SELWYN

History

Tropical Cyclone Selwyn was a modest, entirely offshore system that developed over the eastern Indian Ocean during late February 1986. Its precursor tropical low was first identified along an active monsoon trough on 20 February, some 600 km north-northwest of Broome. Drifting slowly towards the west-southwest across warm waters, the disturbance became progressively better organised over the following two days as its central pressure fell.

By 23 February the low had generated gale-force winds, prompting the Bureau of Meteorology's Tropical Cyclone Warning Centre in Perth to name it Selwyn as a Category 1 system. Steered along the northern flank of a mid-level ridge positioned to its south, the cyclone maintained a southwesterly heading and strengthened further, reaching Category 2 on the Australian scale late on 23 February. Selwyn attained its greatest intensity on 24 February near 16.0°S, 114.5°E, with an estimated minimum central pressure of about 980 hPa, maximum 10-minute sustained winds of roughly 95–100 km/h (50–55 knots) and gusts to around 135 km/h.

The cyclone's peak was short-lived. An upper-level westerly trough moved into the region on 25 February, introducing strong vertical wind shear that tore the deep convection away from the circulation centre and left the low-level vortex exposed. Selwyn was downgraded to a tropical low late that day and dissipated over open water on 26 February, roughly 500 km northwest of North West Cape.

Selwyn never approached the Australian coast and produced no direct weather impacts on the Kimberley or Pilbara. Marine gale warnings were issued for shipping lanes across the North West Shelf, but offshore oil and gas platforms reported no structural damage or meaningful disruption to operations. No deaths, injuries or property damage were attributed to the system, one of a number of cyclones in an above-average 1985–86 Australian region season.

Sources: Bureau of Meteorology report Wikipedia