Tropical Highlights
NOVEMBER 2009
Forecast Forum
Sea surface
temperature (SST) anomalies during November 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 +1.3°C, except for the Niņo1+2 index, which increased
to +0.5°C
(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 +4°C
to +6°C above average (Fig.
T17). Overall,
the oceanic and atmospheric anomalies reflected
a moderate strength El Niņo.
The
tropical circulation during November also featured intra-seasonal activity
associated with the Madden-Julian
Oscillation (MJO)
(Figs. T12),
which masked the El Niņo-related pattern of enhanced convection over the
central equatorial Pacific (Figs. T25
and E3). The MJO also
contributed to the variations of the lower-level
and upper-level wind anomalies over the equatorial Pacific (Figs. T20, T21 and
T13).
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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