ENSO and Sea Surface Temperatures
Tropical Pacific in a neutral ENSO state
Equatorial SSTs warmed slightly
The tropical Pacific remains essentially in a neutral state with no change in the ENSO indices from last month. Equatorial SST anomalies have risen a little recently, and westerly zonal wind anomalies were evident across the western Equatorial Pacific.
The NINO3 SST anomaly rose slightly to about +0.7°C in October (from +0.3°C in September). NINO4 rose to +0.9°C (from +0.7°C in September). The three month (August-October) means were +0.4°C and +0.8°C for NINO3 and NINO4, respectively. SST anomalies have fluctuated near the South American coast, but anomalies have risen slowly in the central Equatorial Pacific over the last 2 to 3 months.
Subsurface ocean temperature anomalies are weakly positive above 100 m depth, and are weakly negative in the 100 m below that. Surface westerlies at Tarawa, Western Kiribati occurred in 27% of observations, their highest frequency since January this year.
Most global climate models indicate neutral conditions until early 2004.