Severe Tropical Cyclone Heidi was a small and strong

tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

that struck

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

in January 2012. The seventh tropical low, third tropical cyclone, and second severe tropical cyclone of the

2011–12 Australian region cyclone season The 2011–12 Australian region cyclone season was a below average tropical cyclone season, with 7 cyclones forming rather than the usual 11. It began on 1 November 2011, and ended on 14 May 2012. The regional tropical cyclone operational plan d ...

, Heidi developed from a tropical low that formed to the south of Indonesia on 9 January, before strengthening into a Category 1 tropical cyclone on the following day. Tracking southward towards the

Pilbara coast The Pilbara Coast is the coastline of Western Australia's Pilbara region. It is often referred to as the North West Coast of Western Australia. It is a complex array of river mouths, ports, peninsulas, and islands. Geography North West Cap ...

in a favourable environment, Heidi

rapidly intensified Rapid intensification (RI) is any process wherein a tropical cyclone strengthens very dramatically in a short period of time. Tropical cyclone forecasting agencies utilize differing thresholds for designating rapid intensification events, th ...

and attained Category 3 severe tropical cyclone status on 11 January. After making landfall at peak intensity later that day with estimated winds of , Heidi rapidly weakened, dissipating over Western Australia by 13 January. In advance of Heidi's arrival, the

Port of Port Hedland Port Hedland is one of the largest iron ore loading ports in the world and the largest in Australia. In 2022, it had the largest bulk cargo throughput in Australia. With the neighbouring ports of Port Walcott and Dampier, Port Hedland is one ...

, offshore and coastal oil rigs and iron mines were shut and workers moved out of the area. Alerts were issued for much of the Pilbara coast, and the Port Hedland International Airport was shut. Heidi dropped heavy rainfall across the

Pilbara The Pilbara () is a large, dry, sparsely populated regions of Western Australia, region in the north of Western Australia. It is known for its Indigenous Australians, Aboriginal people; wealth disparity; its ancient landscapes; the prevailing r ...

and

West Kimberley West Kimberley is a sub region of the Kimberley region of Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern T ...

regions in Western Australia, with a maximum accumulation of being reported at

Pardoo Station Pardoo Station is a pastoral lease, formerly a sheep station, and now a cattle station approximately east of Port Hedland and north of Marble Bar, in the Pilbara region of Western Australia. Description The property used to be about in s ...

. These heavy rains lead to minor flooding on roads in the region. In addition, strong winds knocked out winds and caused major power outages in South Hedland and Wedgefield. Overall, Heidi caused only minor damage and no deaths; nonetheless, the name ''Heidi'' was later retired from the rotating list of storm names assigned by the

Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Government of Australia, Australian Government that is responsible for providing Weather forecasting, weather forecasts and Meteorology, meteorological services to Australia a ...

Meteorological history

The origins of Heidi can be traced to a tropical low that was first noted by TCWC Perth about south of Sawu, Indonesia on 9 January 2012. Located in an environment favourable for development, characterised by low northerly

wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical ...

, divergence due to an upper-level trough to the south over central Western Australia, good poleward outflow to the south and sea surface temperatures (SSTs) of 28 to 31 °C till the Pilbara coast, the low tracked southwards quickly and intensified into a Category 1 tropical cyclone at 1200 UTC on 10 January. The

Joint Typhoon Warning Center The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...

(JTWC) estimated that Heidi intensified into a tropical storm six hours later. When it first developed, Heidi was a small tropical cyclone, with gale-force winds extending outward from the centre of the cyclone. Owing to the highly favourable environment and its small size, Heidi rapidly intensified after genesis. The system continued to track southwards while decelerating and contracting in size, and intensified to Category 2 strength six hours after being named. Heidi intensified into a Category 3 severe tropical cyclone at 1200 UTC on January 11, and six hours later attained its peak intensity with ten-minute sustained winds of and an estimated minimum central pressure of 960 mbar (hPa). At the same time, the JTWC estimated Heidi to have one-minute sustained winds of . Heidi made landfall about east of Port Hedland a couple of hours later at peak intensity. At landfall, gale-force winds extended only outwards from the centre of the tropical cyclone. Heidi rapidly weakened over land: the cyclone fell to Category 2 strength within ten hours of landfall, and the system weakened to Category 1 strength in another six hours. Heidi weakened into a tropical low by 1800 UTC on January 12, which was last noted by TCWC Perth as well as the JTWC 12 hours later.

Preparations and impact

In advance of the approach of Heidi, the BoM issued a cyclone warning for the coast from Sandfire to Mardie. The

Karijini National Park Karijini National Park is an List of national parks of Australia, Australian national park centred in the Hamersley Ranges of the Pilbara region in the northwestern section of Western Australia. The park is located north of the Tropic of Capricor ...

was shut, and the

was cleared and shut formally by 2 a.m. on 11 January. Non-essential port and construction workers were moved out and iron mines in the Pilbara coast were shut in preparation for Heidi. Oil rigs offshore and along the Pilbara coast halted their activities in the lead-up to Heidi. The Port Hedland International Airport was shut, and

Qantas Qantas ( ), formally Qantas Airways Limited, is the flag carrier of Australia, and the largest airline by fleet size, international flights, and international destinations in Australia and List of largest airlines in Oceania, Oceania. A foundi ...

cancelled two afternoon return services. The 300 affected passengers were provided with one night's accommodation by the carrier. A red alert was issued by the BoM for the coast between Pardoo and

Whim Creek Whim may refer to: * Whim, U.S. Virgin Islands, a settlement * Whim (mining), a capstan or drum with a vertical axle used in mining * Whim (carriage), a type of carriage * ''Whim'', a reissue of ''Adventures of Wim'', a book by George Cockroft as ...

, and a blue alert for island communities between Whim Creek and Dampier. The residents of Port Hedland were advised to immediately seek shelter, and people in the surrounding areas were urged to gather food, water, torches, portable radios and first aid kits. Residents from Port Hedland to Wallal were warned against

storm surge A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the ...

that could inundate low-lying areas. About 45 people took shelter in a relocation centre in South Hedland overnight. The small, destructive core of Heidi missed Port Hedland to the east. Nonetheless, very strong winds and heavy rainfall caused minor flooding and power outages, and trees were uprooted across properties. According to

Horizon Power Horizon Power is a power company that provides power supplies to Western Australia owned by the Government of Western Australia. Horizon Power was established on 1 April 2006 after Western Power Corporation was split up. It operates in the Pil ...

, more than 3,500 homes and businesses in Port Hedland lost power due to Heidi. Though the threat of the storm surge did not eventuate as the storm slowed before landfall and as landfall occurred more than four hours after the high tide, heavy rainfall of over led to flooding in the region. of rainfall was reported in 24 hours at

, while Port Hedland Aerodrome recorded of rain. Overall, damage due to Heidi was relatively minor, and no casualties were reported. The name ''Heidi'' was retired by the Bureau of Meteorology from the rotating list of names used for tropical cyclones in the Australian region following the season, and replaced with ''Hayley''.

References

External links

Australian Bureau of Meteorology
{{DEFAULTSORT:Heidi (2012)

Heidi ''Heidi'' (; ) is a work of children's fiction published between 1880 and 1881 by Swiss author Johanna Spyri, originally published in two parts as ''Heidi: Her Years of Wandering and Learning'' () and ''Heidi: How She Used What She Learned'' ( ...

Heidi 2012 Heidi 2012

Retired Australian region cyclones 2010s in Western Australia

Meteorological history

Preparations and impact

See also

References

External links