Island Climate Update 85 - October 2007

Tropical Cyclone guideance for the 2007-08 season
Average annual number of tropical cyclones, weak Nov-May La Niña periods, from 1969/70-2006/07.
Dr Jim Salinger, Stuart Burgess, and Dr Jim Renwick, NIWA
Lower risk of tropical cyclones east of the Date Line but all islands should remain vigilant.
For the coming tropical cyclone season, from November 2007-May 2008, we are likely to see an average risk of occurrence for those areas of the South Pacific near the Date Line. These countries include Tuvalu, Fiji, Wallis and Futuna, Tonga, and Niue.

Climate developments in September 2007
Outgoing Long-wave Radiation anomalies for September 2007. (Click for enlargement and detail)
The South Pacific Convergence Zone (SPCZ) extended from Papua New Guinea to the region south of Tonga, including the Solomon Islands, Vanuatu, and Fiji, being very active and much further southwest than normal for the time of year. An elongated region of suppressed convection continued to persist along the equator from Western and Eastern Kiribati and further east (north of the Equator) toward the coast of South America.

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 85 – October 2007
September’s climate
The South Pacific Convergence Zone (SPCZ) over Papua New Guinea to the region south of Tonga; very active and further southwest than normal
Suppressed convection over Western and Eastern Kiribati and further east
Record September rainfall in Vanuatu, New Caledonia and parts of Fiji; well below average rainfall in Kiribati, Tuvalu, northern Cook Islands a

Tropical rainfall outlook: October to December 2007
Rainfall outlook map for October to December 2007. (Click for enlargement)
A La Niña-like pattern, with the SPCZ displaced further southwest than usual.

Tropical Pacific rainfall - September 2007
Territory and station name
September 2007 rainfall
total (mm)
September 2007 percent
of average
Australia
Cairns Airport
4.0
11
Townsville Airport
42.0
18
Brisbane Airport
40.2
114
Sydney Airport
40.6
65
Cook Islands
Penrhyn
24.0
16
Rarotonga Airport
65.0
60
Fiji
Rotuma
162.4
68
Udu Point
328.8
291
Nadi
217.5
311
Nausori
308.5
187
Ono-I-Lau
210.3
194
French Polynesia
Hiva Hoa, Atuona
162.4
68
Bora Bora Motu
52.6
291
Tahiti – Faa’a
38.0
75
Tuamotu, Takaroa
102.4
124
Gambier, Rikitea

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 produced by NIWA and made possible with financial support from the New Zealand Agency for International Development (NZAID), with addi