Highlights – October 2011
conditions strengthened during October 2011 as sea surface temperature
anomalies were well below -0.5°C across the eastern and central equatorial
Pacific Ocean (Fig. T18, Table T2). The
latest monthly Niño indices were -1.0°C for the Niño 3.4 region and -0.6°C for
the Niño 1+2 region (Table T2, Fig. T5).
Consistent with these conditions, the oceanic thermocline (measured by the
depth of the 20°C isotherm) remained shallower
than average in the east-central equatorial Pacific (Figs. T15 and T16), where
corresponding sub-surface temperatures were 1-5°C below average (Fig. T17).
October, the equatorial low-level easterly trade winds and upper-level westerly
winds were stronger than average over the western equatorial Pacific (Table T1, Figs. T20 and
T21). Convection remained suppressed near the Date
Line (Figs. T25
and E3) but was near-average over
Indonesia, which reflected the effect of the intraseasonal oscillation seen in
October (Fig. T12).
Collectively, these oceanic and atmospheric anomalies reflect a strengthening
of La Niña conditions.
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