A tropical low formed in the Coral Sea east of Lockhart River on the March 4th 2009. The low drifted to the southwest and intensified to become Tropical Cyclone Hamish on the March 5th. It continued in a south to southwest direction and intensified over the following 24 hours, before taking a south-south-easterly track parallel to the coast. Severe Tropical Cyclone Hamish reached category 3 intensity on the March 6th and, in conditions favourable for further development, intensified to category 5 on March 7th. Hamish continued its southeast track parallel to the coast and maintained category 4 intensity or higher for the following few days. Eventually it moved into a region of increasing wind shear, and by the March 10th the system became sheared with the upper circulation captured by strong upper winds. The low level circulation then moved back to the north and northwest while weakening to below tropical cyclone intensity in the early hours of March 12th.
Hamish passed close to a number of Automatic Weather Stations in the Coral Sea, which provided valuable data on the system. Gannet Cay recorded a pressure of 949.2 hPa and a wind gust of 190 km/h, prior the anemometer failing on the morning of March 9th. A wind gust of 219 km/h was recorded at Flinders Reef at 3pm March 7th.
Severe Tropical Cyclone Hamish threatened to track near a number of offshore Islands, with associated damaging winds, large waves and elevated sea levels. Evacuations of the Whitsunday group of Islands, Heron, Lady Elliott and Fraser Island were organised prior to the potential impact of the system.
A fishing trawler capsized in the Swains Reef area as Hamish passed nearby. One of the 3 crew was rescued, but two remained missing. A bulk carrier off Stradbroke Island lost its cargo of containers in large waves, and oil leaked from its ruptured fuel tanks left an oil slick on Southeast Queensland beaches from the Sunshine Coast to Bribie and Moreton Islands. Dangerous surf conditions also affected southeast Queensland beaches.