COLIN

History

Severe Tropical Cyclone Colin formed from a low embedded in an active monsoon trough over the north-western Coral Sea on 25 February 1976. Drifting generally southward across waters of high heat content, the disturbance organised quickly and was named Colin by the Tropical Cyclone Warning Centre in Brisbane on 26 February.

Steered by a mid-level ridge, Colin tracked south-southwestward over the following days, bringing it on a line toward the central and southern Queensland coast. It reached severe tropical cyclone status, Category 3 on the Australian scale, on 28 February, and attained its peak while positioned to the north-east of Fraser Island (K'gari), with an estimated minimum central pressure near 955 hPa. Maximum 10-minute sustained winds at peak were in the order of 140–150 km/h, with gusts over the open ocean believed to have exceeded 195 km/h.

An approaching mid-latitude upper trough then broke down the ridge to the cyclone's south, causing Colin to slow, stall and then recurve sharply to the south-east, away from the Australian mainland. Moving into higher latitudes over progressively cooler seas and encountering strong vertical wind shear, the system weakened steadily, falling below tropical cyclone intensity on 5 March and dissipating over open water by 6 March. Colin never made landfall, its destructive core remaining well offshore throughout.

Despite staying at sea, Colin's broad pressure gradient and extensive wind field drove very large swells onto the Queensland and northern New South Wales coasts, affecting the Sunshine Coast, Gold Coast and Northern Rivers districts. Significant beach erosion occurred, with localised coastal inundation around high tides, while outer rainbands delivered squally gales and heavy rain to coastal strips. High-seas warnings were maintained over Coral Sea and Tasman Sea shipping routes, and coastal shipping, fishing boats and recreational craft were confined to port for several days by dangerous surf and gale-force winds. No major structural damage was reported on land, but the hazardous seas claimed one life when a woman was swept from a cliff by a large wave.

Colin was among the stronger systems of an active 1975–76 Australian region season.

Sources: Bureau of Meteorology report Wikipedia