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
for the next several seasons, with ENSO-neutral favored during April-June 2024
(73% chance).
Discussion:
Above-average sea surface temperatures (SST) persisted
across the equatorial Pacific Ocean, with the largest anomalies observed in the
central and east-central Pacific (Fig. T18).
The monthly Niño index values were nearly unchanged: +1.4C in Niño-4, +2.0C
in Niño-3.4, and +2.1C in Niño-3. Only Niño-1+2
weakened to +1.4C (Table T2). Area-averaged positive subsurface temperature
anomalies decreased in December, reflecting the strengthening and eastward
expansion of below-average subsurface temperatures in the western Pacific (Fig. T17). Over the east-central Pacific Ocean, low-level
wind anomalies were westerly, while upper-level wind anomalies were easterly (Figs. T20
& T21).
Convection/rainfall remained enhanced at the Date Line and was
suppressed around Indonesia (Fig. T25).
The equatorial and station-based SOI were negative (Figs. T1 & T2).
Collectively, the coupled ocean-atmosphere system reflected a strong and
mature El Niño.
The
most recent IRI plume indicates El Niño will gradually weaken and then
transition to ENSO-neutral during spring 2024 (Figs. F1-F12). Some state-of
the-art dynamical climate models suggest a transition to ENSO-neutral as soon
as March-May 2024. The forecast team,
however, delays this timing and strongly favors a transition to ENSO-neutral in
April-June 2024. There are also
increasing odds of La Niña in the seasons following a shift to ENSO-neutral. It is typical for El Niño to peak in December/early
January, but despite weakening, its impacts on the United States could last through
April (see CPC seasonal outlooks for probabilities of temperature and
precipitation). In summary, El Niño is expected
to continue for the next several seasons, with ENSO-neutral favored during
April-June 2024 (73% 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).