Cyclone Lua

Pre-Landfall 1 | Summary
Posting Date: March 16, 2012, 11:30:00 AM

The fifth cyclone of the season in Australia, Cyclone Lua is poised to make landfall as a strong Category 3 storm (on the Australia tropical cyclone scale) sometime tomorrow morning between Pardoo and Walall. This region is home to Australia's largest iron ore port as well as several oil and gas facilities.

Current Conditions

As of the Australian Bureau of Meteorology (BOM) 8:52 p.m. WST advisory today, Cyclone Lua was about 390 kilometers north-northwest of Port Hedland and 495 kilometers west-northwest of Broome. The BOM said that Lua has intensified to a severe tropical cyclone since yesterday. Its maximum sustained winds currently are 195 kilometers per hour with higher gusts, a strong Category 3 on the Australian scale and a Category 2 hurricane on the Saffir-Simpson Scale. The BOM categorizes tropical cyclones according to 3-second gust wind speeds rather than the 1-minute sustained winds used by the Saffir Simpson scale, or the 10-minute sustained winds used by many other meteorological agencies around the world. Cyclone Lua is moving toward the east southeast at 19 kilometers per hour. A cyclone warning is in effect for coastal areas from Cape Leveque to Dampier, including Port Hedland, Karratha, Dampier and Broome, as well as inland parts of the eastern Pilbara and far western Kimberley. Although Lua is forecast to briefly reach category 4 strength, at present the storm is expected to cross in the hurricane warning area and make landfall by tomorrow midday as a strong category 3 cyclone.

Exposure at Risk

The largest concentrations of exposure near the BOM’s most likely track are the cities of Port Hedland and Broome. Both cities will be outside of the main area of strong winds, which will serve to mitigate most of the wind damage. Along the Pilbara coast, mining towns such as Karratha and Dampier have historically suffered significant losses from tropical cyclones. After Cyclone Tracy in 1974, building codes were revised and disaster planning was enhanced greatly. Mandatory building codes for wind resistance are in effect in many cyclone-prone areas of Queensland and Western Australia. Additionally, because of the history of intense cyclones in this area of Western Australia, wind speeds for structural design are higher than in other parts of the country. However, while building code enforcement is generally stringent across Australia, each state and territory is responsible for enforcing its own building and construction standards. At the expected wind speeds, wind-related structural damage is not expected to be significant. However, damage to the roof frames and roof coverings of homes and businesses may occur, while windows and cladding on engineered structures could be damaged by impact from debris. Most commercial or industrial insured structures on Australia’s west coast are made of concrete and steel, which perform well.

Reported Impacts

Lua formed near the major oil and gas producing area of Australia. Australia’s main iron terminals, including Rio Tinto, BHP, Fortescue, have suspended production in advance of Lua’s arrival. Lua has shut down 103,800 barrels a day of oil output, compared with Australia’s daily production of about 393,000 barrels last year. The only highway connecting Broome and Port Hedland has been closed. All commercial flights in and out of the area have been cancelled. Evacuation centers have been set up in Port Hedland and South Hedland and Marble Bar. Lua has already produced up to 250 mm of rainfall according to satellite estimates and likely will bring similar maximum totals near the location of landfall. Also, large and destructive waves are expected to batter the stretch of coast from Port Hedland east to Bidyadanga. Tides are likely to rise significantly above the normal high tide mark, causing significant coastal flooding.

Track and Intensity

With wind shear forecast to weaken over the next day, Cyclone Lua is expected to continue intensifying—possibly to a Category 4—before weakening to a category 3 (winds 118-159 kilometers per hour) just before landfall near Port Hedland at 02:00 GMT (roughly 2 a.m. local time) tomorrow. After landfall, the BOM forecasts the storm to track almost due south, dropping below cyclone status approximately 24 hours after landfall. Cyclone Lua’s track bears similarities to that of Cyclone Laurence, which crossed the sparsely populated Pilbara coast in 2009 as a Category 4 cyclone but caused minimal impact to the insurance industry. Given the relatively sparse population in the landfall location, AIR does not expect significant insured losses from Lua. As always, however, there remains uncertainty and the AIR tropical cyclone team will provide updates if warranted.

Pre-Landfall 1 | Downloads
Posting Date: March 16, 2012, 11:30:00 AM