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: La Niña Advisory
Outlook:
ENSO-neutral
conditions are expected to begin within the next couple of months, and persist
through the Northern Hemisphere spring and early summer.
Discussion:
Although a weak La Niña was still apparent during
January, below-average sea surface temperatures (SSTs) continued to weaken
further across the equatorial Pacific Ocean (Fig. T18). The monthly Niño index values were mostly
near -0.6C, with the exception of Niño-1+2 which was -0.2C (Table T2). Like the surface, negative subsurface
temperature anomalies continued to weaken, with above-average subsurface
temperatures expanding eastward at depth and near the surface of the eastern
Pacific Ocean (Fig. T17).
Low-level easterly wind anomalies continued, but were confined to the
western and central Pacific Ocean (Fig. T20).
Upper-level westerly wind anomalies were evident over the east-central
Pacific (Fig. T21). Suppressed convection persisted
over the western and central tropical Pacific, while enhanced convection was
observed over western Indonesia (Fig. T25). Overall, the coupled
ocean-atmosphere system continued to reflect La Niña.
The
most recent IRI plume predicts a transition from La Niña to ENSO-neutral in the
next couple of months (Figs. F1-F12). The forecaster consensus is largely in
agreement. ENSO-neutral is expected to
prevail during the spring and early summer. There are increasing chances of El
Niño at longer forecast horizons, though uncertainty remains high because of
the spring prediction barrier, which typically is associated with lower
forecast accuracy. In summary,
ENSO-neutral conditions are expected to begin within the next couple of months,
and persist through the Northern Hemisphere spring and early summer.
Weekly
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).