El Niño Predictions

From NOAA and the National Weather Service

. Collectively, the coupled ocean-atmosphere system reflected the onset of El Niño conditions.

The North American Multi-Model Ensemble (NMME) average, including the NCEP CFSv2 [Fig. 6], forecasts El Niño to intensify into the Northern Hemisphere winter 2026-27. High confidence in El Niño [Fig. 7] is also linked to anomalously high oceanic heat content and expanding westerly wind anomalies across the equatorial Pacific Ocean. There is a 63% chance of a very strong El Niño during November-January [Fig. 8] that would rank among the largest El Niño events in the historical record going back to 1950. Even very strong El Niño events do not lead to the expected impact everywhere, but stronger events can more significantly tilt the odds in favor of expected outcomes (see CPC outlooks for probabilities of seasonal anomalies). In summary, El Niño conditions are present and expected to strengthen into the Northern Hemisphere winter 2026-27.

From Daniel Swain of Weather West:

“As we emerge from the so-called Spring Predictability Barrier, multi-model ensemble predictions have become even more aggressive and are now explicitly predicting an El Niño of very strong, and quite possibly record-breaking, magnitude by autumn or early winter. In fact, the just-released multi-model “superensemble” predictions for June are nothing short of remarkable, with the median forecast from every single international model ensemble depicting at least a “strong” event, and the majority indicating a top-tier, very strong-to-historic event. This is true using both the traditional and the newer “relative” El Niño index (or “RONI,” which is designed to more accurately reflect El Niño magnitude in a warming climate by removing ocean temperature differences arising from long-term trends). And the latest official forecast update from NOAA is consistent with these model predictions: It not only confirms that, as of June, El Niño is already underway, but also indicates nearly 90% odds of an event reaching at least “strong” intensity and over 60% odds of a “very strong” event.”