Seasonal climate summary southern hemisphere (autumn 2010): rapid decay of El Niño, wetter than average in central, northern and eastern Australia and warmer than usual in the west and south

Abstract

Southern hemisphere circulation patterns and associated anomalies for the austral autumn 2010 are reviewed, with emphasis given to the Pacific Basin climate indicators together with the Australian rainfall and temperature patterns. Autumn 2010 commenced with a rapid decay of El Niño conditions in the Pacific Ocean and a transition to neutral conditions, with most indices suggesting the possibility of La Niña development in subsequent seasons. Australian rainfall was above to very much above average across much of inland Australia, with some locations observing record autumn rainfall. Drier than usual conditions were experienced in southern Tasmania, northern coastal New South Wales and pockets of the Cape York Peninsula this season, whilst the drying trend continued in Western Australia, where rainfall totals in many areas of the Pilbara and Gascoyne districts did not exceed 25 mm. Seasonal maximum temperatures were warmer than average throughout Western Australia, Victoria and Tasmania. In contrast, southern parts of the Northern Territory and Queensland experienced cooler than normal daytime temperatures. Minimum temperatures in autumn 2010 were well above the long-term average in all States and Territories, with overnight temperatures Australia-wide for April ranking as the second warmest on record. Autumn 2010 marked the end of the warmest twelve months on record for Australia following on from an extremely warm winter in 2009