Summer 2007–08

A positive SAM event coincided with a late-developing La Niña that peaked in late summer. Lower than average pressure over Antarctica and the Southern Ocean was surrounded by higher than average pressure across the southern parts of the Pacific, Indian and Atlantic oceans (see image).

Australian rainfall deciles for summer 2007–08 — Mean sea level pressure anomaly chart for summer 2007–08 for the southern hemisphere. Base period is 1979–2000. Lower than average pressure is evident near Antarctica (as indicated by the purple and blue colours) and higher than average pressure is located over parts of the southern Indian Ocean, the south Atlantic Ocean the southern Pacific Ocean (as indicated by the yellows and reds). This pattern is common during a positive SAM event. *Data: ERA Interim*.

Both the positive SAM and La Niña contributed to the above average rainfall recorded over most of eastern Australia, including large parts of New South Wales and southern Queensland. This is a typical response during summers influenced by positive SAM. At the time, it was the eighth-wettest summer on record for Queensland and the tenth-wettest for New South Wales. Almost a dozen New South Wales stations recorded their wettest summer on record along with a handful of Queensland stations.