Island Climate Update 27 - December 2002

El Niño Impacts in the Pacific, now and for the Southern Hemisphere Summer
Ashmita Gosai, Andrew Watkins, Luc Maitrepierre, and Stuart Burgess
Figure 1. New Caledonia May to November 2002 rainfall compared to the 1971–2000 normal
Figure 2. Tarawa, Kiribati, 2002 monthly rainfall Actual rainfall is shown by the bars. The solid line shows the normal rainfall.
Figure 3.

Forecast validation
Forecast period: September to November 2002
The influence of the El Niño was expected to have a significant influence on rainfall anomalies, with more convergence and a tendency towards above average rainfall for Kiribati, Tuvalu, and Tokelau. Wallis and Futuna, and Pitcairn Island were also expected to receive above average or average rainfall. Below average or average rainfall was expected in a broad area from Papua New Guinea southeast to New Caledonia, across to Tonga and the Southern Cook Islands.

An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
Number 27 – 10 December 2002
November’s Climate: The moderate El Niño episode is continuing to affect Southwest Pacific rainfall patterns, with enhanced convection and above average rainfall over much of Kiribati, and contrasting areas of suppressed convection and well below average rainfall from Queensland across to New Caledonia.

ENSO and Sea Surface Temperatures
El Niño expected to weaken in the Autumn of 2003
Equatorial Pacific SSTs continue to warm
Sea surface temperature anomalies across the Equatorial Pacific are very positive from the date line across to the South America.
The NINO3 region and NINO4 regional sea surface temperature (SST) anomalies were around +1.6°C and +1.7°C respectively in November. The September – November 2002 mean SSTs were about +1.3°C for NINO3, and +1.4°C in the NINO4 region.

El Niño continues to enhance convection and rainfall over Kiribati
Extremely low rainfall in New Caledonia and parts of French Polynesia
The SPCZ remained near its average location about and west of the date line, with enhanced convection from the Solomon Islands across to Tuvalu, northern Vanuatu, and the sea area northwest of Fiji.

Rainfall outlook for December 2002 to February 2003
The El Niño related convection and tendency towards above average rainfall is expected to persist in equatorial countries, including Tuvalu and Tokelau
Rainfall should trend below average from the Solomon Islands, southeast to the Southern Cook Islands
The region of enhanced convection in the NINO3 region should continue to persist from December 2002 through February 2003, resulting in a high likelihood of above average rainfall in both Western and Eastern Kiribati.
Average or above average rainfall is expected in Tuvalu and Tokelau.

Sources of South Pacific rainfall data
This bulletin is a multi-national project with important collaboration from the following Pacific nations:
American Samoa
Australia
Cook Islands
Fiji
French Polynesia
Kiribati
New Caledonia
New Zealand
Niue
Papua New Guinea
Pitcairn Island
Samoa
Solomon Islands
Tokelau
Tonga
Tuvalu
Vanuatu
Requests for Pacific island climate data should be directed to the Meteorological Services concerned.
Acknowledgements
This bulletin is made possible with financial support from the New Zealand Agency for International Development (NZAID), Wellington, New Zealand, wi