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
Niña is favored to develop (~70% chance) during the Northern Hemisphere fall 2016
and slightly favored to persist (~55% chance) during winter 2016-17.
ENSO-Neutral conditions were observed during September, with negative sea
surface temperature (SST) anomalies expanding across the eastern equatorial
Pacific Ocean by early October (Fig. T18). For the September monthly average, the Niño-3.4
index was -0.6°C, though cooled even further by early October (Table T2). Subsurface
temperature anomalies also decreased toward the end of the month, reflecting
the strengthening of below-average temperatures at depth in the east-central
equatorial Pacific (Fig. T17). Atmospheric anomalies across the equatorial
Pacific edged toward La Niña during September, with a stronger tendency toward
La Niña late in the month. The traditional
Southern Oscillation index and the equatorial Southern Oscillation index were
positive (Table T1 & Fig. T2). The lower-level winds were near
average across most of the basin during the month, but enhanced easterlies were
becoming more persistent west of the International Date Line (Fig. T20).
Upper-level winds were anomalously westerly near and just east of the
International Date Line (Fig. T21). Convection was weakly suppressed over the
central tropical Pacific and was more enhanced over Indonesia compared to last
month (Fig. T25). Overall, the combined ocean and atmosphere
system reflects ENSO-Neutral during September, but is more clearly trending
toward La Niña conditions.
multi-model averages favor borderline Neutral-La Niña conditions (3-month
average Niño-3.4 index less than or equal to -0.5°C) persisting during the
Northern Hemisphere fall and continuing into the winter (Figs. F1-F13). Because of the recent cooling in the Niño-3.4
region and signs of renewed atmospheric coupling, the forecaster consensus now
favors the formation of a weak La Niña in the near term, becoming less confident
that La Niña will persist through the winter.
In summary, La Niña is favored
to develop (~70% chance) during the Northern Hemisphere fall 2016 and slightly
favored to persist (~55% chance) during winter 2016-17.
updates of oceanic and atmospheric conditions are available on the Climate
Prediction Center homepage (El Niño/La
Niña Current Conditions and Expert Discussions).