GLORIA

History

Tropical Cyclone Gloria developed in mid-January 1975 from a low embedded in an active monsoon trough over the eastern Indian Ocean, roughly 400 km north-northwest of Port Hedland. The system consolidated quickly, and the Tropical Cyclone Warning Centre in Perth named it Gloria on 15 January as it drifted west-southwestward across warm waters off the north-west Australian coast.

A ridge of high pressure over the Australian continent steered Gloria on a steady west-southwesterly course that ran roughly parallel to the Pilbara coastline, keeping the cyclone offshore throughout its life. Intensification was rapid, and by 17 January Gloria had strengthened to Category 3 on the Australian scale, becoming a severe tropical cyclone. At its peak the central pressure fell to about 960 hPa, with maximum sustained winds estimated near 130–140 km/h and gusts over open water exceeding 180 km/h. Peak intensity occurred while the system was positioned well seaward of North West Cape.

As Gloria continued westward away from the mainland and into the central Indian Ocean, conditions turned hostile. Strong vertical wind shear and the entrainment of dry air disrupted the circulation, and the cyclone fell below tropical cyclone strength late on 18 January before dissipating over open water on 19 January. Some records place the system's broader life cycle as extending from 14 to 23 January.

Because Gloria never approached the coast, impacts on land were negligible. No gale-force winds or heavy rainfall affected settlements along the Pilbara or Gascoyne coasts, and no structural damage, injuries or deaths were attributed to the system. Its main operational consequence was at sea, where marine storm warnings were issued for North West Shelf shipping lanes; commercial vessels and offshore oil exploration platforms activated heavy weather procedures, and no damage was reported.

Gloria was one of a number of systems in an unusually active and destructive 1974–75 Australian region season, which also produced Cyclone Tracy.

Sources: Bureau of Meteorology report Wikipedia