Weekly Tropical Climate Note

Tropical low develops but monsoon not expected for northern Australia

A developing tropical low just south of Papua New Guinea has a moderate chance of reaching tropical cyclone intensity in Australia's Eastern Region later this week. Early forecasts suggest it is likely to move away from Australia as it develops further, and not directly influence the Australian mainland during its lifetime.

See the latest information and warnings for Australian tropical cyclones

The latest computer models have no indication of a monsoon trough, and potential widespread rainfall, developing near northern Australia in the coming week, despite the presence of this tropical low. However, the latest rainfall outlook issued by the Bureau indicates a high likelihood of above-average rainfall across much of Australia in the coming weeks. Other international climate outlooks do not indicate as high a likelihood of rain as the Bureau. Currently, the non-Bureau outlooks are generally indicating near-average rainfall for northern Australia in the next two to three weeks.

Madden–Julian Oscillation in Australian region forecast to weaken

A moderately strong pulse of the Madden–Julian Oscillation (MJO) is currently tracking over the western Maritime Continent, approaching Australian longitudes. The influence on rainfall patterns for tropical Australia is typically not significant in this scenario, however rainfall is usually enhanced when an MJO pulse moves into the eastern Maritime Continent. While climate models forecast the MJO pulse to move into this region in the coming days, they also forecast the strength of the MJO to weaken and become indiscernible shortly after entering the eastern Maritime Continent. In this scenario, the influence on rainfall for northern Australia could be expected to be short-lived or insignificant.

Despite the MJO contributing to the development of a monsoon trough over the Indian Ocean during the past week, it appears unlikely that development of monsoonal conditions will occur closer to Australia. There are also no indications of other atmospheric tropical waves which could influence northern Australia's weather in the coming week.

Read more about the Madden–Julian Oscillation