Weekly Tropical Climate Note
Tropical cyclone activity in Australian Region
During the past week, 2 tropical cyclones developed over Australian waters. Tropical cyclone Joshua developed over the Indian Ocean, well away from the Western Australia coast. It tracked westwards out of the Australian Region as a category 1 system, not affecting any significant land masses.
Tropical cyclone (TC) Kimi developed very close to the north Queensland coast, east of Cairns. Kimi was a small, compact system which tracked in a southerly direction and intensified to category 2 strength. Environmental conditions during Monday 18 January became unfavourable, leading to rapid weakening and downgrading of Kimi to a tropical low. Ex-TC Kimi is no longer expected to produce damaging winds, but may generate heavy rainfall along parts of Queensland's north tropical coast in the coming days.
A separate tropical low over the Timor Sea, northwest of Darwin, has been assessed as having a high chance of becoming a tropical cyclone in the next few days. If this low develops to tropical cyclone intensity, it is likely to track south-westwards towards the Kimberley or Pilbara coasts of Western Australia.
Madden–Julian Oscillation moves into Australian area
The Madden–Julian Oscillation (MJO) tracked eastwards into the Maritime Continent, north of Australia, in recent days. This pulse of the MJO is moderately strong, although climate models predict it will weaken as it moves further east in the coming week.
Combined with another type of tropical atmospheric wave, an equatorial Rossby wave, the MJO is likely to maintain conditions favourable for the current burst of monsoon activity across northern Australia. The monsoon conditions will likely see enhanced tropical convection and above-average rainfall continue across parts of northern Australia in the coming fortnight.
Read more about the Madden–Julian Oscillation
Monsoon conditions to continue across Australia
The presence of the MJO, along with an equatorial Rossby wave, contributed to the development of active monsoon conditions across northern Australia. A monsoon trough currently extends from waters north of the Northern Territory to the eastern Indian Ocean.
The active monsoon is expected to influence much of tropical Australia in the coming fortnight, contributing to widespread heavy rainfall. Some models predict the MJO may move rapidly out of the Australian region and into the western Pacific region. In this scenario, parts of northern Australia, particularly more westerly locations, could see a decrease in tropical convection in about a week. Eastern parts of tropical Australia, the Coral Sea and the eastern Maritime Continent typically experience above-average rainfall with an MJO pulse over the western Pacific.
However, most guidance indicates monsoon conditions will persist over the entire region, increasing the likelihood of above-average cloudiness and rainfall for much of northern Australia during the next fortnight. During this period, there is an increased risk of tropical low and cyclone formation over Australian waters.
Product code: IDCKGEW000
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