Monthly climate

Climate developments in August 2005

The South Pacific Convergence Zone (SPCZ) extended from Papua New Guinea to the region south of Tuvalu (due to enhanced convection near Papua New Guinea), with areas of associated convection northeast of Fiji and also towards Pitcairn Island. North of the equator, the Intertropical Convergence Zone (ITCZ) was quite active, extending eastward from the region near the Marshall Islands across to South America. A large area of suppressed convection existed over Western and Eastern Kiribati, extending south to include Tokelau and the Northern Cook Islands.

Rainfall was more than 200% of average at several locations in New Caledonia (after heavy falls over 9-13 August) and also in parts of central French Polynesia and along Australia’s north Queensland coast, and at least 125% of average in Vanuatu, northern Tonga, and Pitcairn Island. Rainfall was less than 50% of average in the Northern Cook Islands and northern New Zealand.

Mean air temperatures were about 1.0 °C above average in Western Kiribati, and about 0.5 °C about average in Tuvalu, Samoa, and northern French Polynesia. In contrast, they were about 1.0 °C below average in parts of Vanuatu and southern French Polynesia, and 0.5 °C below average in New Caledonia and Fiji.

Tropical Southwest Pacific mean sealevel pressures were well above average over eastern Australia, extending towards New Zealand and further east, resulting in persistent southeasterlies over New Caledonia. Pressures tended to be below average in tropical latitudes east of the Date Line. Equatorial surface easterlies were persistent along the equator, occurring in 78% of observations at Tarawa.

Climate extremes in August 2005