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 85% chance it will last into early spring 2016.

 

Discussion:  

 

            During July, sea surface temperatures (SST) anomalies were near +1.0°C in the central equatorial Pacific Ocean, and in excess of +2.0°C across the eastern Pacific (Fig. T18). SST anomalies increased in all Niño regions, except for Niño-4, which decreased slightly since last month (Table T2). Positive subsurface temperature anomalies strengthened in the central and east-central equatorial Pacific during the month, in association with the eastward movement of a downwelling oceanic Kelvin wave (Fig. T17). The atmosphere remained coupled to the oceanic warming, with significant low-level westerly wind anomalies continuing from the western to east-central equatorial Pacific, along with anomalous upper-level easterly winds (Figs.T20, T21). Also, 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 a significant and strengthening El Niño.

All models surveyed predict El Niño to continue into the Northern Hemisphere spring 2016, and all multi-model averages predict a strong event at its peak in late fall/early winter (3-month values of the Niño-3.4 index of +1.5°C or greater; Figs. F1-F13). At this time, the forecaster consensus unanimously favors a strong El Niño, with peak 3-month SST departures in the Nino 3.4 region potentially near or exceeding +2.0°C. Overall, there is a greater than 90% chance that El Niño will continue through Northern Hemisphere winter 2015-16, and around an 85% 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).