Canberra, April 13 : The state of Western Australia is bracing for a powerful category four cyclone -- deemed to be the strongest in a decade to hit the region. In its latest forecast, Australia's Bureau Of Meteorology (BOM) said tropical cyclone Ilsa is predicted to strike some 500 kilometre west of Broome and the storm's "very destructive core" could gust up to 275 km/h on Thursday night into Friday morning, before it moves inland, reports the BBC. Australia uses a five-tier system to categorize cyclones, and on Thursday it strengthened to a Category 4 cyclone. The BOM also warned of up to 400 mm of rain and abnormally high tides, with the storm's impact felt across a 600 km region from Port Hedland to just south of Broome. Authorities have issued a yellow alert, which orders people to be ready to shelter, for several remote towns including Port Hedland, a town of 15,000 which is the world's biggest iron ore exporting port. Port Hedland mayor Peter Carter said evacuation centres have been set up in the town. "Everyone is on edge," the BBC quoted Carter as saying to the Australian Broadcasting Corporation. "They understand that cyclones are what they are. They're very, very unpredictable." Some 700 residents from the remote community of Bidyadanga were being evacuated, the fire service said. Cyclones are common on the west coast of Australia, with the BOM logging seven of them last year, reports CNN. The northern coast of Western Australia has been hit by 13 storms equivalent to a Category 4 hurricane since 1960, but this would be the first since tropical cyclone Laurence in 2009, which hit in a very similar location with winds of 240 kph at landfall. The strongest storm ever to hit any part of Australia was tropical cyclone Monica, which arrived in 2006 with sustained winds around 290 kph, as it swept across the eastern and northern parts of the country. /IANS