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.
La Niña conditions are expected to
continue during the next 3-6 months.
The patterns of anomalous ocean temperatures, atmospheric circulation and
precipitation are consistent in indicating La Niña conditions in the
During January negative equatorial SST anomalies less than –0.5ºC were
observed at most locations between the date line and the South American
coast, while anomalies greater than +0.5ºC were restricted to the region
and 160ºE (Figs.
T9 and T18).
Negative SST departures increased in magnitude in the Niño 4 and Niño
3.4 regions (Table T2 and Fig.
T5), as the oceanic cold tongue strengthened in
the central equatorial Pacific.
above-average precipitation (negative OLR anomalies) was observed over
below-average precipitation (positive OLR anomalies) was observed over the
central equatorial Pacific (Figs. T8
and T25). Stronger-than-average low-level
(850-hPa) easterly winds (Figs. T7
and T13) persisted over the central equatorial
Pacific, and anomalous upper-level (200-hPa) cyclonic circulation centers
were observed in both hemispheres (Fig.
Collectively, the present
oceanic and atmospheric anomalies are consistent with La Niña conditions 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 November
2005 - January 2006 is -0.7°C,
which indicates La Niña conditions. Over the past several months most of the
statistical and coupled model forecasts have trended towards cooler
conditions in the tropical Pacific through mid-2006.
The spread of the most recent statistical and coupled model
forecasts (La Niña to ENSO-neutral) indicates some uncertainty in the
outlooks (Figs. F1,
F2, F3, F4a,
F4b, F5, F6,
F7, F8, F9,
F10, F11, F12
However, current conditions
(stronger-than-average easterly winds over the central equatorial Pacific)
and recent cooling trends in observed oceanic conditions support a
continuation of La Nina conditions in the tropical Pacific during the next
on current conditions in the tropical Pacific, the most recent SST
predictions, and on results from historical studies on the effects of cold
episodes, we expect wetter-than-normal (drier-than-normal) conditions to
(central equatorial Pacific) during the remainder of
the NH winter. That pattern of tropical precipitation favors a northward
shift in the position of the jet stream over the eastern North Pacific during
winter, which is usually accompanied by drier-than-normal conditions over
. The recent patterns of anomalous temperature and
precipitation for the
are similar to wintertime patterns observed during
previous La Niña episodes, except for temperature over the northern Plains
and in the
updates of SST, 850-hPa wind, OLR and features of the equatorial subsurface
thermal structure are available on the
Center homepage at: