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.
October, equatorial SST anomalies greater than +0.5ºC were found between
Indonesia and 170ºW, while negative anomalies less than –0.5ºC were
observed at most locations between 130ºW and the South American coast (Figs.
T9 and T18).
The SST departures in the Niño 3, and Niño 1+2 regions were
negative, while weak positive departures were observed in the Niño 4 and Niño
3.4 regions (Table T2 and Fig. T5). During
the last three months surface and subsurface temperature anomalies decreased,
especially in the eastern equatorial Pacific(Figs. T9,
T15 and T17), and the
Southern Oscillation Index (SOI) increased (Fig. T2).
During the same period persistent stronger-than-average low-level equatorial
easterly winds were observed over the central Pacific (Figs. T7
and T13), 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 ENSO-neutral 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 August-October 2005 is 0.0°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
However, 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 during the next 6-9 months.
updates of SST, 850-hPa wind, OLR and features of the equatorial subsurface
thermal structure are available on the
Center homepage at: