Island Climate Update 14 - November 2001

Fewer tropical cyclones are likely in the Pacific this year
For most South Pacific countries the chances of tropical cyclone activity are lower than normal for the November – January period
Many Pacific Island countries are likely to experience fewer than average tropical cyclones this season (see Table below). This pattern is expected because Southern Oscillation conditions affecting the tropical Pacific region are neutral, and are expected to remain so over the early part of the cyclone season.

Forecast validation
Forecast period: August to October
Average to above average rainfall was expected over many islands from Papua New Guinea across to the Southern Cook Islands. Below average rainfalls were forecast for Samoa and the Tokelaus, with average to below average rainfall in Kiribati, Tuvalu, the Northern Cooks and Pitcairn Island. Near average rainfalls were expected in most other parts of the tropical South West Pacific.
This scenario was correct for many islands north of 15°S and west of 180°, including Eastern Kiribati.

ENSO and Sea Surface TEmperatures
Warmer than average seas around Kiribati
SST anomalies have still shown little change since July, with an area of warm 30°C surface waters and positive SST anomalies (at least 1.0°C above average) between the Solomon Islands and Western Kiribati. SST anomalies also continued 1.0°C or more above average about and to the east of the Tuamotu Islands. A tongue of cooler equatorial waters remains off the South American coast, enhancing the east-west temperature gradient somewhat.

Climate developments in October 2001
Low rainfall continues in the Coral Sea, Tonga and Niue
Very wet in central Vanuatu and parts of Fiji
Rainfall continued well below average during October in the Coral Sea, with totals ranging from 5 to 50% of average. Low rainfall persisted for the second month running throughout central Tonga and Niue, with totals less than 50% of average.

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 14 – 12 November 2001
October’s Climate: Very dry conditions have now persisted for many months in parts of the Coral Sea. Low rainfall also continued throughout central Tonga and Niue with totals less than 50% of average. Other regions with well below average October rainfall were Kiribati, northern Vanuatu, and the Marquesas.

Rainfall outlook for November 2001 to January 2002
Average to below average rainfall in the central Pacific from Tuvalu to the Marquesas
Average to above average rainfall in some areas west of the Dateline
The SPCZ is expected to remain south of its normal position east of the Dateline, with slightly enhanced trade winds in the central Pacific, resulting in average to below average rainfall throughout Tuvalu, Eastern Kiribati, the northern Cook Islands, Samoa and the Marquesas islands of French Polynesia.

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