Tropical Highlights

  Table of Atmospheric Indices  (Table 1)

  Table of Oceanic Indices  (Table 2)

  Time Series

  Time-Longitude Sections

  Mean & Anomaly Fields

  Appendix 1: Outside Contributions

Tropical Highlights

JULY 2010

Negative sea surface temperature (SST) anomalies continued to strengthen across the equatorial Pacific Ocean during July 2010 (Fig. T18).  The latest monthly SST indices were -0.9°C and -1.7°C for the Niño-3.4 and the Niño-1+2 regions, respectively (Table T2, Fig. T5). Consistent with this evolution, the oceanic thermocline (measured by the depth of the 20°C isotherm) was shallower than average across the central and eastern equatorial Pacific (Figs. T15 and T16), with sub-surface temperatures reaching 1°C to 5°C below average in the region (Fig. T17).

Also during July, equatorial low-level easterly trade winds and upper-level westerly winds remained stronger than average over the western and central Pacific (Table T1, Figs. T20 and T21). This wind pattern was associated with enhanced convection over Indonesia and suppressed convection across the western and central equatorial Pacific (Figs. T25 and E3). Collectively, these oceanic and atmospheric anomalies reflect developing and strengthening La Niña 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