Climate outlook for September to November

Issued 28 August 2014

Climate outlook overview

A drier than normal September to November is more likely for parts of the southeast mainland. Elsewhere, the chances of a wetter or drier than normal September to November are roughly equal.
The September outlook suggests drier conditions are more likely for many parts of southern Australia in early spring.
Southern Australia and parts of the northern tropics are more likely to see warmer than usual days.
Warmer than average nights are more likely for the southern half of Australia and the northern Cape York Peninsula in Queensland.
Climate influences include a weakening negative Indian Ocean Dipole, and near-average to warm temperatures in the tropical Pacific Ocean.

A drier than normal September to November is more likely for central Victoria and southern and central NSW, though early spring (September) is more likely to be drier than normal over a large part of southern Australia.
For the remainder of Australia, the chances of a wetter or drier than usual September to November are roughly equal.
Climate influences include a weakening negative Indian Ocean Dipole, and near-average to warm temperatures in the tropical Pacific Ocean.
Outlook accuracy for the season is moderate to high over most of the eastern States and the NT.

Warmer than normal September to November days are more likely for southern Australia and the northern tropics, with the strongest odds in the southeast early in the season.
Warmer than normal nights are also likely for the southern half of the country, while the Kimberley coastline of WA is more likely to experience cooler than normal nights.
Climate influences include a weakening negative Indian Ocean Dipole, and near-average to warm temperatures in the tropical Pacific Ocean.
Maximum temperature accuracy is moderate to high over most of Australia, although lower over some parts of WA. Minimum temperature accuracy is moderate over most of central and southeast Australia, and patchy through WA, parts of the NT and Queensland.

Currently, tropical Pacific Ocean temperatures remain within neutral levels. POAMA, the Bureau's seasonal outlook model, expects the tropical Pacific to warm slightly, but remain within the neutral range for the remainder of the year. Approximately half of the international climate models still suggest El Niño is likely. The spring rainfall outlook for the country reflects this forecast, with a weak drier signal across the southeast of the country, and warmer daytime temperatures.
The Indian Ocean Dipole (IOD) index has been below −0.4 °C (the negative IOD threshold) since mid-June. 2014 is now considered a negative IOD year. Model outlooks suggest the IOD is likely to be relatively short lived, with the Indian Ocean returning to neutral in early spring. A negative IOD typically brings wetter winter and spring conditions to inland and southern Australia. However, given its short life expectancy, the negative IOD is unlikely to be affecting the seasonal outlook.
Bureau climatologists continually monitor the climate for any significant developments, with information on the likelihood of El Niño/La Niña and IOD events available fortnightly at the ENSO Wrap-Up. For a summary of Pacific and Indian Ocean outlooks, please see the Climate Model Summary.