Synopsis: ENSO-neutral is favored for Northern Hemisphere winter 2012-13 and into spring 2013.
During November 2012, the Pacific Ocean reflected ENSO-neutral conditions. Equatorial sea surface temperatures (SST) anomalies were slightly positive across all of the tropical Pacific Ocean except for the far eastern portion (Fig. 1), as also indicated in the Niño indices (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) was also slightly above average (Fig. 3), with largest amplitude in the east-central part of the basin (Fig. 4). Despite the subsurface and surface Pacific Ocean being slightly warmer than average, the tropical atmosphere remained in an ENSO-neutral state. Upper-level and lower-level zonal winds were near average, and convection was slightly suppressed over the eastern and central tropical Pacific (Fig. 5). Thus, both the atmosphere and ocean indicated ENSO-neutral conditions.
Relative to last month, the SST model predictions increasingly favor ENSO-neutral, with many remaining just slightly above average in the Niño-3.4 region through the Northern Hemisphere winter 2012-13 and into spring 2013 (Fig. 6). While the tropical atmosphere and especially the ocean suggested borderline ENSO-neutral/ weak El Niño conditions at times from July to September, these signs have now largely dissipated. Therefore, it is considered unlikely that a fully coupled El Niño will develop during the next several months. ENSO-neutral is now favored through the Northern Hemisphere winter 2012-13 and into spring 2013 (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 10 January 2013. To receive
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