Severe Tropical Cyclone Gwenda is tied with Cyclone Inigo as the most intense Australian tropical cyclone on record (with the possible exception of Cyclone Mahina), with a barometric pressure of 900 hPa (mbar) and was the most intense storm worldwide in 1999. Forming out of a tropical disturbance over the Arafura Sea on 2 April 1999, the precursor to Gwenda tracked slowly westward and gradually became more organised. On 4 April, the system developed into a Category 1 cyclone and was named Gwenda. It began to undergo explosive intensification the following day, and in a 30-hour span ending early on 7 April, the storm's maximum 10-minute sustained wind speed increased from to and its barometric pressure decreased to 900 hPa (mbar). The Joint Typhoon Warning Center reported that the storm had peaked as a high-end Category 4 equivalent on the Saffir–Simpson hurricane scale. Increasing wind shear and an acceleration in forward speed caused Gwenda to quickly weaken. Less than 18 hours after peaking, the storm made landfall roughly east of Port Hedland, Western Australia with winds of . After moving ashore, Gwenda abruptly stalled before dissipating on 8 April. Although it was once an extremely intense cyclone, the factors that caused its deterioration also prevented significant damage. Rainfall from the storm peaked at . Minor structural damage was reported, and only localised flooding was recorded. Following its usage, the name Gwenda was retired at the end of the season. Meteorological history Severe Tropical Cyclone Gwenda originated from a weak tropical disturbance that formed on 1 April over the Arafura Sea. Drifting westward, the system gradually became better organised, and early on 2 April, the Australian Bureau of Meteorology classified it as a tropical low. Over the following two days, the low continued to mature; on 4 April, the Bureau of Meteorology upgraded it to a Category 1 cyclone and named it Gwenda. Around the same time, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert as deep convection became concentrated around the centre of circulation and the system's outflow significantly improved. Located within an environment of low to moderate wind shear, the storm was expected to intensify. By 5 April, the JTWC began issuing advisories on Gwenda, classifying it as a weak tropical storm and designating it as Cyclone 32S. Tracking southwest in response to a subtropical ridge to the south, Gwenda began to rapidly intensify. Its