Cyclone Yasi

Between 23 and 30 January, strong winds and swells were observed in Tuvalu, as Tropical Cyclones Wilma and Yasi developed and passed.[21][22] These strong winds delayed shipping schedules and affected students studying in Vaitupu and Fiji, and outer islands ran out of fresh supplies as a result of rough seas.[22] During 28–30 January, Yasi's precursor tropical depression caused rain and strong winds over the Fijian islands off Rotuma, Vanua Levu, Taveuni and the northern Yasawa Islands.[23]

During 30 January, Yasi became the second of three systems to directly impact Vanuatu in two months. Tropical Cyclone Yasi moved across Vanuatu's northern Torba Province, with winds reaching up to 95 km/h (60 mph).[24] Vanuatuan officials reported difficulties making contact with the Torba Province, but it was believed that the northern area escaped major damage.[25]

The storm was several hundred kilometres southeast of Papua New Guinea, but the outer edges of the large system brought strong winds, high seas and heavy rain to the country. In Milne Bay Province, local officials advised residents living along the coast to move to higher grounds.[26]

As Yasi moved into the Australian region meteorological data from the weather station on Willis Island was used to help monitor the system. Ahead of the system impacting the island, staff battened down the buildings and were evacuated off the island by a helicopter during 1 February.[27][28] Yasi subsequently passed directly over the weather station during 2 February, where wind gusts of 185 km/h (115 mph) and a minimum pressure of 937.9 hPa (27.70 inHg) were recorded, before the meteorological equipment and communications failed.[28] After the system passed over the island, it became clear that the strong winds and storm surge had damaged the radar, key observing systems as well as communications, operational and life support infrastructure. It was also noted that the system had altered the shape of the island and cleared most of its vegetation. Most of the automated surface observing systems and communications were subsequently restored and became operational, fifteen days after Yasi had passed over the island. However, the radar and life-supporting systems took a bit longer to restore and were subsequently completed by the end of November, before staff returned to the island during December 2011.[29]

By the time Yasi crossed into Australian basin, preparations for the storm were under way. Media outlets referred to the storm as "what could be the state's worst cyclone in history".[30]

Because of its great size, many feared that the tropical cyclone could cause damage more severe than Cyclone Larry in 2006 or Cyclone Tracy, which severely damaged Darwin in 1974.[31] Thousands of residents in the path of the storm were urged to evacuate by Queensland Premier Anna Bligh.[32] Thirty thousand people were evacuated from Cairns, including all patients from Cairns Base Hospital and Cairns Private Hospital who were airlifted by the Royal Australian Air Force and other agencies (such as the Royal Flying Doctor Service) to Brisbane.[33] The Queensland state emergency coordinator warned residents that they would be on their own for up to 24 hours, as the conditions would be too dangerous for emergency responders.[34]

Waves as high as 12 m (39.37 ft) were predicted to hit the north Queensland coast as the storm surge caused by Cyclone Yasi combined with a high tide of up to 7 m (23 ft) above average.[33][35]

In Mission Beach near where Cyclone Yasi made landfall, wind gusts were estimated to have reached 290 km/h (180 mph), leaving behind much damage.[36] A storm surge estimated to have reached 7 m (23 ft) destroyed several structures along the coast and pushed up to 300 m (980 ft) inland.[37] In the hours after the storm's passage, police could not venture beyond their station grounds as the situation had yet to be declared safe. Most of the beach had lost its sand and every structure was damaged to some degree. Near sunrise on 3 February, there were no reports of fatalities or injuries in Mission Beach.[38] As the eye of the storm moved over several towns in Queensland, news reporters took the opportunity to give brief damage assessments before the eyewall returned. The worst affected areas were around Tully, Tully Heads, Silkwood, Mission Beach, Innisfail and Cardwell.[39]

According to residents in Tully, the town was "...a scene of mass devastation". An unknown number of homes were completely destroyed as intense winds, estimated at 209 km/h (130 mph), battered the area. Many other homes not destroyed sustained severe facade and or roof damage.[40] As daybreak came, reports from the town stated that about 90% of the structures along the main avenue sustained extensive damage.[41]

