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: Final La Niña Advisory
Outlook:
La Niña has ended and
ENSO-neutral conditions are expected to continue through the Northern Hemisphere
spring and early summer 2023.
Discussion:
During February 2023, below-average sea surface
temperatures (SSTs) weakened and currently persist only in the central Pacific
Ocean (Fig. T18). The latest monthly Niño-3.4 index
value was -0.4C (Table T2).
In contrast to the central Pacific, SSTs in parts of the eastern Pacific
Ocean were above average, with the latest Niño-1+2 index value at +0.7C. In the last month, area-averaged subsurface
temperatures became slightly above average, with positive temperature anomalies
spanning the Pacific, though remaining mostly at depth (Fig. T17). The atmospheric circulation anomalies across
the tropical Pacific are lagging the changes in the ocean. Low-level easterly wind anomalies continue
over the central Pacific Ocean (Fig. T20). Upper-level westerly wind
anomalies were evident over most of the Pacific (Fig. T21). Suppressed
convection persisted over the central tropical Pacific, while enhanced
convection was observed over Indonesia (Fig.
T25). Collectively, the coupled
ocean-atmosphere system was consistent with ENSO-neutral.
The
most recent IRI plume favors ENSO-neutral to continue through the spring, with
El Niño forming during summer 2023 and persisting through the fall (Figs. F1-F12). In contrast, the forecaster consensus favors
ENSO-neutral through summer 2023, with elevated chances of El Niño developing
afterwards. The smaller chances of El
Niño relative to the model predictions are primarily because ENSO forecasts
made during the spring are less accurate, and also the tropical Pacific
atmosphere is still fairly consistent with a cool/La Niña-like state. However, it is possible that strong warming
near South America may portend a more rapid evolution toward El Niño and will
be closely monitored. In summary, La
Niña has ended and ENSO-neutral conditions are expected to continue through the
Northern Hemisphere spring and early summer 2023.
Weekly
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).