A monthly summary of the climate in the tropical South Pacific islands, with an outlook for the coming months. This bulletin is a multi-national project with collaboration from a number of Pacific nations and support from various organisations.
The NINO3.4 Index anomaly (in the central Pacific) during March was -0.44˚C. This marked the first time since August 2020 that SSTs in this region were in the neutral range. The SOI value for March was +0.1 (in the neutral range).
During October, the NINO3.4 Index anomaly (central Pacific) was 0.86˚C. The NINO 1+2 Index (eastern Pacific) was 0.56 C. Upper oceanic heat content continued to decrease in the east central part of the Pacific basin.
El Nino –Southern Oscillation (ENSO) neutral conditions continued during December 2019. Both the Southern Oscillation Index (SOI) and sea surface temperatures (SSTs) remained on the El Niño side of neutral but weakened compared to previous months.
ENSO-neutral conditions continued during November 2019, although the Southern Oscillation Index (SOI) dipped into El Niño territory and sea surface temperatures (SSTs) were on the El Niño side of neutral.
Upper-oceanic heat content anomalies continued to decrease in the eastern and east-central equatorial Pacific during September. The core of the warm pool that had been associated with a central Pacific El Niño earlier in the year was located just west of the International Dateline.
During June 2019, the atmosphere continued to respond to a warm pool of water in the central and western Pacific, with above normal rainfall and cloud centred along and just west of the International Dateline.
During April 2019, the atmosphere once again responded to a warm pool of water in the central and western Pacific, withabove normal rainfall and cloud centred along and just west of the International Dateline