Island Climate Update 54 - March 2005

Science Centres: Climate

March

Monthly climate

ENSO & SST

Forecast validation

Three-month outlook

Feature article

Tropical Pacific rainfall

Data sources

Natural Disasters: Fijian Case Study Irshad Ali, Save the Children Fiji Natural disasters are regular occurrences in Fiji and affect people across the country in many ways – cyclones, floods, landslides, and drought. Although these disasters have some links with seasons, they are not completely predictable, nor are they assiduously tracked or mapped.
Forecast validation Forecast period: December 2004 to February 2005 Enhanced convection and above average rainfall was expected over Eastern and Western Kiribati, Tuvalu, and Tokelau, extending to the Northern Cook Islands. Average or above average rainfall was expected in Pitcairn Island.
ENSO and Sea Surface Temperatures The tropical Pacific Ocean remains in a weak El Niño state, but there was a late surge of atmosphere-ocean coupling in February, resulting in large (probably short-term) changes in a number of indicators. The Southern Oscillation Index dropped dramatically from near zero in January to about -3 in February, when Tahiti recorded its lowest February monthly-mean sea level pressure, the lowest February value on record. Strong westerly zonal wind anomalies are evident in the west 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 54 – March 2005 February's climate: Very active South Pacific Convergence Zone, further north and east than usual. Strongly suppressed convection across Australia, the Southwest Pacific, and south and west of the Date Line. Four named tropical cyclones. ENSO and sea surface temperatures (SST): El Niño expected to continue to weaken over the coming months.
Climate developments in February 2005 There was a marked dipole in convection and very anomalous outgoing longwave radiation (OLR) over the Southwest Pacific in February. Strongly suppressed convection occurred over much of Australia and Indonesia, as well as Vanuatu, New Caledonia, and much of Fiji.
Tropical rainfall outlook: March to May 2005 Weakening El Niño conditions are expected to continue influencing the climate patterns in the Pacific region over the coming months. Enhanced convection is expected over the equatorial Pacific region, where rainfall is forecast to be above average for Western Kiribati.
Tropical Cyclone Update An active phase of the Madden-Julian Oscillation (MJO) moved across the Southwest Pacific during mid February, and helped trigger the development of tropical cyclones Meena, Nancy, and Olaf. All three affected the Cook Islands, with Olaf also affecting Samoa. Tropical cyclone Percy affected Tokelau on 26 February then tracked to Cook Islands before dissipating. It was the fourth tropical cyclone since the beginning of February, and the seventh named cyclone for the season. High frequencies of tropical cyclones east of the Date Line (6 of the 7 this season).
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