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
ocean/atmosphere model (Ji et al. 1998, Mon. Wea. Rev, 126, 1022-1034) are
presented in Figs. F3 and F4a, F4b. Predictions from the Markov model (Xue,
Y. et al. 2000: ENSO prediction with Markov model: The impact of sea level. J. Climate,
13, 849-871) are shown in Figs. F5 and F6.
Predictions from the latest version of the LDEO model (Chen,
D. 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, J. A. and C. W. Landsea 1997, Wea. Forecasting, 12, 633-652) are
shown in Fig. F12. Niño
3.4 predictions are summarized in F13,
which is 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.
Based on current atmospheric and oceanic conditions
and recent observed trends, it is likely that ENSO-neutral conditions
will continue in the equatorial Pacific for the next 3-6 months.
Sea surface temperature (SST) anomalies (departures from average)
decreased in most of the equatorial Pacific during February (Fig.
T9, Table T2). Near-average or slightly
cooler-than-average SSTs were observed everywhere east of 180°W,
with positive anomalies greater than +0.5°C
(~1°F) being restricted to the region
between Indonesia and 180°W (Fig.
early December 2003, SST anomalies have decreased in all of the Niño
regions (Table T2).
The monthly 850-hPa zonal wind indices, OLR index, 200-hPa zonal wind
index, SOI and EQSOI have exhibited considerable intraseasonal
variability since November in association with tropical Madden-Julian
Oscillation (MJO) activity (Table T1, Fig.
T2). In spite of that variability, certain average atmospheric
patterns have become apparent since November. These include: 1)
stronger-than-average easterly winds between 160°E
and 150°W (Figs. T7,
T20), and 2) weaker-than-average convection
(drier-than-average conditions) over the central equatorial Pacific (Figs.
T11, T25). These
conditions are consistent with the observed decrease in SST anomalies in
the central equatorial Pacific (Table T2,
A majority of the statistical and coupled model forecasts indicate
near-average conditions in the equatorial Pacific (Niño
3.4 SST anomalies between -0.5°C
and +0.5°C) through May 2004 (Figs. F1, F2,
F3, F4a, F4b, F5,
F6, F7, F8,
F9, F10, F11,
Thereafter, the forecasts show increasing spread and greater
uncertainty. The three-month (December-February) average SST anomaly in
the Niño 3.4 region (+0.4°C)
is within the ENSO-neutral range. Given the recent trends and observed
oceanic and atmospheric conditions discussed above, it is likely that
ENSO-neutral conditions will continue in the equatorial Pacific for the
next 3-6 months.
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: