Synopsis: ENSO-neutral is expected to continue into the Northern Hemisphere summer 2014.
During December, ENSO-neutral persisted, as reflected by near-average sea surface temperatures (SST) across much of the equatorial Pacific Ocean (Fig. 1). The Nino indices in all of the regions were within ±0.5°C and showed only small changes during the month (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) decreased but remained above average (Fig. 3), following the passing of a downwelling oceanic Kelvin wave that had raised the sub-surface temperatures in November (Fig. 4). Also in December, slightly enhanced low-level trade winds were observed in the western tropical Pacific Ocean, while enhanced upper level westerly winds prevailed in portions of the eastern half of the basin. Convection was suppressed in the central equatorial Pacific and enhanced over Indonesia (Fig. 5). Collectively, these atmospheric and oceanic conditions reflect ENSO-neutral.
The majority of models predict that ENSO-neutral (Niño-3.4 index between -0.5oC and 0.5oC) will persist into the Northern Hemisphere summer 2014 (Fig. 6). While current forecast probabilities are still greatest for ENSO-neutral during summer, there is an increasing chance for the development of El Niño. The consensus forecast is for ENSO-neutral to continue into the Northern Hemisphere summer 2014 (see CPC/IRI consensus forecast).
This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web
site (El Niño/La Niña Current
Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the
Forecast Forum section of CPC's Climate
Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 6 February 2014. To receive
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