In the tropical Pacific, abnormally warm sea-surface temperatures off the South American coast were the main feature of the season. The warm waters were accompanied by anomalously strong westerlies in the western central Pacific, and re-strengthened atmospheric convection in the tropical central Pacific. Widespread excessive rainfall covered most parts of the Australian continent and caused generally lower maximum and minimum temperatures, especially in December and February.
Zhenjie Lin (Wed,) studied this question.