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.
conditions are likely to continue through March-May 2007.
Equatorial Pacific SST anomalies greater than +1ºC
were observed in most of the equatorial
Pacific between 170ºE and the South American coast
during December (Fig. T18).
The latest SST departures in
the Niño regions are around 1.0ºC,
except near 0.5ºC
for Niño 1+2 (Table
increase in SST anomalies during the last several months has been accompanied
by weaker-than-average low-level equatorial easterly winds across most of the
equatorial Pacific (Fig. T13) and negative
values of the Southern Oscillation Index (SOI)
(Table T1; Fig. T1).
these oceanic and atmospheric anomalies indicated the development
of El Niño 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
October-December 2006 is +1.1°C,
which indicates El Niño conditions. Most of the statistical and
coupled models indicate that SST anomalies are near their peak
and that decreasing anomalies are likely during early 2007 (Figs. F1,
F2, F3, F4a,
F4b, F5, F6,
F7, F8, F9,
F10, F11, F12
and F13), with the NCEP Climate Forecast System (CFS) indicating a rapid
weakening in the next month. Recent
observed trends in the upper ocean tend to support those forecasts.
This is a significant change from just a few weeks ago when a number
of the forecast tools were indicating the persistence or even increases in
SST anomalies during this period. The
large spread in the most recent set of forecasts indicates that there is
considerable uncertainty in this outlook.
A resurgence of MJO activity in late December 2006 has the potential
to trigger a more persistent pattern of cloudiness and precipitation over the
anomalously warm waters of the central equatorial Pacific during the next
several weeks. If that occurs, then the equatorial easterlies over the
central Pacific will likely weaken possibly leading to a continuation of El
Niño conditions beyond that which is currently indicated by the CFS. Please
refer to the ENSO Evolution, Status and Prediction Presentation available on
the CPC El Niño/ La Niña page for weekly updates on the latest conditions
in the tropical Pacific (see link below).
There is an increased probability of observing El Niño-related
effects over North America during January-March 2007, including
warmer-than-average temperatures over western and central
, and over the northern
, wetter-than-average conditions over portions of the
U.S. Gulf Coast and
, and drier-than-average conditions in the
in portions of the
. Global effects that can be expected during
January-March include drier-than-average conditions over portions of
Malaysia, Indonesia, northern and eastern Australia, some of the
U.S.-affiliated islands in the tropical North Pacific, northern South America
and southeastern Africa, and wetter-than-average conditions over central
South America (Uruguay, northeastern Argentina, southeastern Paraguay and
southern Brazil) and possibly along the coasts of Ecuador and northern Peru.
updates of SST, 850-hPa wind, OLR and features of the equatorial subsurface
thermal structure are available on the
Center homepage at: