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
. The predictions from the National Centers for
Environmental Prediction (NCEP) Coupled Forecast System Model (CFS03) are
presented in Figs. F3 and F4a,
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
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 skill.
ENSO-neutral or weak La
Niña conditions are likely during the next 6-9 months.
During November, equatorial SST anomalies greater than +0.5ºC were
restricted to the region between Indonesia and 170ºE, while negative
anomalies less than –0.5ºC were observed at most locations between 145ºW
and the South American coast (Figs. T9
and T18). The SST departures
in the Niño 3, Niño 3.4 and Niño 1+2 regions were negative, while weak
positive departures were observed in the Niño 4 region (Table
T2 and Fig. T5).
During the last several months surface and
subsurface temperature anomalies have decreased in the region between 180°W
and the South American coast (Figs. T9, T15 and
During the same period persistent
stronger-than-average low-level equatorial easterly winds were observed over
the central Pacific (Figs. T7 and
while near-average patterns of convection (Figs.
T8 and T25) and sea level pressure (Figs.
T10 and T19) occurred over most of the tropical Pacific.
Collectively, the present oceanic and atmospheric anomalies are
consistent with a trend towards La Niña conditions in the tropical Pacific.
The value of the Oceanic Niño Index (ONI; 3-month running mean average of SST anomalies in
the Niño 3.4 region – computed using the Extended Reconstructed SST
version-2 data set) for September-November 2005 is -0.2°C, which indicates ENSO
neutral conditions. The spread of the most recent statistical and
coupled model forecasts (weak La Niña to weak El Niño)
indicates some uncertainty in the outlooks (Figs. F1,
F2, F3, F4a,
F4b, F5, F6,
F7, F8, F9,
F10, F11, F12
current conditions (stronger-than-average easterly winds over the central
equatorial Pacific) and recent observed trends (decreasing SST anomalies
throughout the central and eastern equatorial Pacific) do not support the
development of El Niño. Rather, they support either a continuation of ENSO-neutral
conditions or the development of weak La Niña conditions.
updates of SST, 850-hPa wind, OLR and features of the equatorial subsurface
thermal structure are available on the
Center homepage at: