Powerful Tropical Cyclone Ilsa neared the coast of Western Australia on Thursday morning. At 5:00 a.m. EDT on Thursday the center of Tropical Cyclone Ilsa was located at latitude 19.1°S and longitude 119.1°E which put it about 75 miles (120 km) northwest of Pardoo Roadhouse, Australia. Ilsa was moving toward the south-southeast at 11 m.p.h. (17 km/h). The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h). The minimum surface pressure was 926 mb.

A Tropical Cyclone Warning was in effect for the coast of Western Australia from Bidyadanga to Whim Creek. The Warning included Port Hedland. The Tropical Cyclone Warning extended inland to include De Grey, Marble Bar, Nullagine, Telfer and Parnngurr.

Tropical Cyclone Ilsa continued to intensify during Wednesday night, as it moved closer to the coast of Western Australia. A very small circular eye was present at the center of Ilsa’s circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Ilsa. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the tropical cyclone. The removal of large quantities of mass was causing the surface pressure to continue to decrease.

A weather station at Bedout Island measured a sustained wind speed of 120 m.p.h. (104 kt or 193 km/h) as the core of Tropical Cyclone Ilsa was approaching it. The weather station also measured a wind gust of 144 m.p.h. (125 kt or 232 km/h).

The size of the circulation around Tropical Cyclone Ilsa increased as it intensified. Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of Tropical Cyclone Ilsa. Winds to tropical storm force extended out 140 miles (225 km) from the center. The Hurricane Intensity Index (HII) for Tropical Cyclone Ilsa was 31.6. The Hurricane Size Index (HSI) was 18.4 and the Hurricane Wind Intensity Size Index (HWISI) was 50.0. Tropical Cyclone Ilsa was similar in size and intensity to Hurricane Laura when Laura hit southwest Louisiana in 2020.

Tropical Cyclone Ilsa will move through an environment favorable for a powerful tropical cyclone during the next few hours. Ilsa will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the axis of an upper level ridge that extends from northern Australia to the South Indian Ocean. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Tropical Cyclone Ilsa is likely to maintain its intensity until it reaches the coast of Western Australia.

Tropical Cyclone Ilsa will move around the western end of a high pressure system over western Australia. The high pressure system will steer Ilsa toward the southeast during the next 24 hours. On its anticipated track, the center of Tropical Cyclone Ilsa is likely to make landfall on the coast of Western Australia near Pardoo Roadhouse in 6 hours. Ilsa will be the equivalent of a major hurricane when it makes landfall.

Tropical Cyclone Ilsa will bring very strong winds and locally heavy rain to Western Australia between De Grey and Wallal Downs. The strong winds will be capable of causing regional severe damage. Ilsa could also produce strong winds in De Grey and Telfer when it moves inland. Heavy rain could cause flash floods in some locations. Flood Warnings are in effect for the De Grey River and the Sandy Sesert. Flood Watches are in effect for the West Kimberley, Western Desert, Warburton and Salt Lake Districts. Tropical Cyclone Ilsa could also cause a storm surge of up to 10 to 15 feet (3 to 4.5 meters) along the portion of the coast near where the center makes landfall.