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: El Niño Watch
ENSO-neutral/ weak El Niño conditions are expected to continue into Northern
Hemisphere winter 2012-13, possibly strengthening during the next few months.
During September 2012, the
trend towards El Niño slowed in several key oceanic and atmospheric
indicators. However, the Pacific basin
reflects borderline ENSO-neutral/ weak El Niño conditions. Equatorial sea surface temperatures (SST)
remained elevated across the Pacific Ocean (Fig. T18), although anomalies decreased during the month in
the Niño-3 and Niño-3.4 regions (Table T2). The
oceanic heat content (average temperature in the upper 300m of the ocean)
anomalies also weakened, but continued to show large regions of above-average
temperatures at depth across the equatorial Pacific (Fig. T17).
Interestingly, low-level westerly wind anomalies were evident over the
equatorial western Pacific Ocean (Fig. T20), which may portend possible strengthening of the
subsurface anomalies in the coming months.
Despite these winds, the atmosphere was still largely ENSO-neutral, as
reflected by the Southern Oscillation index (Table T1) and near-average upper-level and lower-level winds
across much of the Pacific (Figs. T20 and T21). Tropical
convection increased near the Date Line, which is consistent with weak El Niño
conditions, but also remained elevated over eastern Indonesia, which is further
westward than expected (Fig. T25). Thus, the atmosphere and ocean indicate
borderline ENSO-neutral/ weak El Niño conditions.
Compared to the past few
months, the chance is reduced for El Niño to develop during Northern Hemisphere
fall/winter 2012-13. Due to the recent slowdown in the development of El Nino,
it is not clear whether a fully coupled El Niño will emerge. The majority of
models indicate that borderline ENSO-neutral/ weak El Niño conditions will
continue, and about half suggest that El Niño could develop, but remain weak (Figs.
F1-F13). The official forecast therefore
favors the continuation of borderline ENSO-neutral/ weak El Niño conditions
into Northern Hemisphere winter 2012-13, with the possibility of strengthening
during the next few months.
Weekly updates of oceanic
and atmospheric conditions are available on the Climate Prediction Center
Niño/La Niña Current Conditions and Expert Discussions).