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: La Nina Advisory

 

Outlook: ENSO-neutral is favored to develop in the next month and persist through the Northern Hemisphere summer (62% chance in June-August 2025).

 

Discussion:

 

During February 2025, below-average sea surface temperatures (SSTs) weakened in the central and east-central equatorial Pacific Ocean (Fig. T18). Most of the Nino indices reflected this decline, with near-to-below average values lingering in the Nino-3.4 and Nino-4 regions (Table T2). Coastal warming was evident near South America, with the latest Nino-1+2 value at 0.7C. This warming, however, was shallow (in the upper 50m) and was associated with low-level westerly wind anomalies over the eastern Pacific. Below-average subsurface temperatures also weakened, but negative anomalies persisted at depth in the eastern Pacific and extended down to 200m in the central Pacific (Fig. T17). Tropical Pacific atmospheric anomalies continued to indicate La Nina conditions. Low-level wind anomalies remained easterly over the western and central Pacific, while upper-level wind anomalies were westerly over the east-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 (Figs. T1 & T2). Collectively, the coupled ocean-atmosphere system reflected weakening La Nina conditions and a trend toward ENSO-neutral.

The IRI and North American multi-model ensemble predicts a transition to ENSO-neutral in the coming season (Figs. F1-F12). The forecast team concurs and predicts ENSO-neutral, with chances greater than 50% through July-September 2025. As is typical for forecasts made in the spring, there is large forecast uncertainty at longer time horizons, with no outcome exceeding a 50% chance (chances of El Nino are the lowest). In summary, ENSO-neutral is favored to develop in the next month and persist through the Northern Hemisphere summer (62% chance in June-August 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).