|
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
Prediction
Center
. 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.
Ni�o 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.
Outlook
El Ni�o
conditions are likely to continue into early 2007.
Discussion
Equatorial Pacific SST anomalies greater than +1�C were observed in most of
the equatorial Pacific between 170�E and the South American coast during
November (Fig. T18).
The latest SST departures in the Ni�o regions are all near +1.0�C (Table
T2, Fig. T5).
The 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).
Collectively, these oceanic and atmospheric anomalies are consistent with the
early stages of El Ni�o in the tropical Pacific.
The value of the Oceanic Ni�o Index (ONI; 3-month running mean average of SST anomalies in
the Ni�o 3.4 region � computed
using the Extended Reconstructed SST version-2 data set) for
September-November 2006 is +0.9�C,
which indicates El Ni�o conditions. Most
of the statistical and coupled model forecasts (Figs. F1,
F2, F3, F4a,
F4b, F5, F6,
F7, F8, F9,
F10, F11, F12
and F13),
including the NCEP Climate Forecast System (CFS),
indicate that El
Ni�o conditions will peak during the
NH winter (December 2006-February 2007), followed by weakening during the NH
spring (March-May 2007).
Typical El Ni�o effects are likely over
North America
during January-March 2007, including
warmer-than-average temperatures over western and central
Canada
, and over the northwestern and northern
United States
, wetter-than-average conditions over portions
of the U.S. Gulf Coast and
Florida
, and drier-than-average conditions over the
Ohio
Valley
and over portions of the
Pacific Northwest
. Global
effects that can be expected during December-March include drier-than-average
conditions over most 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 equatorial East Africa, central South America (Uruguay, northeastern
Argentina, and southern Brazil) and along the coasts of Ecuador and northern
Peru.
Weekly
updates of SST, 850-hPa wind, OLR and features of the equatorial subsurface
thermal structure are available on the
Climate
Prediction
Center homepage at:
http://www.cpc.ncep.noaa.gov/
|
www.nws.noaa.gov
