Forecast Forum

The canonical correlation analysis (CCA) forecast of SST in the central Pacific (Barnett et al. 1988, Science, 241, 192‑196; Barnston and Ropelewski 1992, J. Climate, 5, 1316‑1345), is shown in Figs. F1 and F2. This forecast is produced routinely by the Prediction Branch of the Climate Prediction Center. The predictions from the National Centers for Environmental Prediction (NCEP) Coupled Forecast System Model (CFSv2) are presented in Figs. F3 and F4a, F4b. Predictions from the Markov model (Xue, et al. 2000: J. Climate, 13, 849‑871) are shown in Figs. F5 and F6. Predictions from the latest version of the LDEO model (Chen et al. 2000: Geophys. Res. Let., 27, 2585‑2587) are shown in Figs. F7 and F8. Predictions from the ENSO‑CLIPER statistical model (Knaff and Landsea 1997, Wea. Forecasting, 12, 633‑652) are shown in Fig. F9. Nino 3.4 predictions are summarized in Fig. F10, provided by the Forecasting and Prediction Research Group of the IRI.

The CPC and the contributors to the Forecast Forum caution potential users of this predictive information that they can expect only modest skill.

 

Notice: As of 1 February, 2026, sea surface temperature anomalies are now based on relative sea surface temperature anomalies for ENSO monitoring and forecasting. See NWS Public Information Statement 26-05.

 

ENSO Alert System Status: El Nino Advisory

 

Outlook: El Nino conditions are present and expected to strengthen into the Northern Hemisphere winter 2026-27.

 

Discussion:

 

El Nino conditions developed over the past month, as shown by above-average sea surface temperatures (SSTs) across the central to eastern equatorial Pacific Ocean (Fig. T18a). The monthly Nino-3.4 index value was +0.5C, with the westernmost (Nino-4) and easternmost (Nino-1+2) indices at +0.6C and +1.4C, respectively (https://www.cpc.ncep.noaa.gov/data/indices/rel_mthsst9120.txt). The equatorial subsurface temperature index (average from 180-100W) decreased in the past month, but significantly above-average subsurface temperatures remained in the central and eastern equatorial Pacific (Fig. T17). Low-level westerly wind anomalies and upper-level easterly wind anomalies were evident over the central equatorial Pacific (Figs. T20 & T21). Convection was slightly above average over the central and east-central equatorial Pacific and was near or below average over Indonesia (Fig. T25). The traditional and equatorial Southern Oscillation indices were negative (Figs. T1 & T2). Collectively, the coupled ocean-atmosphere system reflected the onset of El Nino conditions.

The North American Multi-Model Ensemble (NMME) average, including the NCEP CFSv2 (https://www.cpc.ncep.noaa.gov/products/CFSv2/imagesInd3/rnino34Sea.gif), forecasts El Nino to intensify into the Northern Hemisphere winter 2026-27. High confidence in El Nino 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 Nino during November-January that would rank among the largest El Nino events in the historical record going back to 1950. Even very strong El Nino 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 Nino conditions are present and expected to strengthen into the Northern Hemisphere winter 2026-27.

Weekly updates of oceanic and atmospheric conditions are available on the Climate Prediction Center homepage (El Nino/La Nina Current Conditions and Expert Discussions).