 Ilsa near peak intensity while approaching Western Australia on 13 April | |
| Meteorological history | |
|---|---|
| Formed | 6 April 2023 |
| Dissipated | 15 April 2023 |
| Category 5 severe tropical cyclone | |
| 10-minute sustained (Aus) | |
| Highest winds | 230 km/h (145 mph) |
| Highest gusts | 325 km/h (200 mph) |
| Lowest pressure | 915 hPa (mbar); 27.02 inHg |
| Category 5-equivalent tropical cyclone | |
| 1-minute sustained (SSHWS/JTWC) | |
| Highest winds | 260 km/h (160 mph) |
| Lowest pressure | 919 hPa (mbar); 27.14 inHg |
| Overall effects | |
| Fatalities | 8 |
| Damage | ≥A$4 million |
| Areas affected | Maluku, Lesser Sunda Islands, Northern Territory, Western Australia |
Part of the 2022–23 Australian region cyclone season | |
Severe Tropical Cyclone Ilsa was a powerful tropical cyclone that struck Western Australia in April 2023. The sixth named storm, and the fifth severe tropical cyclone of the 2022–23 Australian region cyclone season, Ilsa formed from a tropical low off the coast of Indonesia on 6 April. It fluctuated in intensity and became a Category 1 tropical cyclone on 11 April, after deep convection became symmetric around the low-level circulation center. Ilsa then rapidly intensified the following day and reached its peak intensity as a Category 5 severe tropical cyclone on the Australian tropical cyclone intensity scale. Ten-minute sustained winds were estimated as 230 km/h (145 mph), with a central barometric pressure of 915 hPa (27.02 inHg). One-minute sustained winds reached 260 km/h (160 mph) at this time, equivalent to a Category 5 hurricane on the Saffir–Simpson hurricane wind scale. Additionally, record-breaking ten-minute sustained wind speed of 219 km/h (136 mph) were measured at Bedout Island, beating the previous record of Cyclone George in 2007. Ilsa made landfall roughly 120 km (75 mi) northeast of Port Hedland, Western Australia. Inland, Ilsa weakened to a low-end tropical cyclone with 85 km/h (50 mph) winds. Overall, Ilsa caused over A$4 million in damage, and caused 8 deaths after two boats capsized off the coast of Western Australia.