Tropical Highlights - January 2023

 

 

During January 2023, below-average sea surface temperatures (SSTs) persisted but weakened across the central and eastern equatorial Pacific (Fig. T18). The latest monthly Niño indices based on OISSTV2.1 were -0.2C for the Niño 1+2 region, -0.7C for the Niño 3.4 region and -0.6C for the Niño 4 region (Table T2). The depth of the oceanic thermocline (measured by the depth of the 20C isotherm) was below-average across the eastern equatorial Pacific (Figs. T15, T16). The corresponding sub-surface temperatures were 1-3C below-average (Fig. T17).

 

Also during January, the lower-level easterly winds and upper-level westerly winds were above-average across most of the equatorial Pacific (Table T1, Figs. T20, T21). Meanwhile, tropical convection was suppressed over much of the central and western equatorial Pacific and enhanced over western Indonesia (Fig. T25). Collectively, these oceanic and atmospheric anomalies were consistent with 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