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 Watch

 

Outlook:

 

The chance of El Niño is about 70% during the Northern Hemisphere summer and is close to 80% during the fall and early winter.

 

Discussion:  

 

            During June 2014, above-average sea surface temperatures (SST) were most prominent in the eastern equatorial Pacific, with weakening evident near the International Date Line (Fig. T18).  This weakening was reflected in a decrease to +0.6°C in the Niño-4 index (Table T2).  The Niño-3.4 index remained at +0.5°C for the month, while the easternmost Niño-3 and Niño-1+2 indices were +0.9°C or greater.  Subsurface heat content anomalies (averaged between 180º-100ºW) have decreased substantially since late March 2014 and are now near average.  However, above-average subsurface temperatures remain prevalent near the surface (down to 100m depth) in the eastern half of the Pacific (Fig. T17).  The upper-level and low-level winds over the tropical Pacific remained near average, except for low-level westerly anomalies over the eastern Pacific (Fig. T20, T21). Convection was enhanced near and just west of the Date Line and over portions of Indonesia (Fig. T25).  Still, the lack of a clear and consistent atmospheric response to the positive SSTs indicates ENSO-neutral. 

Over the last month, no significant change was evident in the model forecasts of ENSO, with the majority of models indicating El Niño onset within June-August and continuing into early 2015 (Figs. F1-F13). The chance of a strong El Niño is not favored in any of the ensemble averages for Niño-3.4.  At this time, the forecasters anticipate El Niño will peak at weak-to-moderate strength during the late fall and early winter (3-month values of the Niño-3.4 index between 0.5°C and 1.4°C).  The chance of El Niño is about 70% during the Northern Hemisphere summer and is close to 80% during the fall and early winter.

Weekly updates of oceanic and atmospheric conditions are available on the Climate Prediction Center homepage (El Niño/La Niña Current Conditions and Expert Discussions).