Tropical Highlights - October 2021

 

 

During October 2021, sea surface temperatures (SSTs) were below-average across much of the equatorial Pacific (Fig. T18). The latest monthly Ni�o indices were -0.2�C for the Ni�o 1+2 region, -0.8�C for the Ni�o 3.4 region and -0.7�C for the Ni�o 4 region (Fig. T5, Table T2). The depth of the oceanic thermocline (measured by the depth of the 20�C isotherm) was below-average across the eastern equatorial Pacific (Figs. T15, T16). The corresponding sub-surface temperatures were 1-7�C below-average (Fig. T17).

 

Also during October, the lower-level easterly winds and the upper-level westerly winds were above-average over parts of the equatorial Pacific (Table T1, Fig. T20, Fig. T21). Meanwhile, tropical convection was suppressed near and west of the Date Line (Figs. T25, E3). Collectively, these oceanic and atmospheric anomalies were consistent with La Ni�a 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