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. Nino3.4 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 continues and will strengthen through the end of the year, with a 97% chance it will persist through early spring 2027.

 

Discussion:

 

El Nino strengthened over the past month, with a large area of sea surface temperature anomalies in excess of +1.0C across the central and eastern equatorial Pacific (Fig. T18a). The monthly Nino-3.4 index value was +1.0C, with the westernmost (Nino-4) and easternmost (Nino-1+2) indices at +0.8C and +2.3C, respectively (https://www.cpc.ncep.noaa.gov/data/indices/rel_mthsst9120.txt). The equatorial subsurface temperature index (average from 180-100W) increased, as a recent downwelling Kelvin wave deepened the thermocline and raised temperatures in the eastern Pacific (Fig. T17). Low-level westerly wind anomalies and upper-level easterly wind anomalies were observed over the western and central equatorial Pacific (Figs. T20 & T21). Convection was enhanced over the central and east-central equatorial Pacific and was suppressed over Indonesia (Fig. T25). The traditional and equatorial Southern Oscillation indices were significantly negative (Figs. T1 & T2). Collectively, the coupled ocean-atmosphere system reflected a strengthening El Nino.

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 through 2026. Alongside model forecasts, a strong coupling of the atmospheric and oceanic circulation across the Pacific contributes to very high confidence that El Nino will continue through early 2027. There is an 81% chance of a very strong El Nino during October-December that would rank among the largest El Nino events in the historical record going back to 1950. Even the strongest El Nino events do not lead to the typical 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 continues and will strengthen through the end of the year, with a 97% chance it will last through early spring 2027.

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