Island Climate Update 20 - May 2002

23 March 2007 - 12:24pm

Science Centres: Climate

May

Monthly climate

ENSO & SST

Forecast validation

Three-month outlook

Feature article

Data sources

Feature article
Tropical cyclones April was a ‘quiet’ month There were no further tropical cyclones in the Southwest Pacific during April. Five tropical cyclones have occurred so far this season, which is the same number as last season and well below average. There is a 50 percent chance of another tropical cyclone occurring in May. ENSO update No further progress towards an El Niño in the last month There is still about a 60% chance of an El Niño event affecting the Southwest Pacific climate by September this year.

Forecast validation
Forecast validation Forecast period: February to April 2002 The SPCZ was expected to be more active and further south of its usual position west of the date line, with enhanced trade winds in the east. Areas of above average rainfall were forecast for parts of the Solomon Islands and Fiji. Below average rainfall was forecast for many islands from Western Kiribati across to the Marquesas Islands.

ENSO & SST
ENSO and Sea Surface Temperatures In the tropical Southwest Pacific, a band of much warmer than usual water at the surface (at least 1.0°C above average) extends from the Solomon Islands southeast to affect Vanuatu, Fiji, Tonga, Niue, and the region south of the Southern Cook Islands. Surface waters at least 1.0°C above average also encompass the region from central French Polynesia to the east of Pitcairn Island, as well as Western Kiribati.

May
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 20 – 8 May 2002 April’s Climate: The SPCZ was displaced further south than average about and west of the date line, with a large area of enhanced convection affecting Fiji and Tonga. Another convective band extended from the Southern Cook Islands to the south of French Polynesia. Rainfall was above average at many locations within these convective areas.

Monthly climate
Climate developments in April 2002 Active convection over Fiji and Tonga High rainfall in parts of New Caledonia Low rainfall from the Solomon Islands across to the northern Cook Islands The SPCZ was displaced further south than average about and west of the date line, with a large area of enhanced convection affecting Fiji and Tonga, with another convective band further east extending from the Southern Cook Islands to the south of French Polynesia.

Three-month outlook
Rainfall outlook for May to July 2002 Above average rainfall in equatorial latitudes from west to east, including Tonga Average to below average rainfall from Tokelau to the Marquesas Islands Mainly average rainfall in other areas The South Pacific Convergence Zone was further south than average about and west of the date line during April, lying across southern Fiji, and extending east to the Southern Cook and Austral Islands. Rainfall is projected to be above average in Western and Eastern Kiribati, as well as Tonga.

Data sources
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