Monthly climate

Enhanced convection persists in teh central equatorial Pacific

A large area of very enhanced convection, although less extensive than in August, persisted in the central equatorial Pacific during September. This was assisted by anomalous surface equatorial westerlies between 160°E and 180°E (occurring in 80% of observations at Tarawa, Western Kiribati; the highest frequency there since the middle of the last El Niño in October 1997). This convergence affected much of the region between 5°N and 5°S and 165°E and 165°W,enhancing rainfall from Nauru, across to Eastern Kiribati. Very anomalous September rainfall, more than 1000% of average was recorded in parts of Eastern Kiribati, and totals were at least 200% of average throughout much of Western Kiribati, as well as localised parts of Vanuatu, Tonga and the Marquesas Islands. Rainfall was at least 125% of average over much of Fiji. Tarawa has recorded 854 mm in the past two months.

The SPCZ was near its average location about and west of the date line, between the Solomon Islands and Tuvalu. However, it continued to be weak with little activity further east in the Southwest Pacific.

Convection was suppressed, with sunny conditions, over Indonesia, and extending to Papua New Guinea. Dry conditions extended from Australia across the Coral Sea to New Caledonia, with rainfall less than 50% of average in many areas. Rainfall was also below average from the Niue across to central French Polynesia.

Some new temperature extremes were recorded in Fiji and French Polynesia.

Climate extremes in September 2002