Tropical Highlights
DECEMBER 2009
Forecast Forum
Sea surface
temperature (SST) anomalies during December 2009 continued to increase across
much of the central and eastern equatorial Pacific Ocean (Fig. T18). Consequently,
all of the monthly Niņo-region
SST indices were above +1.4°C, except for the Niņo1+2 index (Table
T2, Fig. T5). The oceanic
thermocline, measured by the depth of the 20°C isotherm,
remained deeper than average across the equatorial Pacific (Figs. T15,
T16), with sub-surface temperatures in the
eastern Pacific reaching +2°C
to +5°C above average (Fig.
T17).
During
December 2009, convection was suppressed across Indonesia and enhanced over the
western and central equatorial Pacific (Figs.
T25, T26
and E3). Equatorial low-level
westerly and upper-level easterly wind anomalies (Figs.
T20 and T21)
were also consistent with El Niņo. Overall,
the oceanic and atmospheric anomalies reflected
a strong El Niņo.
For
the latest status of the ENSO cycle see the ENSO Diagnostic Discussion at:
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/index.html
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