The lowest air pressure reading during Tracy was 950 hectopascals (28.05 inHg), which was taken at around 4 a.m., by a Bureau staff member at Darwin Airport. The Bureau of Meteorology's official estimates suggested that Tracy's gusts had reached 240 kilometres per hour (150 mph). The anemometer (wind speed instrument) failed at around 3:10 a.m., with the wind vane (wind direction) destroyed after the cyclone's eye passed over. The highest recorded wind gust from the cyclone was 217 kilometres per hour (135 mph), which was recorded around 3:05 a.m. On 25 December at around 3:30 a.m., Tracy's centre crossed the coast near Fannie Bay. (local time) and midnight, the damage became serious, and residents began to realise that the cyclone would not just pass by the city, but rather over it. Wind gusts increased in strength between 10 p.m. īy late afternoon on 24 December, the sky over the city was heavily overcast, with low clouds, and was experiencing strong rain. The bureau's weather station at Cape Fourcroy measured a mean wind speed of 120 km/h (75 mph) at 9:00 that morning. However, early in the morning of 24 December, Tracy rounded Cape Fourcroy on the western tip of Bathurst Island, and moved in a southeasterly direction, straight towards Darwin. A broadcast on ABC Radio that day stated that Cyclone Tracy posed no immediate threat to Darwin. Over the next few days, the cyclone moved in a southwesterly direction, passing north of Darwin on 22 December. Cyclone Tracy was first observed on the Darwin radar on the morning of 22 December. on 21 December, when it was around 200 km (125 mi) to the north-northeast of Cape Don (360 km (225 mi) northeast of Darwin). The storm was officially pronounced a tropical cyclone at around 10 p.m. Later in the evening, the Darwin meteorological office received an infrared satellite image from the National Oceanic and Atmospheric Administration's satellite, NOAA-4, showing that the low pressure had developed further and that spiralling clouds could be observed. Crane - the meteorological duty officer at the time - issued the initial tropical cyclone alert, describing the storm as a tropical low that could develop into a tropical cyclone. On 21 December 1974, the ESSA-8 satellite showed evidence of a newly formed circular centre near latitude 8° south and longitude 135° east. This disturbance was tracked by the Darwin Weather Bureau's regional director Ray Wilkie, and by senior meteorologist Geoff Crane. On 20 December 1974, the United States' ESSA-8 environmental satellite recorded a large cloud mass centred over the Arafura Sea about 370 km (230 mi) northeast of Darwin. Meteorological history Įxtratropical cyclone, remnant low, tropical disturbance, or monsoon depression The storm is the second-smallest tropical cyclone on record (in terms of gale-force wind diameter), behind only Tropical Storm Marco in 2008. After the storm passed, the city was rebuilt using more stringent standards "to cyclone code". It left more than 25,000 out of the 47,000 inhabitants of the city homeless prior to landfall and required the evacuation of over 30,000 people, of whom many never returned. It destroyed more than 70 percent of Darwin's buildings, including 80 percent of houses. Tracy killed 71 people, caused A$837 million in damage (1974 dollars), or approximately A$7.2 billion (2022 dollars), or US$5.2 billion (2022 dollars). Additionally, news outlets had only a skeleton crew on duty over the holiday. Residents of Darwin were celebrating Christmas, and did not immediately acknowledge the emergency, partly because they had been alerted to an earlier cyclone ( Selma) that passed west of the city, and did not affect it in any way. The anemometer in Darwin Airport control tower had its needle bent in half by the strength of the gusts. ACST, damage became severe, and wind gusts reached 217 kilometres per hour (134.84 mph) before instruments failed. The small, developing easterly storm had initially appeared likely to pass clear of the city, but then turned towards it early on 24 December. Part of the 1974–75 Australian region cyclone seasonĬyclone Tracy was a tropical cyclone that devastated the city of Darwin, Northern Territory, Australia, from 24 to 26 December 1974.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |