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
ENSO Alert System Status: La Niña Advisory
La Niña conditions are predicted to continue (~65-75% chance) at least
through the Northern Hemisphere winter 2017-18.
October, weak La Niña conditions
emerged as reflected by below-average sea surface temperatures (SSTs) across
most of the central and eastern equatorial Pacific Ocean (Fig. T18). The monthly Niño-3.4
value was at -0.5°C (Table T2). Sub-surface
temperatures remained below average during October, reflecting the anomalously
shallow depth of the thermocline across the central and eastern Pacific (Fig. T17). Also,
convection was suppressed near the International Date Line and slightly
enhanced over parts of the Maritime Continent and the Philippines (Fig. T25). Over the
equatorial Pacific Ocean, low-level trade winds were mainly near average, but
the upper-level winds were strongly anomalously westerly (Fig. T20, Fig. T21) and the Southern Oscillation Index was
positive. Overall, the ocean and
atmosphere system reflects the onset of La Niña conditions.
For the remainder of the Northern
Hemisphere fall and winter 2017-18, a weak La Niña is favored in the model
averages of the IRI/CPC plume and also in the North American Multi-Model
Ensemble (NMME) (Figs. F1-F13). The consensus of forecasters is for the event to
continue through approximately February-April 2018. In summary, La Niña conditions are predicted to continue (~65-75% chance) at least
through the Northern Hemisphere winter.
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El
Niño/La Niña Current Conditions and Expert Discussions).