Island Climate Update 40 - January 2004

Pacific Island Training Institute on Climate and Extreme Events
The University of the South Pacific (USP), the East-West Center (EWC) and the National Institute of Water and Atmospheric Research (NIWA) will convene a two-week Pacific Island Training Institute on Climate and Extreme Events from 15–28 June 2004 at the Suva campus of the University of the South Pacific. The Asia-Pacific Network for Global Change Research (APN) and the U.S.

Forecast validation
Forecast period: October to December 2003
Average or above average rainfall was expected in Samoa. A large area of suppressed convection in the equatorial region was expected to extend south, to affect areas west of the Date Line, with below average rainfall in Western and Eastern Kiribati, and average or below average rainfall in New Caledonia, and Vanuatu, as well as the Marquesas Islands. Average rainfall was expected elsewhere in the region.

Tropical Cyclone Update
‘Heta’, the first severe tropical cyclone (category 5 – most severe) of the season, originated from a disturbance north of Fiji on 28 December. It moved to develop into a tropical cyclone just west of Atafu, the northernmost part of the Tokelau Islands on 2 January.
Heta continued to track south, passing west of Samoa on 5 January, and then southeast, with sustained winds near its centre exceeding 220 km/h.

ENSO and Sea Surface Temperatures
Pacific in a neutral ENSO state
Westerly surface wind anomalies
The Equatorial Pacific continues in a neutral state. Positive equatorial SSTs have eased
recently, but are still higher than normal, especially in the west. The mean SOI for December was +0.9, and 0.0 for October–December. The NINO3 SST anomaly for December was about +0.6°C and NINO4 is around +0.9°C (3-month means are +0.7°C and +1.0°C, respectively).

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 40 – 8 January 2004
December’s climate: Enhanced convection was associated with the monsoon over Indonesia, northern Australia, and Papua New Guinea, which merged with the Inter-tropical convergence zone (ITCZ) north of the equator and the South Pacific Convergence Zone (SPCZ) to the southeast.

Climate developments in December 2003
Active SPCZ further south than usual
Below average rainfall persists over much of the equatorial southwest Pacific
A large region of enhanced convection was associated with the monsoon over Indonesia, northern Australia, and Papua New Guinea. This extended east to merge with the ITCZ north of the equator and the SPCZ to the southeast.

Rainfall outlook for January to March 2004
Average or above average rainfall likely from the Solomon Islands east southeast to the Austral Islands
Below average rainfall likely in the Marquesas Islands
Near average rainfall elsewhere in the region
Enhanced convection is expected in parts of the tropical Southwest Pacific resulting in average or above average rainfall from the Solomon Islands trending east to the Austral Islands, including Samoa, the Northern Cook Islands and the Society and Austral Islands.
However, below average rainfall is expected for the Marquesas Islands.

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