Island Climate Update 52 - January 2005

Facing weather and climate variability with indigenous knowledge
P.F. Lefale and D.N.T. King, NIWA
In the tropical southwest Pacific, measurements of weather and climate conditions by European scientists began in the late 1800s, with the first observing stations established in New Caledonia in 1863 and Samoa in 1890. Since then, scientific observations and research into understanding the weather and climate of the region have advanced at a rapid pace in line with the information and technological era.

Forecast validation
Forecast period: October to December 2004
Enhanced convection was expected with above average rainfall over Eastern and Western Kiribati, and areas of above or average rainfall extending to the Solomon Islands, Tuvalu, and Tokelau, as well as Pitcairn and the Austral Islands. Areas of suppressed convection with average or below average rainfall were expected in Papua New Guinea, New Caledonia, Vanuatu, Samoa, Tonga, the Southern Cook Islands, and the Marquesas Islands.

ENSO and Sea Surface Temperatures
The tropical Pacific Ocean remains in a weak El Niño state. The NINO3.4 average anomaly was about +0.8°C in December, similar to the October/November values. Subsurface temperature anomalies are positive (up to +3°C) in the top 100 m in the eastern Equatorial Pacific.

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 52 – January 2005
December’s climate: The South Pacific Convergence Zone (SPCZ) extended from the Solomon Islands towards Samoa – Northern French Polynesia also affected. Tropical Cyclone Judy brought high rainfall to the Tuamotu Islands of French Polynesia.

Climate developments in December 2004
The South Pacific Convergence Zone (SPCZ), although not very active about and west of the Date Line, extended from the Solomon Islands east towards Samoa, including Tuvalu, Rotuma Island (northern Fiji), and Wallis and Futuna. Northern French Polynesia was also affected by the SPCZ, where it was more active than usual. Rainfall was well above average at Takaroa, in the Tuamotu Islands of French Polynesia, mainly because of high rainfall associated with tropical cyclone Judy in the third week of December.

Tropical rainfall outlook: January to March 2005
The tropical Pacific Ocean is still in a weak El Niño state and this will continue to influence rainfall patterns in the Pacific region over the next three months.
Enhanced convection is expected in the equatorial region of Western and Eastern Kiribati and Tuvalu where rainfall is forecast to be above average.

Tropical pacific rainfall - December 2004
Territory and station name
December 2004 rainfall total (mm)
Long-term average (mm)
December 2004 percent of average
Lowest on record (mm)
Highest on record (mm)
Records began
American Samoa
Pago Pago Airport
263.9
364
73
1966
Australia
Cairns Airport
252.6
184
137
9
919
1941
Townsville Airport
112.8
131
86
0
458
1940
Brisbane Airport
255.6
126
203
30
438
1929
Sydney Airport
91.6
76
121
1929
Cook Islands
Rarotonga Airport
71.5
188
38
11
653
1929
Fiji
Rotuma
327.2
285
115

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