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
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. 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
ENSO Alert System Status: Final La Niña Advisory
La Niña has
transitioned to ENSO-neutral conditions, which are expected to continue through
northern summer 2012.
La Niña dissipated during
April 2012, as below-average SSTs weakened across most of the equatorial
Pacific Ocean and above-average SSTs persisted in the east (Fig. T18). The Niño 4 and Niño 3.4 indices were warmer than
-0.5oC for the month, and the Niño 3 and Niño 1+2 indices remained
positive (Table T2). The oceanic heat
content (average temperature in the upper 300m of the ocean) anomalies also became
positive in April, as below-average sub-surface temperatures largely
disappeared and above-average sub-surface temperatures
expanded in both the central and eastern Pacific (Fig. T17). Consistent with the demise of La Niña, enhanced
trade winds and reduced convection over the central equatorial Pacific were
much weakened during April (Fig. T20), and the area of
enhanced convection that had previously dominated the western Pacific and
Indonesia became disorganized (Fig. T25). Collectively, these
oceanic and atmospheric patterns indicate a transition from La Niña to
The current and evolving
conditions, combined with model forecasts (Figs. F1-F13), suggest that La Niña is
unlikely to re-develop later this year. A majority of models predict
ENSO-neutral conditions to continue from April-June (AMJ) through the
June-August (JJA) season. However, at least half of the dynamical models
predict development of El Niño conditions by JJA. Still, from JJA onward there
is considerable forecast uncertainty as to whether ENSO-neutral or El Niño conditions
will prevail, due largely to the inability to predict whether the warmer SST
will result in the ocean-atmosphere coupling required for a sustained El Niño
event. The official forecast calls for ENSO-neutral conditions through JAS,
followed by approximately equal chances of Neutral or El Niño conditions for
the remainder of the year.
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).