Seasonal climate summary southern hemisphere (summer 2004/05): a neutral ENSO situation with a cooling Pacific. Hot and dry over the western half of Australia

Southern hemisphere circulation patterns and associated anomalies for the austral summer 2004/05 are reviewed, with emphasis given to the Pacific Basin climate indicators and Australian rainfall and temperature patterns. Neutral ENSO conditions persisted during the summer of 2004/05. Near-equatorial Pacific surface temperatures were generally warmer than average, but most anomalies decreased by around 0.4 degree C during the course of the season. February was a particularly anomalous month; it was characterised by a large fall in the Southern Oscillation Index, strongly enhanced convection around the date-line, strong westerly wind anomalies in the western to central tropical Pacific and numerous tropical cyclones over the central Pacific. Australian summer rainfall totals were well below average in a band extending from northwest WA to the far western border areas of NSW and Queensland. It was also much hotter than average over the western half of the country, particularly in the Pilbara of WA where mean maximum and minimum temperatures were the highest on record.