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Climate Diagnostics Bulletin
Climate Diagnostics Bulletin - Home Climate Diagnostics Bulletin - Forecast Climate Diagnostics Bulletin - Extratropics


  Tropical Highlights

  Table of Atmospheric Indices  (Table 1)

  Table of Oceanic Indices  (Table 2)

  Time Series

  Time-Longitude Sections

  Mean & Anomaly Fields

  Appendix 1: Outside Contributions

Tropical Highlights


The pattern of tropical sea surface temperature (SST) anomalies

Tropical Highlights - December 2018



Sea surface temperatures (SSTs) remained above-average across the equatorial Pacific during December 2018 (Fig. T18, Table T2). The latest monthly Niņo indices were +0.8°C for the Niņo 1+2 region, and +1.0°C for the Niņo 3.4 and Niņo 3 regions (Table T2, Fig. T5). The depth of the oceanic thermocline (measured by the depth of the 20°C isotherm) was above-average across the eastern equatorial Pacific (Figs. T15, T16), and the corresponding sub-surface temperatures were 1-4°C above average (Fig. T17).


Also during December, the lower-level easterly winds were slightly weaker-than-average (indicated by westerly anomalies) over the eastern equatorial Pacific (Table T1, Fig. T20), while the upper-level westerly winds anomalies were near-average across the western and central equatorial Pacific (Fig. T21). Meanwhile, tropical convection was near-average over Indonesia and enhanced just west of the Date Line (Figs. T25, E3). Collectively, these oceanic and atmospheric anomalies reflect ENSO-neutral, but with continued evolution toward El Niņo.


For the latest status of the ENSO cycle see the ENSO Diagnostic Discussion at:

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