Tropical
Highlights - January 2018
Sea surface
temperatures (SSTs) during January 2018 were below-average across the central and eastern equatorial
Pacific (Fig. T18,
Table T2). The latest monthly
Niņo indices were -0.3°C for the Niņo 4
region, -0.8°C
for the Niņo 3.4 region, and -0.8°C for the Niņo 1+2 region (Table
T2, Fig. T5). The depth of the oceanic thermocline
(measured by the depth of the 20°C isotherm) was below-average over the eastern
equatorial Pacific (Figs. T15, T16), and
the corresponding sub-surface temperatures were 1-4°C below average (Fig. T17).
Also during January, the lower-level
trade winds were above-average across the western and central equatorial
Pacific while the upper-level westerly winds were above-average over the
central and eastern equatorial Pacific (Table
T1, Figs. T20, T21). Meanwhile, convection was enhanced across
Indonesia and western equatorial Pacific and suppressed over the central
equatorial Pacific (Figs. T25, E3).
Collectively, these oceanic and atmospheric anomalies reflect La Niņa
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