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.

 

ENSO Alert System Status: Final La Nina Advisory

 

Outlook: ENSO-neutral is favored during the Northern Hemisphere summer, with a greater than 50% chance through August-October 2025.

 

Discussion:

 

In March 2025, ENSO-neutral conditions returned, with below-average sea surface temperatures (SSTs) weakening in the central and east-central equatorial Pacific Ocean (Fig. T18). The westernmost Nino index values were near-to-below average, while positive index values persisted in the easternmost Nino-3 and Nino-1+2 regions (Table T2). Below-average subsurface temperatures weakened, but negative anomalies continued in the central equatorial Pacific, extending to 250m depth (Fig. T17). A shallow layer of above-average subsurface temperatures continued in the far eastern equatorial Pacific. Low-level wind anomalies remained easterly over the western and central Pacific, while upper-level wind anomalies were westerly over the central Pacific (Figs. T20 & T21). Convection was suppressed around the Date Line and was enhanced near Indonesia (Fig. T25). The traditional and equatorial Southern Oscillation indices were positive. Collectively, the coupled ocean-atmosphere system reflected ENSO-neutral conditions.

The IRI and North American multi-model ensemble indicate ENSO-neutral will continue through the summer (Figs. F1-F12). The forecast team also favors ENSO-neutral, with chances well over 50% through summer 2025. Because of reduced forecast accuracy in the spring, the uncertainty increases at longer time horizons, with a 43% chance of ENSO-neutral and a 38% chance of La Nina during November 2025 - January 2026 (chances of El Nino are under 20%). In summary, ENSO-neutral is favored during the Northern Hemisphere summer, with a greater than 50% chance through August-October 2025.

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