Tropical Climate Update

Two tropical cyclones over northern Australia

During the past week, two tropical systems were active over the north of the continent. Tropical cyclone Blake formed off the Kimberley coast of Western Australia on Monday 6 January. Blake was a weak system, peaking at category 1 intensity, and made landfall along the northern WA coast during the evening of 7 January. It subsequently tracked across parts of inland WA, generating localised heavy rainfall.

Severe tropical cyclone Claudia remains active off the northern WA coast. Claudia has maintained its maximum intensity of category 3, making it the first severe tropical cyclone for Australia in the 2019–20 season, though forecasts indicate it will weaken in the next 12–24 hours. While Claudia is not expected to have any further direct impact on the Australian mainland, in its pre-tropical cyclone phase, the system generated very heavy rainfall in parts of the Northern Territory as it tracked westwards across the Arafura Sea. Dum In Mirrie and Wagait Beach, in the northwestern Top End of the Northern Territory, both recorded daily falls in excess of 500 mm in the 24 hours to 11 January. The rainfall of 562.0 mm at Dum In Mirrie was the highest daily total ever recorded in the NT.

Tropical cyclone information for Australia is available on the Bureau's Current Tropical Cyclones page

Widespread rainfall expected over parts of northern Australia

A monsoon trough which provided ideal conditions for Blake and Claudia to form off the northern Australia coast has moved offshore. As a result, monsoonal conditions are no longer occurring across northern Australia, although significant residual moisture remains over the region. This increases the likelihood of widespread rainfall over parts of the northwest of the country and northern Queensland in the coming week. Meanwhile, a monsoon trough and associated tropical low is establishing over the northern Coral Sea, east of the northern Queensland coast. As a result, the risk of tropical cyclone formation over waters to the north of Australia has reduced.

While monsoon-like conditions were experienced over northern Australia this past week, and some locations experienced heavy rainfall, official thresholds used to determine the monsoon onset at Darwin were not met. Monsoonal flow was too shallow and did not last long enough over Darwin for monsoon criteria to be met.

Strong Madden–Julian Oscillation moves east of Australian region

A very strong pulse of the Madden–Julian Oscillation (MJO) recently moved into the eastern Maritime Continent, to Australia's northeast. The rapidly moving MJO, and other tropical atmospheric waves have contributed to a shift of the most active tropical weather from northern Australia, further east into the northern Coral Sea. The MJO is forecast to rapidly track further east into the tropical southwest Pacific in the coming week, and so the strongly enhanced cloudiness and rainfall over northern Australia is expected to steadily reduce from next week.

Read more about the Madden–Julian Oscillation