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 ENSO‑CLIPER statistical model (Knaff and Landsea 1997, Wea. Forecasting, 12, 633‑652) are shown in Fig. F11.  Niño 3.4 predictions are summarized in Fig. F12, 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 during the Northern Hemisphere winter 2019-20 (~70% chance), continuing through spring 2020 (60 to 65% chance).

 

Discussion:  

 

Near-to-above average sea surface temperatures (SSTs) were observed in the east-central tropical Pacific Ocean during October (Fig. T18).  The monthly SST indices in the westernmost Niño-4 and Niño-3.4 regions were +1.0°C and +0.6°C, respectively, while farther east in the Niño-3 and Niño-1+2 regions they were near or below average (+0.2°C and -0.8°C respectively; Table T2).  The subsurface temperature anomalies (averaged across 180°-100°W) were above average during the month, as a downwelling oceanic Kelvin wave that began in September continued progressing eastward into the eastern Pacific (Fig. T17).  Low-level winds were near average during October (Fig. T20), while easterly upper-level wind anomalies were observed over the eastern Pacific (Fig. T21).  Finally, tropical convection was suppressed near the Date Line and also over Indonesia, while somewhat enhanced convection prevailed over the western Pacific, northeast of Papua New Guinea (Fig. T25).  Overall, despite the recent anomalous warming across the east-central equatorial Pacific, the overall oceanic and atmospheric system reflected ENSO-neutral. 

The majority of models in the IRI/CPC plume (Figs. F1-F12) continue to favor ENSO-neutral (Niño-3.4 index between -0.5°C and +0.5°C) through the Northern Hemisphere spring.  Many dynamical forecast models, including the NCEP CFSv2, suggest Niño-3.4 SST index values will remain near +0.5°C during November before decreasing toward zero.  Forecasters believe this recent warmth reflects sub-seasonal variability and is not indicative of an evolution toward El Niño.  The chances for El Niño are predicted to be near 25% during the winter and spring.  In summary, ENSO-neutral is favored during the Northern Hemisphere winter 2019-20 (~70% chance), continuing through spring 2020.

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