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: El Niño Advisory
There is a greater than 90% chance that El Niño will
continue through Northern Hemisphere fall 2015, and around an 85% chance it
will last through the 2015-16 winter.
May, sea surface temperatures (SST) anomalies increased across the central and
eastern equatorial Pacific Ocean (Fig. T18). All of the Niño indices were in excess of
+1.0°C, with the largest anomalies in the eastern Pacific, indicated by recent
weekly values of +1.4°C in Niño-3 and +1.9°C in Niño-1+2 (Table T2). After a
slight decline in April, positive subsurface temperature anomalies strengthened
during May in association with the progress of a downwelling
oceanic Kelvin wave (Fig. T17). In addition, anomalous low-level westerly
winds remained over most of the equatorial Pacific, and were accompanied by
anomalous upper-level easterly winds (Figs.T20, T21). The traditional and
equatorial Southern Oscillation Index (SOI) were both
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 features reflect an ongoing and strengthening El
Nearly all models predict
El Niño to continue throughout 2015, with many predicting SST anomalies to
increase into the late fall 2015 (Figs. F1-F13). For the fall and early winter, the consensus
of forecasters slightly favors a strong event (3-month values of the Niño-3.4
index +1.5°C or greater), relative to a weaker event. However, this prediction
may vary in the months ahead as strength forecasts are the most challenging
aspect of ENSO prediction. A moderate,
weak, or even no El Niño remains possible, though at increasingly lesser
odds. There is a greater than 90% chance
that El Niño will continue through Northern Hemisphere fall 2015, and around an
85% chance it will last through the 2015-16 winter.
Weekly updates of oceanic
and atmospheric conditions are available on the Climate Prediction Center
Niño/La Niña Current Conditions and Expert Discussions).