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:

 

There is a 58% chance of El Niño during the Northern Hemisphere winter, which is favored to last into the Northern Hemisphere spring 2015.

 

Discussion:  

 

During October 2014, above-average sea surface temperatures (SST) increased slightly across the eastern half of the equatorial Pacific (Fig. T18).  The monthly Niño indices were between +0.5C (Niño-3.4) and +0.8C (Niño-1+2; Table T2). Subsurface heat content anomalies (averaged between 180-100W) were largely unchanged even as a new downwelling Kelvin wave increased temperatures at depth in the central Pacific (Fig. T17).  The monthly equatorial low-level winds were near average, although anomalous westerlies continued to emerge on occasion (Fig. T13).  Upper-level winds were also mostly average across the Pacific (Fig. T21).  The Southern Oscillation Index continued to be negative (Table T1), accompanied by mostly average rainfall near the Date Line and suppressed rainfall over Indonesia (Fig. T25).  Overall, several features across the tropical Pacific are characteristic of borderline El Niño conditions, but collectively, the combined atmosphere and oceanic state remains ENSO-neutral.

Similar to last month, most models predict El Niño to develop during October-December 2014 and to continue into early 2015 (Figs. F1-F13).  However, the ongoing lack of clear atmosphere-ocean coupling and the latest NCEP CFSv2 model forecast  have reduced confidence that El Niño will fully materialize (at least five overlapping consecutive 3-month values of the Niño-3.4 index at or greater than 0.5C).  If El Niño does emerge, the forecaster consensus favors a weak event. In summary, there is a 58% chance of El Niño during the Northern Hemisphere winter, which is favored to last into the Northern Hemisphere spring 2015

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