Tropical
Highlights - April 2015
During April
2015, sea surface temperatures (SSTs) remained above-average across the equatorial Pacific (Fig. T18, Table
T2). The latest monthly
Niņo indices were +1.2°C for the Niņo 4
region, +0.8°C
for the Niņo 3.4 region, and +1.4°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 above-average across the eastern and
east-central equatorial Pacific (Figs. T15, T16), and the corresponding sub-surface
temperatures were 1-6°C above average (Fig.
T17).
Also
during April, the low-level westerly wind anomalies continued across the equatorial
Pacific (Table T1,
Fig. T20) and upper-level easterly wind
anomalies continued over the central and eastern equatorial Pacific (Fig.T21). Meanwhile,
enhanced convection was observed across the central equatorial Pacific (Figs. T25, E3). Collectively, these oceanic and
atmospheric anomalies are consistent with weak 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