Island Climate Update 16 - January 2002

Science Centres: Pacific Rim

January

Monthly climate

ENSO & SST

Forecast validation

Three-month outlook

Feature article

Data sources

Tropical Cyclones By Stuart Burgess, Dr Jim Renwick and Dr Jim Salinger, NIWA Three tropical cyclones so far The tropical cyclone season is now well underway, with three cyclones having occurred so far this season. ‘Trina’ occurred from 30 November through 2 December, affecting the Southern Cook Islands. Winds gusted to 104 km/h at Rarotonga Airport, and floods resulted because of heavy rainfall.
Forecast validation Forecast period: October to December Areas of average to above average rainfall were expected from Papua New Guinea southeast to the Austral Islands of French Polynesia, as well as western Kiribati. Average to below average rainfalls were forecast for Tuvalu to the Marquesas, including the Samoa, Tokelau, Eastern Kiribati, the Northern Cooks, and Pitcairn Island.
ENSO and Sea Surface TEmperatures Seas continue warming in the west SST anomalies were still weak across the Equatorial Pacific, but the cooler east- warmer west temperature gradient remained. SST models showed positive anomalies building in the west around the Solomon Islands and Vanuatu (to at least 1.0°C above average), and particularly around New Caledonia (at least 1.5°C above average). Anomalies continued above average east of the Tuamotu Islands and around Pitcairn Island. The warmest surface waters (30-31°C) occurred around the Solomon Islands.
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 16 – 10 January 2002 December's Climate: The South Pacific Convergence Zone was very active bringing high rainfall to many islands from north of Papua-New Guinea, east through Nauru, Western Kiribati, Tuvalu and Tokelau, and southeast to the Northern Cook Islands and much of French Polynesia. Rainfall was also high over Samoa, northern Tonga, and the North Island of New Zealand.
Climate developments in November 2001 Very active SPCZ brings high rainfall to many islands Low rainfall from coastal Queensland in Australia, across to Vanuatu A very strong El Niño-like OLR/rainfall anomaly pattern was evident in December in the west of the region, as a broad band of enhanced convection occurred in equatorial regions from north of Papua-New Guinea east through Nauru, Western Kiribati, Tuvalu and Tokelau, and southeast to the Northern Cook Islands and much of French Polynesia.
Rainfall outlook for January to March 2002 SPCZ more active than usual Above average to average rainfall in western equatorial latitudes southeast to Samoa, Tonga and Niue: average to below average rainfall in the equatorial east, and from northern Queensland across to Vanuatu The trade winds are now only slightly enhanced east of the dateline, having weakened to the west with westerly wind anomalies. Thus the SPCZ is now displaced further north of its normal location for the time of year, and is expected to be active during the next few months.
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