[1][2] Ten months after the storm's passage, the skull of an 81-year-old man, who was believed to have been swept away by flood waters, was discovered.

The cyclone attained a minimum central pressure of 920 hPa, and maximum wind gusts of 320 km/h (200 mph) at 8 p.m. CST (1030 UTC) on the 8 December, only two days after being named.

[4][5] Thelma continued moving steadily southwest at about 10 km/h (6.2 mph) before turning southwards, passing about 50 km (31 mi) from Troughton Island.

The cyclone weakened to a Category 3 while crossing the Kimberley coast northwest of Kuri Bay early on 11 December.

On the morning of 14 December, the low crossed the Pilbara coast north of Wallal, 240 km (150 mi) east northeast of Port Hedland.

[4][5] All residents of major communities, including Darwin, and offshore installations directly affected by the cyclone were either evacuated or were sheltered in secure accommodation.

The radio and television reception was interrupted by heavy rain and lightning, and the power supply in Pirlangimpi (Garden Point) was cut by fallen trees.

[6] In the Kimberley region, there was minor damage to some buildings at Kalumburu and water level in the river rose to within 50 metres (160 feet) of the town.

The BHP facilities at Troughton Island were affected by very destructive winds and heavy rainfall from the cyclone's core, damaging the runway and buildings.