It is official now. NOAA has issued an El Niño Advisory: the warm phase of the Pacific has arrived and is expected to strengthen into the northern-hemisphere winter. The headline number has climbed fast — the key central-Pacific temperature anomaly reached roughly +1.7°C in mid-June, up from under +1°C a month earlier — and the models are increasingly of one mind about where it goes next.
That direction is upward, and possibly into rare territory. The international model ensemble now puts the probability of El Niño through autumn at effectively 100 percent, with most models clearing the +2.0°C mark — the threshold NOAA calls "very strong" — at the forecast peak around September to November. Roughly half the dynamical models reach that very-strong tier; NOAA itself puts the odds of crossing it at about 63 percent. Read through the newer, climate-adjusted index that several scientists now prefer, the signal is starker still: nearly every model peaks at "strong" or above, most reach the colloquial "super" category, and a majority project an event exceeding the historic 1982–83 benchmark. A few of the most aggressive runs push the eastern Pacific past +3°C by late autumn. Super events arrive about once a decade or less — the last three were 2015–16, 1997–98 and 1982–83.
A very strong El Niño rearranges weather across both hemispheres in roughly known ways. It tends to suppress Atlantic hurricane formation while energising the central and eastern Pacific; to wet the southern United States and raise high-tide flooding risk on the West Coast; to dry out parts of the western Pacific, Southeast Asia, Australia and the northern Horn of Africa; and to push an already-warm planet warmer still, with the largest global temperature effect usually landing the year after onset. For the ocean specifically it shuffles marine life — warm-water species pressing poleward, cold-water species going deeper — and tends to trigger harmful algal blooms along the eastern Pacific margin. These are the fingerprints of past strong events, not guarantees about this one.
That distinction is the point, and it is where the honest forecast lives. Peak strength and timing are still uncertain, and no one can say in June whether any particular place — a flooded California winter, a failed East African rains — will see the canonical impact. The most that can be said is that a very strong event is now the single most likely outcome, a heavily loaded die rather than a settled result. It is worth saying plainly because the louder the forecast gets, the more it attracts breathless certainty it cannot support; one of the scientists tracking it most closely has spent as much effort warning against exaggeration as describing the event itself.
The Pacific has exhaled like this before, and the world carries a rough memory of what tends to follow — flood and drought trading places across the map. This one is shaping up larger than most. The value of the forecast is not prophecy. It is time: the months of warning in which the decisions that matter — water, harvests, hurricane and flood preparation — can still be made.
Sources
The declared event. NOAA issued an El Niño Advisory; the Climate Prediction Center reports El Niño conditions present and strengthening into winter 2026–27; the mid-June weekly Niño-3.4 anomaly reached ~+1.7°C (NOAA; NOAA/CPC ENSO Diagnostic Discussion; IRI June 2026 Quick Look).
The forecast strength. The June IRI/CCSR ensemble assigns ~100% El Niño probability through autumn, with most models exceeding +2.0°C and ~13 of 24 reaching "very strong" at the SON peak; NOAA puts the odds of exceeding +2.0°C at ~63%; on the climate-adjusted RONI index, ~100% of model medians peak at "strong" or above and most reach "super," with several exceeding the 1982–83 record (IRI; NOAA; Weather West / Daniel Swain; ECMWF and NCEP CFSv2 via Severe Weather Europe).
Impacts and calibration. Typical very-strong-El-Niño effects include a suppressed Atlantic hurricane season, wetter southern US, drought risk in the western Pacific and northern Horn of Africa, global temperature amplification, and marine ecosystem shifts; forecasters stress that peak intensity, timing and specific regional impacts remain uncertain this far out (NOAA; WMO "Prepare for El Niño"; Weather West).
Further Reading
NOAA Climate Prediction Center and WMO — the official, deliberately measured outlooks and their probability framing.
Weather West (Daniel Swain) — the strongest "super" signal in the data, paired with an explicit warning against over-reading it; the model for calibrated alarm.
Severe Weather Europe — the most aggressive model runs (the record-rivaling scenario), useful as the high-end case to weigh against the cautious ones.