Tropical Cyclone Yasi – la Nina
La Niña is the name for the cold phase of ENSO, during which the cold pool in the eastern Pacific intensifies and the trade winds strengthen.
· Natural Disaster
o Yasi was a category 5, (Australian Scale [4 on SSHS]) tropical cyclone in February 2011. It had formed as a tropical low on 26 of January in southern Fiji, in the tropics as a tropical storm. It travelled towards Australia’s north-eastern coast at about 70km/h. As la Nina took effect, the Cyclone reached 120, then 160km/h, rocketing towards the Australian east coast.
· How la Nina effected the Natural Hazard
o La Nina is the reason for all the terrible weather this year. The weather is opposite of El Nino, as there is a lower ocean surface temperature and atmospheric pressure. Results of La Niña, in the southern hemisphere, the rainy season generally has heavier rainfall and stronger tropical cyclones.
· Preparations
o Thirty thousand residents of Cairns were evacuated temporarily to live in Brisbane for at least 3-4 days until the cyclone had passed completely. Patients of hospitals were airlifted by the RAAF and RFDS to Brisbane.
· Social Impacts
o More than 10,000 homes were to be flooded. This would have been terrifying for the local resident of Innisfail and Cairns. Approximately 30,000 people were evacuated and about 350,000 people were to be affected by the severe cyclone. This would have affected the society because of the aftermath of the events of the economy, and agricultural results with the shortage of food.
· Environmental Impacts
o The Great Barrier Reef was the most destroyed environment in the cause of cyclone Yasi. 300 of the total 2,398 km were affected by the cyclone. The areas that were affected are Solomon Islands, Vanuatu, Papua New Guinea, Queensland, South Australia, New South Wales, Northern Territory and Victoria.
· Economic Impacts
o The cyclone’s main impact areas were Innisfail and Cardwell, the heavily populated agricultural and tourist region. Right next door the Great Barrier Reef! This caused more money to be put into cleaning up and rebuilding the cities rather than into the agricultural and tourism. Approximately $3bn worth of damage to the two cities.
· Duration
o Yasi formed on January 26th 2011. It intensified into a cyclone category (3) on 31st January, then a category 4 on the 1st of February. February 2nd, the cyclone strengthened to a category 5 system.
· Local Effect
o Premier Anna Bligh told residents that they had about three hours to get out before cyclone Yasi started to pelt the Queensland coast just hours before the full brunt of Cyclone Yasi had hit .The Bureau of Meteorology had warned the storm is "likely to be more life threatening than any experienced during recent generations" and predicted winds of up to 320km/h and 2m tidal storm surges. This would have terrified the residents of Innisfail.
· State Effect
o 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. Sfter the cyclone had passed, the state fire brigade, police force and emergency responses were immediately dispatched and sent to the worst affected areas.
· Federal Effect
o The Australian Defence Force response was designated Operation Yasi Assist. The ADF established Joint Task Force 664, operational command on 2 February 2011.
