even though the baseline was theoretically higher. However, many recent papers, like Sabeerali et al. 2026 and L’Heureux et al. 2024 demonstrate that RONI more accurately predicts ENSO effects on global height and precipitation anomalies. I believe that (and this is pure conjecture) at least in the short term, when the climate change-induced effects on global SSTs remain within a couple of degrees of the pre-industrial state, RONI will remain more accurate. However, if we begin to approach departures of 5 degrees, maybe a reconsideration of the usefulness of ENSO would be in order.