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. Niño 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: El Niño Advisory
Outlook: El Niño is expected to
continue through the Northern Hemisphere winter, with a transition to
ENSO-neutral favored during April-June 2024 (60% chance).
Discussion:
Sea surface temperatures (SST) were above average
across the equatorial Pacific Ocean (Fig.
T18), increasing in the central and
east-central Pacific during November. The
monthly Niño index values were +1.4C in Niño-4, +1.9C in Niño-3.4, +2.1C in
Niño-3, and +2.2C in Niño-1+2 (Table T2). Area-averaged positive subsurface temperature
anomalies increased significantly during November, reflecting the strengthening
of above-average subsurface temperatures in the central and eastern Pacific
associated with a downwelling oceanic Kelvin wave (Fig. T17). Low-level wind anomalies were westerly in the
central and eastern Pacific, while upper-level wind anomalies were easterly
across the Pacific (Figs. T20 & T21). Convection/rainfall remained enhanced at the
Date Line and was suppressed around Indonesia (Fig. T25). The equatorial Southern Oscillation Index
(SOI) and the station-based SOI were negative (Figs. T1 & T2).
Collectively, the coupled ocean-atmosphere system reflected a strong El
Niño.
The
most recent IRI plume favors El Niño to continue through the Northern
Hemisphere winter 2023-24 (Figs. F1-F12). Based on the latest forecasts, there is now a
54% chance of a “historically strong” El Niño during the November-January
season (>= 2.0C in Niño-3.4). An
event of this strength would potentially be in the top 5 of El Niño events
since 1950. While stronger El Niño events increase the likelihood of El
Niño-related climate anomalies, it does not imply expected impacts will emerge
in all locations or be of strong intensity (see CPC seasonal outlooks for
probabilities of temperature and precipitation). In summary, El Niño is expected to continue
through the Northern Hemisphere winter, with a transition to ENSO-neutral
favored during April-June 2024 (60% chance).
Weekly
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El Niño/La
Niña Current Conditions and Expert Discussions).