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 predictions from the National Centers for
Environmental Prediction (NCEP) Coupled Forecast System Model (CFS03) are
presented in Figs. F3 and F4. 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
Predictions using linear inverse modeling (Penland and Magorian 1993:
J. Climate, 6, 1067-1076) are shown in Figs. F9 and
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.
Niņo 3.4 predictions are summarized in Fig. F13, provided by the
Forecasting and Prediction Research Group of the IRI.
CPC and the contributors to the Forecast Forum caution potential users of
this predictive information that they can expect only modest skill.
Niņa conditions will develop further during the next 3 months.
August 2007, negative sea surface temperature (SST) anomalies in the eastern
equatorial Pacific expanded westward, and now extend from the coast of South
America to the date line (180ēW) (Fig.
Consistent with this additional cooling, three of the Niņo
indices remained cooler than −0.5
ēC throughout August, with only Niņo 4 remaining average (August monthly
values: Niņo 1+2 (−1.6ēC), Niņo 3 (−1.1ēC), Niņo 3.4
(−0.5ēC), Niņo 4 (+0.1ēC)) (Table
upper-ocean heat content (average temperatures in the upper 300 m of the ocean)
in the central and east-central equatorial Pacific also remained below
average, with temperatures at thermocline depth ranging from 1°C to 3°C below
average (Fig. T17).
While not as pronounced as in previous months, the low-level easterly
winds remained stronger than average in the west-central equatorial Pacific (Fig. T20),
convection was suppressed throughout the central and eastern equatorial Pacific,
and an area of slightly enhanced convection again covered parts of
and the far western Pacific (Fig. T25). Collectively, the oceanic
and atmospheric conditions reflect La Niņa
The recent SST
forecasts for the Niņo 3.4 region
range from ENSO-neutral to La Niņa (Figs.
Nearly all of the dynamical ENSO models forecast the continuing
development of La Niņa
during the next couple of months, and several of the statistical models also
indicate the continuation of La Niņa conditions through the end of the year.
Therefore, current atmospheric conditions (stronger than average
easterlies over the west-central Pacific) and observed oceanic trends indicate
that La Niņa conditions will develop further and possibly strengthen during the
next 3 months.
updates of oceanic and atmospheric conditions are available on the Climate
Niņo/La Niņa Current Conditions and Expert Discussions).