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: La Nina
conditions are expected to persist in the near-term, with a transition to ENSO-neutral
likely during March-May 2025 (66% chance).
Discussion:
La Nina conditions continued this past month, as
indicated by the below-average sea surface temperatures (SSTs) across the
central and east-central equatorial Pacific Ocean (Fig. T18). The latest monthly
indices were -0.7C in Nino-3.4 and -0.6C in Nino-4, with values closer to zero
in Nino-1+2 and Nino-3 (Table T2).
Below-average subsurface temperatures persisted, with below-average
temperatures dominating the central and eastern equatorial Pacific Ocean (Fig. T17).
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
over the Date Line and western Pacific and was enhanced over Indonesia (Fig. T25).
The traditional and equatorial Southern Oscillation indices were positive (Figs.
T1 & T2).
Collectively, the coupled ocean-atmosphere system indicated La Nina conditions.
The
IRI multi-model average predicts weak La Nina conditions to continue through
February-April 2025 and then transition to ENSO-neutral (Figs. F1-F12). The IRI dynamical model average and several of the
models from the North American Multi-Model Ensemble (NMME) predict an earlier
transition to ENSO-neutral in January-March 2025. The forecast team favors a
weak La Nina through February-April, but there is also a 41% chance of ENSO-neutral
emerging in this season. A weak La Nina is less likely to result in
conventional winter/spring impacts, though predictable signals can still
influence the forecast guidance (e.g., CPC's seasonal outlooks). In summary, La
Nina conditions are expected to persist in the near-term, with a transition to
ENSO-neutral likely during March-May 2025 (66% chance).
Weekly updates of oceanic and atmospheric conditions
are available on the Climate Prediction Center homepage (El Nino/La
Nina Current Conditions and Expert Discussions).