BOSTON, March 16, 2012 – According to catastrophe modeling firm AIR Worldwide, 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.
As of the Australia 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. 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.
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.
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.
According to AIR, 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.
At the expected wind speeds, wind-related structural damage is not expected to be significant, according to AIR. 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.
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.
According to AIR, 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.
Along the Pilbara coast, mining towns such as Karratha and Dampier have historically suffered significant losses from tropical cyclones. According to AIR, 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.
AIR does not expect significant insured losses from Lua and is continuing to monitor the situation.