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:

 

ENSO-neutral is favored through Northern Hemisphere summer 2018, with the chance for El Niño increasing to about 65% during fall, and to about 70% during winter 2018-19.

 

Discussion:  

 

ENSO-neutral continued during June, as indicated by slightly above-average sea surface temperatures (SSTs) across the central and eastern equatorial Pacific (Fig. T18). The monthly Niño indices were between +0.2°C and +0.3°C, except for the Niño-1+2 index, which was -0.6°C (Table T2).  Positive subsurface temperature anomalies (averaged across 180°-100°W) continued over the past month, and the volume of anomalous warmth now extends to the surface in the eastern part of the basin (Fig. T17). Convection remained suppressed near the Date Line and was near-average over Indonesia (Fig. T25).  Low-level winds were near average across the equatorial Pacific Ocean, except in the east-central Pacific, where anomalies were westerly (Fig. T20). At upper-levels, anomalous easterly winds were present over the east-central Pacific and near the International Date Line (Fig. T21). Overall, the oceanic and atmospheric conditions reflected ENSO-neutral. 

           

The majority of models in the IRI/CPC plume predict ENSO-neutral to continue through the Northern Hemisphere summer 2018, with El Niño most likely thereafter (Figs. F1-F13). The forecaster consensus favors the onset of El Niño during the Northern Hemisphere fall, which would then continue through winter. These forecasts are supported by the anomalous subsurface warmth across the eastern half of the tropical Pacific Ocean.  In summary, ENSO-neutral is favored through Northern Hemisphere summer 2018, with the chance for El Niño increasing to about 65% during fall, and to about 70% during winter 2018-19.

 

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