Highlights – April 2012
A transition from La Niña to ENSO-neutral
conditions occurred during April 2012, as reflected by by a decreased
magnitude of the negative surface temperature (SST) anomalies in the central equatorial Pacific, along
continued positive SST anomalies in the eastern equatorial Pacific (Fig. T18, Table T2). The latest monthly Niño indices were -0.4°C for
the Niño 3.4 region and +1.3°C for the Niño 1+2 region (Table T2,
Fig. T5). Consistent
with these conditions, the depth of the oceanic thermocline (measured
by the depth of the 20°C isotherm) became near-average
in the east-central equatorial Pacific and above-average in the far eastern
equatorial Pacific (Figs. T15, T16).
April, the equatorial low-level easterly trade winds were much weaker over the
central and west-central equatorial Pacific (Table T1, Fig. T20). Suppressed convection was seen
across the equatorial Indian Ocean and Indonesia (Figs. T25, E3). Collectively, these oceanic and
atmospheric anomalies reflect a transition from La Niña to ENSO-neutral conditions.
latest status of the ENSO cycle see the ENSO Diagnostic Discussion at: