The South Pacific and southeast Indian Ocean tropical cyclone season 2004-05

Eighteen tropical cyclones formed in the combined southeast Indian Ocean and South Pacific Ocean basins during the 2004-05 season and they all, with the exception of the short-lived September cyclone Phoebe, developed between December and April. Four intense tropical cyclones developed east of 180°E in the South Pacific region during February and significantly affected South Seas islands from Tokelau in the north to Rarotonga in the south. Other cyclones/depressions impacted on the Port Moresby area of Papua New Guinea and across much of Northern Australia. Weakly negative to neutral ENSO conditions prevailed and mostly positive sea-surface temperature (SST) anomalies were observed over the region throughout the season. The genesis area for the four severe tropical cyclones, in the area to the east of 180°E, was also closely aligned with the most vigorous arm of the Hadley circulation in the western Pacific.