Island Climate Update 104 - May 2009

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 104 – May 2009
April’s climate
The South Pacific Convergence Zone (SPCZ) shifted in April, with only the eastern end positioned southwest of normal.
Very suppressed convection near Western Kiribati and south of the Equator extending east through Nauru and Eastern Kiribati.
Mostly well above normal rainfall for Tuvalu and Niue.
El Niño/Southern Oscillation (ENSO), seasonal rainfall

Climate developments in April 2009
Outgoing Long-wave Radiation anomalies for April 2009. (Click for enlargement and detail)
The South Pacific Convergence Zone (SPCZ) shifted east during April, with the northwestern part of the convective spur moving northeast of normal. However the southeastern portion of the SPCZ remained displaced southwest of its normal position for the month, contributing to high rainfall in the Austral Islands. A region of enhanced rainfall, partly due to intensified convection, was also observed in the north Tasman Sea and near New Caledonia last month.

Tropical rainfall and SST outlook: May to July 2009
Rainfall outlook map for May to July 2009.
Sea surface temperature outlook map for May to July 2009.
During May – July 2009, a region of suppressed convection is likely in the southwest Pacific encompassing Tokelau, Tuvalu, and the Northern Cook Islands, with below average rainfall expected for those areas. Near to below average rainfall is expected for Eastern Kiribati and the Marquesas. Near normal rainfall is forecast for Pitcairn Island and Samoa.

Tropical Pacific rainfall - April 2009
Territory and station name
April 2009 rainfall total (mm)
April 2009 percent of average
Australia
Cairns Airport
134
71
Townsville Airport
51
82
Brisbane Airport
60
67
Sydney Airport
153
156
Cook Islands
Penrhyn
N/A
N/A
Aitutaki
N/A
N/A
Rarotonga Airport
199
94
Fiji
Rotuma Island
277
94
Udu Point
216
78
Nadi Airport
73
46
Nausori
157
44
French Polynesia
Hiva Hoa, Atuona
211
121
Bora Bora
99
54
Tahiti – Faa’a
31
27
Tuamotu, Takaroa
81
68
Gambier, Rikitea
72
48
Tubuai
187
103
Rapa
61

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.
Your comments and ideas about the Island Climate Update are welcome.