Cyclone Tracy

Cyclone Tracy was a tropical cyclone that devastated Darwin, Australia, from December 24 to December 25, 1974. It was recorded by The Age as being a "disaster of the first magnitude...without parallel in Australia's history." It killed 65 people and destroyed over 70 percent of Darwin's buildings, leaving over 20,000 people homeless. Most of Darwin's population was evacuated to Adelaide, Whyalla, Alice Springs and Sydney, and many never returned to Darwin. The town was subsequently rebuilt with modern materials and techniques. Cyclone Tracy was at least a Category 4 storm, although there is evidence to suggest that it had reached Category 5 when it made landfall at Darwin.

The storm

On 20 December, 1974, the U.S. Environmental Satellite ESSA-8 recorded a large cloud mass centered in the Arafura Sea about 370 km north-east of Darwin. This was tracked by the Darwin Weather Bureau's regional director Ray Wilkie and senior meteorologist Geoff Crane. On December 21 1974, ESSA-8 showed evidence of a newly formed circular centre near latitude 9 degrees south and longitude 132 degrees east. The meteorological duty officer at the time, Geoff Crane, issued an initial tropical cyclone alert describing the storm as a tropical low that could develop into a tropical cyclone.

Related Topics:
20 December - 1974 - U.S. - Environmental Satellite - ESSA-8 - Arafura Sea - Meteorologist - December 21 - Latitude - Longitude

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Later in the evening, the Darwin meteorological office received an infrared satellite image from United States NOAA satellite NOAA-4 showing low pressure had developed further and spiralling clouds could be seen. http://www.library.bom.gov.au/dbtw-wpd/exec/dbtwpcgi.exe?AC=GET_RECORD&XC=/dbtw-wpd/exec/dbtwpcgi.exe&BU=http%3A%2F%2Fwww.library.bom.gov.au%2Fqmetext.htm&TN=METEORIC&SN=AUTO6373&SE=164&RN=28&MR=50&TR=0&TX=1000&ES=0&CS=1&XP=&RF=Summary&DF=DisplayOPAC&RL=0&DL=0&NP=2&ID=&MF=&MQ=&TI=0&DT= The storm was officially pronounced a tropical cyclone at around 10 PM on December 21, when it was around 700 km northeast of Darwin. Over the next few days it moved in a south-west direction, passing north of Darwin on December 22. A broadcast on ABC Radio that day stated that Cyclone Tracy posed no immediate threat to Darwin. However, early in the morning of December 24, Tracy rounded Cape Fourcroy (the western tip of Bathurst Island) and moved in a south-easterly direction, straight towards Darwin.

Related Topics:
NOAA - NOAA-4 - December 21 - December 22 - ABC Radio - December 24 - Cape Fourcroy - Bathurst Island

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

By late afternoon, the city was heavily overcast with low clouds and was experiencing strong rain. Wind gusts appeared and were starting to cause physical damage. Between 10 PM and midnight, the damage became serious, and the cyclone's effect became imminent to the residents. After midnight, the cyclone passed directly over Darwin, with its 'eye' centred on the airport and northern suburbs. The wind gauge at Darwin Airport officially recorded winds of 217 kilometres per hour (135 mph) before being blown away itself. Unofficial estimates suggested that the wind speed had reached 300 kilometres per hour (185 mph). The winds and torrential rain continued until dawn. By 6 AM, Tracy had killed 65 people—49 on land and 16 at sea—and Darwin had been substantially destroyed.

Related Topics:
Overcast - Wind speed

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Due to the destruction of infrastructure, the distance between Darwin and the rest of the Australian population and the fact it was Christmas Day and most media outlets had only a skeleton crew rostered on at best, the news of the cyclone took some time to reach people. Most Australians were not aware of the cyclone until late in the afternoon.

Related Topics:
Infrastructure - Australian population

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The initial emergency response was from a leadership committee of high-level public servants and police which stated that, "Darwin had, for the time being, ceased to exist as a city". Gough Whitlam, then Australian Prime Minister, was touring Syracuse at the time but flew to Darwin on hearing of the disaster. The Government began a mass evacuation by road and air. All Defence Force personnel throughout Australia were recalled from holiday leave, and the entire Royal Australian Air Force fleet of transport planes were deployed to evacuate civilians from the city and to bring essential supplies.

Related Topics:
Gough Whitlam - Royal Australian Air Force

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Tracy was the most compact tropical cyclone on record, with gale-force winds extending only 48 km (30 miles) from the centre.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~