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: Not Active

 

Outlook:

 

ENSO-neutral is favored (50 to ~55% chance) through the Northern Hemisphere fall 2017.

 

Discussion:  

 

During May, ENSO-neutral continued, though sea surface temperatures (SSTs) were above average in the east-central Pacific Ocean (Fig. T18). The monthly Niño index values were near +0.5°C in most of the Niño regions, except for the easternmost Niño-1+2 region, which was at +0.8°C (Table T2). The upper-ocean heat content anomaly increased during May, reflecting the expansion of above-average sub-surface temperatures across the central and eastern Pacific (Fig. T17) in association with a downwelling oceanic Kelvin wave.  While ocean temperatures were elevated, the atmosphere was close to average. Atmospheric convection anomalies were weak over the central tropical Pacific and Maritime Continent (Fig. T25), while the lower-level and upper-level winds were near average over most of the tropical Pacific (Fig. T20, Fig. T21).  Both the Southern Oscillation Index (SOI) and Equatorial SOI were also near zero (Tables T1).  Overall, the ocean and atmosphere system remains consistent with ENSO-neutral.

Many models predict the onset of El Niño (3-month average Niño-3.4 index at or greater than 0.5°C) during the Northern Hemisphere summer (Figs. F1-F13). However, the NCEP CFSv2 and most of the models from the latest runs of the North American Multi-Model Ensemble (NMME) are now favoring the continuation of ENSO-neutral.  These predictions, combined with the near-average atmospheric conditions over the Pacific, have resulted in slightly more confidence for the persistence of ENSO-neutral (50 to ~55% chance). However, chances for El Niño remain elevated (35-50%) relative to the long-term average into the fall.  In summary, ENSO-neutral is favored (50 to ~55% chance) through the Northern Hemisphere fall 2017

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