Severe Tropical Cyclone Laurence first developed as a tropical low in the Arafura Sea on 8 December. The low moved to the southwest passing over Darwin on 12 December causing heavy rain in excess of 100mm (Shoal Bay 163 mm) and squalls that caused some tree-related damage. The low intensified over open waters west of Darwin and was named Laurence on 13 December. Laurence reached category 3 intensity on 15 December close to the north Kimberley coast. Troughton Island recorded wind gusts to 187 km/h (101 knots) as the eye wall passed over. The small but intense cyclone then skirted the Kimberley coast reaching category 5 intensity for a brief period on the morning of 16 December before crossing the coast east of Koolan Island that evening as a category 4 cyclone with estimated gusts to 260 km/h near its centre. Laurence then moved south overland causing heavy rain as it slowed, Napier Downs (east of Derby) registering a daily fall of 402 mm to 9am 18 December. By this stage Laurence had weakened below cyclone intensity. The low subsequently tracked to the west northwest past Derby, across the Dampier peninsula and then over open waters north of Broome on 19 December where it quickly re-developed into a tropical cyclone. In the following days Laurence steadily intensified to category three on the afternoon of 20 December before turning to the south southeast towards the east Pilbara coast. Laurence eventually crossed the coast near Wallal on the 80 Mile Beach, 230 km east northeast of Port Hedland at 5pm 21 December as a category 5 cyclone with estimated wind gusts to 285 km/h near its centre. There was considerable damage to properties in the area, although fortunately there were no injuries or fatalities. The estimated number of cattle that perished was reported to be about 1500. Mandora recorded wind gusts to 211 km/h and a lowest pressure of 929 hPa. Laurence then gradually weakened over land as it moved to the southeast. Heavy rain fell in the eastern parts of the De Grey river catchment causing minor flooding, road closures but no major damage to infrastructure. Warrawagine registered 245 mm in the 24 hours to 9am on 22 December. The cyclone passed west of Telfer on 22 December before weakening over the Interior district on 23 December. Laurence was the first tropical cyclone of the Australian 2009/10 season. ***All information relating to intensity and track is preliminary information based on operational estimates and subject to change following post analysis.***
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