The 1999–2000 Australian region cyclone season was a slightly above average tropical cyclone season. It ran from 1 November 1999 to 30 April 2000. The regional tropical cyclone operational plan also defines a "tropical cyclone year" separately from a "tropical cyclone season", with the "tropical cyclone year" for this season lasting from 1 July 1999 to 30 June 2000. Two of the most notable cyclones of the season were Steve and Rosita. Cyclone Steve transversed the entire Australian continent, and although a fairly weak cyclone, caused widespread flooding in Queensland, Northern Territory and Western Australia, while Cyclone Rosita made an almost direct hit on Broome as a severe Category 4 cyclone, devastating several remote stations and the town itself. Rosita surprised many residents of its arrival, as it made landfall very late in the season. Systems Tropical Cyclone Ilsa Ilsa formed to the northeast of the Cocos Islands on 11 December 1999. The cyclone moved to the south of Christmas Island on the 13th producing a heavy swell which caused some damage. Its development was impeded by vertical windshear for a large part of its lifetime. After a long track eastwards across the Indian Ocean it eventually crossed the Western Australian coastline on the Eighty Mile Beach near the Sandfire Roadhouse during the early afternoon of 17 December 1999. Apart from producing heavy rainfall, Ilsa did not produce any significant damage. Severe Tropical Cyclone John Tropical Cyclone John started as a low to the south-west of Timor on 9 December 1999. It rapidly intensified and moved towards the Pilbara coast of Western Australia. Just before landfall it was a severe category 5 storm with a central pressure of 915 hPa, with winds estimated at being up to . The cyclone crossed the coast just to the west of Whim Creek between Port Hedland and Karratha on 8:30 am (WST) 15 December 1999. At the time of coastal crossing, it was estimated to have a central pressure between 930 and 940 hPa. The cyclone moved inland before dissipating the next day. Port Hedland experienced gale-force winds for a period of 18 hours and near storm force winds with gusts to were observed on 15 December for most of the day. A maximum storm surge of 2 metres was recorded by the Port Hedland Authority at 6 am WST. At Karratha, on the western side of the circulation, the maximum wind gust