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
The predictions from the National Centers for
Environmental Prediction (NCEP) Coupled Forecast System Model (CFS03) 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 using linear inverse modeling (Penland and Magorian 1993: J.
Climate, 6, 1067‑1076) are shown in Figs. F9 and F10. Predictions from the Scripps / Max Planck
Institute (MPI) hybrid coupled model (Barnett et al. 1993: J. Climate, 6,
1545‑1566) are shown in Fig. F11.
Predictions from the ENSO‑CLIPER statistical model (Knaff and Landsea 1997, Wea.
Forecasting, 12, 633‑652) are shown in Fig. F12. Niño 3.4 predictions are summarized in Fig.
F13, 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
ENSO Alert System Status: La Niña Advisory
La Niña is
expected to continue through the Northern Hemisphere winter 2011-12.
During November 2011,
below-average sea surface temperatures (SST) associated with La Niña conditions
continued across the eastern and central equatorial Pacific Ocean (Fig. T18). The monthly SST indices in the Niño-3.4 and
Niño-3 regions were near –1.0°C (Table T2), indicative of weak to
moderate La Niña. The oceanic heat
content (average temperature in the upper 300m of the ocean) weakened slightly,
but still indicates a large area of below-average temperatures at depth in the
eastern Pacific (Fig. T17). Also reflecting La Niña, the atmospheric
circulation over the global tropics featured anomalous low-level easterly and
upper-level westerly winds in the central and west-central Pacific (Figs.
T20, T21). Averaged over the
month, convection was suppressed near and just west of the Date Line and
enhanced over northern Australia and parts of Indonesia (Fig. T25). Collectively, these oceanic and atmospheric
patterns are consistent with the continuation of La Niña conditions.
A majority of the models
predict a weak or moderate strength La Niña to continue through the Northern
Hemisphere winter (Figs. F1-F13) and then gradually weaken after peaking during the
December – January period. The models are
roughly split between those that predict La Niña to remain weak (3-month
average in the Nino-3.4 region between -0.5 and -0.9°C) and those that predict
a stronger episode. Over the last half-century, La Niña events that were
preceded by ENSO-neutral conditions during the Northern Hemisphere summer
(May-August) were less likely to attain strong amplitude (stronger than –1.5°C)
the following winter. This observation,
in combination with the model forecasts, favors a weak-to-moderate strength La
Niña during the Northern Hemisphere winter, likely weakening with the onset of
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).