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 conditions are expected to prevail during the
next 3-6 months.
The patterns of anomalous ocean temperatures during May 2006 were consistent
with ENSO-neutral conditions in the tropical Pacific. SSTs were near average at most
locations between the date line (180°) and 90ºW
(Fig. T18), which is reflected in the
near zero departures observed in the Niño regions (Table T2 and Fig.
the month above-average precipitation (negative OLR anomalies) was observed
over portions of
below-average precipitation (positive OLR anomalies) was observed over most
of the equatorial Pacific (Fig. T25).
Low-level (850-hPa) and upper-level (200-hPa) winds over the tropical Pacific
were near average during the month (Figs.
T20 and T21, respectively).
The equatorial subsurface temperature
anomaly pattern featured negative anomalies in the eastern Pacific and
positive anomalies in the western and central Pacific during May 2006 (Fig. T17). Since February the area of positive anomalies at
depth has expanded to the east (Fig. T15), and the basin-wide upper ocean heat content
increased. Collectively, these atmospheric and oceanic features indicate ENSO-neutral
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 March -
May 2006 is -0.2°C, which
indicates ENSO neutral conditions. Most
of the statistical and coupled model forecasts indicate ENSO-neutral
conditions in the tropical Pacific through the end
of 2006 (Figs. F1,
F2, F3, F4a,
F4b, F5, F6,
F7, F8, F9,
F10, F11, F12
However, the spread of
these forecasts (weak La Niña to weak El Niño)
indicates considerable uncertainty in the outlook for the last half of the
updates of SST, 850-hPa wind, OLR and features of the equatorial subsurface
thermal structure are available on the
Center homepage at: