Forecast Forum
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. 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 Alert System Status: La Niña Advisory
Outlook:
La Niña is likely to transition to ENSO-neutral
conditions during March-May 2012.
Discussion:
A mature La Niña continued
during January 2012, as below-average sea surface temperatures (SST) persisted
across the equatorial Pacific Ocean (Fig. T18). The monthly
SST indices remained near –1.0°C in the Niño-3.4 and Niño-4 regions (Table
T2). However,
the negative SST anomalies weakened in the far eastern Pacific, indicated by
warming in the Niño-1+2 and Niño-3 regions.
The oceanic heat content (average temperature in the upper 300m of the
ocean) anomalies also weakened slightly, but continued to reflect an extensive
area of below-average subsurface temperatures east of the Date Line (Fig.
T17). Also,
anomalous low-level easterly and upper-level westerly winds persisted over the
central and west-central Pacific (Figs. T20,
T21). Convection remained suppressed in the western and
central Pacific, and enhanced over Indonesia (Fig. T25). Collectively, the oceanic and atmospheric
patterns reflect a weak-to-moderate strength La Niña.
A majority of models
predict La Niña to weaken through the rest of the Northern Hemisphere winter
2011-12, and then to dissipate during the spring 2012 (Figs. F1-F13). Also, there is evidence of a downwelling phase of an eastward-propagating oceanic Kelvin
wave, which may increase temperatures across the Pacific in the
next couple of months. The combination
of a weakening subsurface temperature anomaly, the historical seasonal
evolution, and forecaster preference for the average dynamical model prediction
favors a return to ENSO-neutral conditions during the Northern Hemisphere
spring, which are likely to continue into the summer. Therefore La Niña is likely to transition to
ENSO-neutral conditions during March-May 2012.
Weekly
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).