Cyclone Justin - Meteorological History

Meteorological History

Cyclone Justin was the largest tropical cyclone to hit Northern Queensland in 1997. On 7 March, over the Coral Sea, Cyclone Justin began to form. The way in which it formed was as follows. The sea waters were at least 27 °C, and as a result some of this water was evaporated into the air. This water vapour then rose upwards and created large cumulonimbus clouds. These clouds grouped together and caused a current of warm, moist, rapidly rising air to occur. As a result of this current a low-pressure area on the surface of the sea began to develop. This low-pressure area made the trade winds (In the southern hemisphere, where Cyclone Justin formed, they are the east to south-easterly winds) to become much stronger, and indeed, allowed them to impart enough force to rotate the cumulonimbus clouds. As these winds spiralled around the low-pressure area (the ‘eye’) they released heat and moisture which supplied the now cyclone with energy.

It spent the first week of its life following an erratic path around the Coral Sea; however, with the constant cloud cover the water temperature dropped 4 °C. As a consequence of this, Cyclone Justin was deprived of its vital energy source (the warm water vapour) and therefore moved northeast, towards Papua New Guinea to warmer water. Here, it grew to a Category 3 cyclone and caused storm force winds and storm surges. On 22 March it retreated to Queensland where it made landfall, as a Category 2 cyclone, north of Cairns.

The areas in and around Cairns, Innisfail and Mareeba areas were devastated with large storm surges, excessive flooding, gusts of winds which reached up to 130 km/h and landslides.