User:ChocolateTrain/Cyclone Damien (2020)

Severe Tropical Cyclone Damien was a strong tropical cyclone that brought significant impacts to Western Australia during February 2020. It was the fifth tropical low, third tropical cyclone, second severe tropical cyclone and most intense tropical cyclone of the 2019–20 Australian region cyclone season. It was also the strongest system to make landfall in mainland Western Australia since Severe Tropical Cyclone Christine in December 2013. Damien began as a weak inland tropical low that formed within a monsoon trough over the Northern Territory on 2 February. Over the following days, the tropical low tracked westwards with little development, before emerging over the eastern Indian Ocean on 5 February. Once over water, the system began to intensify steadily in a highly favourable environment. The tropical low strengthened into a tropical cyclone at 06:00 UTC on 6 February, and was named Damien by the Australian Bureau of Meteorology (BOM). Damien became a Category 3 severe tropical cyclone less than 24 hours later, and continued to intensify while turning southwards towards the Pilbara coast of Western Australia. Damien made landfall in the small town of Dampier at 07:30 UTC on 8 February at peak intensity, with estimated 10-minute sustained winds of 155 km/h (100 mph) and gusts to 220 km/h (140 mph).

Meteorological history
On 2 February 2020, the Australian Bureau of Meteorology (BOM) noted that a monsoon trough had begun to develop over the Northern Territory. A weak inland tropical low had also formed within this developing monsoon trough, centred over the Tanami district of the Northern Territory, approximately 700 km (430 mi) south of Darwin. Under the steering influence of a high-pressure ridge to the south, the tropical low proceeded to track steadily westwards over the Kimberley region of Western Australia for the next several days. The system emerged over the eastern Indian Ocean near Cape Leveque just before 12:00 UTC on 5 February, and immediately began to display signs of organisation. Very warm sea surface temperatures in excess of 30 °C (86 °F), strong upper-level outflow and low vertical wind shear allowed deep convection to quickly develop and organise over the tropical low. As the convective structure improved, the Joint Typhoon Warning Center (JTWC) upgraded the system to a tropical storm on the Saffir-Simpson hurricane wind scale (SSHWS) at 00:00 UTC on 6 February. The BOM followed suit six hours later, officially upgrading the system to a Category 1 tropical cyclone on the Australian scale, and naming it Damien.

The atmospheric environment continued to improve throughout the day, with a low-pressure trough approaching from the southwest strengthening divergence in the upper troposphere and aiding the establishment of poleward and equatorward outflow channels. Atmospheric analysis indicated that vertical wind shear had also weakened further. Damien strengthened quickly in the favourable conditions, and was upgraded to Category 2 on the Australian scale by the BOM at 21:00 UTC. At this time, the mid-level ridge that had been steering Damien towards the west began to recede eastwards due to the approaching trough, causing the cyclone to start a steady southwards turn. Rapid intensification continued, and Damien became a Category 3 severe tropical cyclone on the Australian scale at 09:00 UTC on 7 February. The JTWC also indicated around this time that Damien had strengthened into a Category 1-equivalent hurricane on the SSHWS. An 11 km (7 mi) diameter eye emerged in enhanced infrared satellite imagery at 10:20 UTC as deep convection started to wrap around the centre of the system. The eye expanded and became more ragged in the ensuing hours; however, the JTWC indicated that intensification had continued, and Damien was upgraded to Category 2 on the SSHWS at 18:00 UTC. Six hours later, however, Damien began to weaken slightly as a result of a diminishing equatorward outflow channel and an increase in vertical wind shear. The weakening phase proved short-lived, however, and a combination of high ocean heat content and the otherwise favourable atmospheric environment allowed the system to intensify until making landfall at Dampier at approximately 07:30 UTC on 8 February. At the time of landfall, Damien was a maximal Category 3 severe tropical cyclone on the Australian scale with estimated maximum 10-minute sustained winds of 155 km/h (100 mph), gusting to 220 km/h (140 mph), and a minimum barometric pressure of 955 hPa (28.20 inHg). The JTWC analysed Damien at maximal Category 2 intensity on the SSHWS, with one-minute sustained winds of 175 km/h (110 mph).

As Damien began to track inland over the desert of Western Australia's Pilbara region, the system began to display evidence of weakening, including an increasingly ragged eye structure. Despite tracking over land, the rate of weakening was tempered somewhat by the system's robust poleward outflow channel being enhanced by the upper trough to the south. Damien weakened to Category 2 intensity on the Australian scale at 15:00 UTC, and further to Category 1 at 00:00 UTC on 9 February while passing about 30 km (20 mi) west-northwest of the town of Tom Price. Deep convection remained persistent near Damien's centre of circulation; however, land interaction and the influence of moderate northerly wind shear continued to degrade the system. After tracking approximately 320 km (200 mi) inland, Damien was downgraded to a tropical low by the BOM at 06:00 UTC while located about 35 km (20 mi) to the south-southwest of Paraburdoo. The BOM noted that despite being classified as a tropical low, sustained gale-force winds could persist in the southwestern quadrant of the system for the following few hours. The system was downgraded below tropical storm status on the SSHWS at 00:00 UTC on 10 February. Ex-Tropical Cyclone Damien tracked in a general south-southeasterly direction across inland Western Australia before dissipating as a tropical system over the northern Goldfields by 06:00 UTC on 11 February.

Damien was the strongest tropical cyclone to make landfall in mainland Western Australia since Severe Tropical Cyclone Christine in December 2013. Damien also produced the strongest winds observed in the Dampier–Karratha area since Severe Tropical Cyclone Orson made landfall in April 1989.

Preparations
In preparation for the arrival of Cyclone Damien, all 22 public and private schools in the Pilbara region were closed on 7 February. Several schools in the worst-affected areas also remained closed through 11 February. Numerous flights in the region were cancelled as a precaution, with regional airline Aviair cancelling all services from Port Hedland to Karratha and Newman. The port of Port Hedland, one of the busiest iron ore export ports in the world, was closed for more than 25 hours, including a stage four cyclone shutdown from 10:00 UTC on 7 February until 04:30 UTC on 8 February. Several liquefied natural gas export ports in the region were closed, including at Dampier and Ashburton, with the Dampier port being closed for a 52-hour period on 7–9 February. The ports at Walcott, Cape Preston, Barrow Island and Varanus Island also underwent precautionary shutdowns beginning at 22:00 UTC on 6 February. All non-essential employees were evacuated from the Karratha facilities operated by Woodside Energy.


 * Sandbags distributed to residents by Karratha SES
 * Non-essential port and mine staff evacuated by resource companies
 * Cyclone watches and warnings; blue/yellow/red alerts