Downed power pole and lines on Kings Road in Townsville

An evacuation centre in Innisfail began to flood as the worst of Yasi's impacts neared. Evacuees were reportedly hammering boards at the bottom of doors to prevent water from further entering the structure. Additionally, concerns over the building's windows came about as they flexed amidst winds over 200 km/h (120 mph).[42] In Townsville, numerous roofs were torn off buildings and sent hurtling down streets. Many windows are believed to have been broken as residents reported the sound of glass breaking throughout the night as the storm moved through.[43] In Tully, the high school was destroyed and will need to be rebuilt.[44]

Numerous emergency calls were made by residents trapped in their homes near the height of the storm. However, their calls could not be acted upon as conditions were too dangerous for police to travel in. One reported instance was of six people trapped in an apartment complex at Port Hinchinbrook near Cardwell, who could not be evacuated. The building was threatened by Yasi's storm surge which exceeded 3 m (9.8 ft). The group were later reported to be safe.[45] Around 10:30 pm local time on 2 February, Premier Bligh stated that an estimated 90,000 structures, including evacuation centres, were without power.[36] This figure rose to 170,000 by morning and officials stated that some residents may be without power for more than a month.[46]

The water-supply system had failed in Townsville and there was only 24 hours supply, while the water had run out at Magnetic Island in one day.[47]

Fears of total devastation to the banana and sugar cane crops arose as the storm struck land. Initial estimates stated that damage to sugar cane alone could reach A$505 million.[48] On 3 February, total losses from the storm were estimated to reach A$3.5 billion (US$3.54 billion), this makes it the costliest cyclone to ever hit Australia (not accounting for inflation).[49] By 5 February, A$2 billion (US$2.03 billion) was confirmed to have been lost in agriculture, mining and local government.[50] An additional A$1 billion has been lost in the tourism industry.[51]

One death was due to carbon monoxide poisoning by exhaust of a portable generator being used in a confined space at Bambaroo near Ingham.[52]

Two days after landfall, severe flooding from the rains severed the Bruce Highway between Townsville and Ingham leaving a 10 kilometre backup of traffic.[53] Many of those who evacuated the devastated areas including emergency workers were stranded.[53]

On 5 February, the remnants of Yasi as a tropical low created torrential rain as rainfall of 140 mm (5.5 in) was recorded in Terowie and Yongala.[54] Flooding was widespread in towns of northern South Australia reaching even Renmark on the River Murray.[54] In north-west Victoria, Mildura recorded the highest daily rainfall total on record, with 142 mm (5.6 in) and Lyndhurst, a suburb of Melbourne recorded 180 mm (7.1 in) of rain in the 24 hours falling up to 9am AEDT (22:00 UTC) on 5 February.[55]

On 6 February, the BOM reported that Ex-Tropical Cyclone Yasi was 85 km (53 mi) north of Yulara[56] and that heavy rains continued in the Alice Springs area. The deluge also continued in northern South Australia as vast areas continued to get rain.[57] Hallett had a record rainfall amount of 98 mm (3.9 in).[57] Damaging winds with gusts of more than 90 km/h hit Marla and Coober Pedy.[57] More than 100 mm (3.9 in) also fell at Arkaroola and Mt Dare, 92 mm (3.6 in) fell at Marree, and 86 mm (3.4 in) at Yunta.[57]

Even one week after the flooding rains, areas that were affected had become completely isolated.[58] At Challenger Gold Mine 150 people were isolated and emergency supplies had to be flown in. Cattle Stations near Oodnadatta, Glendambo and the world's largest at Anna Creek Station were all isolated.[58]

The Australian Defence Force (ADF) response was designated Operation Yasi Assist. The ADF established Joint Task Force 664, based at Lavarack Barracks in Townsville and under the command of Brigadier Stuart Smith, for operational command on 2 February 2011.[59]