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 a
greater than 90% chance that El Niño will continue through Northern Hemisphere
winter 2015-16, and around an 80% chance it will last into early spring 2016.
Discussion:
During
June, sea surface temperature (SST) anomalies exceeded +1.0°C across the
central and eastern equatorial Pacific Ocean (Fig. T18). Compared
to last month, the largest SST anomaly increases occurred in the Niño-3 and
Niño-3.4 regions, while the Niño-4 and Niño-1+2 indices were approximately the
same (Table T2). Positive subsurface temperature anomalies weakened
due to the eastward shift of an upwelling oceanic Kelvin wave, which reduced
above-average temperatures at depth in the central and east-central equatorial Pacific
(Fig. T17). In
many respects, the atmospheric anomalies remained firmly coupled to the oceanic
warming. Significant westerly winds were
apparent in the western equatorial Pacific and anomalous upper-level easterly
winds continued (Figs. T20, T21). The traditional and equatorial Southern
Oscillation Index (SOI) were both negative (Table
T1 & Fig. T2), which are consistent with enhanced convection
over the central and eastern equatorial Pacific and suppressed convection over
Indonesia (Fig. T25). Collectively, these atmospheric and oceanic
features reflect an ongoing and strengthening El Niño.
Nearly
all models predict El Niño to continue into the Northern Hemisphere winter
2015-16, with many multi-model averages predicting a strong event at its peak
strength (3-month values of the Niño-3.4 index of +1.5°C or greater; Figs.
F1-F13). At this time, the
forecaster consensus is in favor of a significant El Niño in excess of +1.5°C
in the Niño-3.4 region. Overall, there is a greater than 90% chance that El Niño will
continue through Northern Hemisphere winter 2015-16, and around an 80% chance
it will last into early 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).