CC
Written by Chris Corwin, IAMElNino.com · Drafted with AI research assistance, fact-checked against NOAA CPC source data, and reviewed before publication.
What "Very Strong" Actually Means — NOAA Probabilities
El Niño of any strength by autumn/winter~100%
At least "strong" intensity~88–90%
"Very strong" (Niño 3.4 > +2.0°C)60–63%
Current Niño 1+2 anomaly+2.1°C
Current Niño 3.4 anomaly+0.7°C
ECMWF December projection+3.0°C

Let's be precise about terminology first, because "Super El Niño" isn't an official NOAA category — it's shorthand the public and media use for what NOAA calls a "very strong" event: a peak seasonal Niño 3.4 relative anomaly above +2.0°C. By that strict definition, there have only been a handful of true Super El Niños in the satellite era — 1972–73, 1982–83, 1997–98, and 2015–16. If this one verifies, it would be the first since 2015–16.

Why Forecasters Are This Confident, This Early

Normally, June sits inside what climatologists call the Spring Predictability Barrier — a stretch where ENSO forecasts are historically unreliable because the ocean-atmosphere system is in transition. Models that are confident in June have, in past years, often been wrong by August.

What's different this time is the subsurface signal. A large, well-organized downwelling Kelvin wave — essentially a slow-moving pulse of warm water below the surface — has been propagating east across the equatorial Pacific for weeks, with subsurface anomalies reported as high as +8°C at 50–250m depth. That's running warmer than the equivalent stage of the 1997–98 event, which is the closest thing the modern record has to today's setup.

NASA's Sentinel-6 Michael Freilich satellite, which measures sea surface height (a proxy for subsurface heat — warmer water expands and the surface literally rises), shows a pattern in the western Pacific on June 8 that JPL scientists described as visually similar to 1997 at the same point in the year. The eastern Pacific, however, is lagging behind 1997's pace — fewer Kelvin waves have arrived there so far. Whether this event "catches up" to 1997's trajectory is still an open question.

"For now, it looks like it's going to be a big one — more so than I would have said last week — but we still need more observations to know what's going to happen."

— Severine Fournier, NASA JPL, Sentinel-6 deputy project scientist

How the Models Compare

What's notable isn't any single model — it's that NOAA's CFSv2, the European ECMWF, and Australia's BOM are now converging on the same outcome, which historically has been a stronger confidence signal than any one center's forecast alone.

SourceForecastConfidence Trend
NOAA CPC63% chance "very strong" by NDJ 2026-27Watch → Advisory (June 11)
ECMWF~100% probability of "super" threshold22% (Mar) → 80% (Apr) → ~100% (May)
CSU Hurricane TeamHurricane forecast cut to 11 named stormsDown from 13, cited directly to El Niño shear
IRI/Columbia98% probability El Niño persists through early 2027Up from 82% two weeks prior

That rate of escalation — particularly ECMWF's jump from 22% to effectively 100% probability in under two months — is itself unusual. Forecasters have explicitly noted it's a steeper buildup than the lead-up to either 1997–98 or 2015–16.

Why This Matters Beyond the Headlines

A strong El Niño isn't just an ocean curiosity — it reorganizes global weather for 6–12 months and reliably nudges global average temperature upward on top of the existing human-caused warming trend, since the two effects are additive rather than competing. Scientists have described El Niño as acting like a temporary "mini global warming" event: it releases heat that's been stored in the deep ocean for years and dumps it into the atmosphere, where it raises surface temperatures for the duration of the event before the ocean re-absorbs heat during the following La Niña or neutral phase.

The practical, near-term effects already visible: the 2026 Atlantic hurricane season has opened unusually quiet, with El Niño's increased upper-level wind shear suppressing storm formation before the season even got going — CSU's most recent outlook reflects that directly. On the flip side, the eastern and central Pacific hurricane basin tends to get more active under El Niño, which is consistent with what's been observed so far this year.

The Honest Uncertainty

None of this is locked in. NOAA's own language is careful to note "substantial uncertainty in the peak strength," and the gap between the eastern Pacific's slower warming and the western Pacific's 1997-like signal is a real open question, not a rounding error. A 63% probability of "very strong" also means there's a real chance — roughly 1 in 3 — that this event peaks at merely "strong," which would still be a significant event, just not a historic one.

What we can say with more confidence: this site's own RONI tracker and SST spaghetti chart are already showing this year's trajectory running well above both the 1997 and 2015 analog lines at the same point in the calendar — which is exactly the kind of real-time confirmation that's been feeding the "Super El Niño" headlines. We'll keep updating as the weekly CPC data comes in.