Unnamed system

History

Tropical Low 28U developed in the Indian Ocean approximately 450 kilometres west-southwest of Christmas Island on 1 March 2026, forming as part of an unusually active monsoon trough that simultaneously produced four tropical lows across northern Australia. Over the following days, the compact system tracked east-southeast, passing south of Christmas Island on the night of 2 March before strengthening over warm waters south of Indonesia.

The system reached peak intensity on 4 March 2026, producing a 30-hour burst of gale-force winds in its northern quadrant, with maximum sustained winds of around 75 km/h and a minimum central pressure of 990 hPa. While international agencies classified it as Tropical Cyclone 25S, the Bureau of Meteorology retained the tropical low designation because gale-force winds were not fully wrapped around its centre.

Between 5 and 6 March, 28U encountered the much larger Tropical Low 30U developing off the Western Australian coast, triggering a Fujiwhara effect in which the two systems began orbiting one another. The dominant size of 30U caused 28U to rapidly accelerate around its outer edge before wind shear and the structural interaction dismembered the smaller system. By 7 March, 28U had completely dissipated off the Kimberley coast without making landfall.

Land impacts were minimal. Christmas Island recorded 49.0 millimetres of rainfall in the 24 hours to 9:00 AM on 3 March as outer rainbands passed over the territory. No damage or casualties were reported on the Australian mainland.

Sources: Bureau of Meteorology report