ENSO & SST

ENSO and Sea Surface Temperatures

SOI strongly negative

SST anomalies below average near the South American coast

The tropical Pacific remains in a near neutral state with mixed warming and cooling signals and a fluctuating SOI over the past few months. June SSTs were about 0.5°C above normal in the equatorial Pacific around Western and Eastern Kiribati.

The three month SOI (April-June) continues in the neutral range, at -0.7. For June, the NINO3 SST anomaly was about +0.4°C, and NINO4 was about +0.7°C. Three-month means for NINO3 and NINO4 were about +0.2°C and +0.5°C, respectively. Subsurface temperatures show a small positive anomaly remaining in the top 100 m near the Date Line, and a newly developed (but still weak) negative anomaly near 130°W.

June averaged OLR anomalies show an extensive region of enhanced convection west of the Date Line. Most models indicate neutral conditions continuing through the end of 2004, but with weakly positive SST anomalies forecast in the Nino3.4 region. The recent incoherence in oceanic and atmospheric signals in the tropical Pacific mean that there is a continuing need to monitor the ENSO situation closely.

Sea surface temperature anomalies (°C) for June 2004

Mean sea surface temperatures (°C) for June 2004