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: El Niño Advisory
Outlook:
There is an
approximately 95% chance that El Niño will continue through Northern Hemisphere
winter 2015-16, gradually weakening through spring 2016.
Discussion:
During August, sea surface temperature (SST) anomalies were near or
greater than +2.0°C across the eastern half of the tropical Pacific (Fig.
T18). SST anomalies increased in the Niño-3.4 and Niño
3-regions, were approximately unchanged in the Niño-4 region, and decreased in
the Niño-1+2 region (Table T2). Large positive subsurface temperature anomalies
persisted in the central and east-central equatorial Pacific during the month,
with the largest departures exceeding 6°C (Fig. T17). The atmosphere remained coupled to the anomalous
oceanic warmth, with significant low-level westerly wind anomalies and
upper-level easterly wind anomalies persisting from the western to east-central
tropical Pacific (Figs.T20, T21). Also, the traditional and equatorial Southern
Oscillation Index (SOI) were again negative (Table
T1 & Fig. T2), consistent with
enhanced convection over the central and eastern equatorial Pacific and
suppressed convection over Indonesia (Fig.T25). Collectively, these atmospheric and oceanic
anomalies reflect a strong El Niño.
All
models surveyed predict El Niño to continue into the Northern Hemisphere spring
2016, and all multi-model averages predict a peak in late fall/early winter
(3-month values of the Niño-3.4 index of +1.5°C or greater; Figs. F1-F13). The forecaster consensus
unanimously favors a strong El Niño, with peak 3-month SST departures in the
Nino 3.4 region near or exceeding +2.0°C. Overall, there is an approximately
95% chance that El Niño will continue through Northern Hemisphere winter
2015-16, gradually weakening through spring 2016.
Weekly updates of oceanic
and atmospheric conditions are available on the Climate Prediction Center
homepage (El
Niño/La Niña Current Conditions and Expert Discussions).