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:  Final El Niño Advisory/ La Niña Watch

 

Outlook:

 

ENSO-neutral conditions are present and La Niña is favored to develop during the Northern Hemisphere summer 2016, with about a 75% chance of La Niña during the fall and winter 2016-17.

 

Discussion:  

 

            El Niño dissipated and ENSO-neutral conditions returned during over the past month, as indicated by the expansion of near-to-below average surface temperatures (SST) across the eastern equatorial Pacific Ocean (Fig. T18).  Other than the westernmost Niño-4 region, the Niño indices were close to zero for May (Table T2).  Below-average subsurface temperatures continued and extended to the surface across the eastern equatorial Pacific (Fig. T17).  For the first time in 2016, atmospheric anomalies over the tropical Pacific Ocean were also consistent with ENSO-neutral conditions.   The traditional and equatorial Southern Oscillation indices were near zero (Table T1 & Fig. T2), while the upper and lower-level winds were both near average across most of the tropical Pacific (Figs.T20-T21).  Convection was also near-average over the central tropical Pacific and over most of Indonesia (Fig. T25).  Collectively, these atmospheric and oceanic anomalies reflect a transition from El Niño to ENSO-neutral conditions.

Many models favor La Niña (3-month average Niño-3.4 index less than or equal to -0.5°C) by the Northern Hemisphere fall (Figs. F1-F13).  However, most dynamical models indicate La Niña onset as soon as the Northern Hemisphere summer, which is slightly favored by the forecaster consensus.  In contrast, many statistical models favor a later onset time, with about half indicating the persistence of ENSO-neutral conditions through the winter.  At this time, the forecasters are leaning toward a weak or borderline moderate La Niña if an event were to form.  Overall, ENSO-neutral conditions are present and La Niña is favored to develop during the Northern Hemisphere summer 2016, with about a 75% chance of La Niña during the fall and winter 2016-17

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