Tropical
Highlights - December 2023
During December
2023, sea surface
temperatures (SSTs) remained well above-average across the central and eastern equatorial Pacific (Fig. T18).
The latest monthly
Niņo indices were +1.4C for the Niņo 1+2
region, +2.0C
for the Niņo 3.4 region and +2.1C for the Niņo 3 region (Table T2). The depth of the oceanic thermocline
(measured by the depth of the 20C isotherm) was above-average across the central
and eastern equatorial Pacific (Figs. T15, T16). The
corresponding sub-surface temperatures were 1-5C above-average in the far
eastern equatorial Pacific (Fig. T17).
Also during December, the
lower-level wind anomalies were westerly over much of the central and eastern equatorial
Pacific, while the upper-level wind anomalies were easterly over the eastern equatorial
Pacific (Table T1,
Figs. T20, T21). Meanwhile, tropical convection was enhanced around
the Date Line and suppressed over Indonesia (Fig. T25). Collectively, these oceanic
and atmospheric anomalies were consistent with strong El Niņo conditions.
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