 A weak low in the Timor Sea formed on 14 April, initially moving west south-west and turned southward during 16 April and 17 April.The low slowly strengthened and was named Rosita on 17 April, while located approximately to the north of Port Hedland at about 6 p.m. WST (1000 UTC).On the morning of 18 April, a ship reported a relatively high pressure of 997 hPa while passing very close to the centre of Cyclone Rosita, however, near-storm-force winds were reported.