Flood-devastated Queensland braces for cyclone
Australia braces for cyclone
Category 4 Tropical Cyclone Yasi forecast to hit North Queensland on Wednesday
Authorities warn 200km/h winds, flooding from storm could be life-threatening
Hundreds evacuated from areas at risk, including patients airlifted from hospitals in Cairns
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(CNN) -- The Australian state of Queensland, already hit by deadly flooding in recent weeks, is bracing for more devastation as a huge tropical cyclone rages towards its coast.
Hundreds of patients have been evacuated from hospitals in the far north Queensland town of Cairns, and residents are being told to leave their homes as category four Cyclone Yasi closes in.
The storm -- expected to pack winds of more than 200 km/h (125mph) -- is forecast to make landfall between Cairns and Innisfail after 7pm local time on Wednesday.
Experts say it will bring torrential rain and cause a storm surge of up to two meters above the usual high tide line, flooding low-lying areas along the coast.
Deputy Police Commissioner Ian Stewart warned the state faces "one of the most significant weather events" in its history.
"This is a life-threatening storm, and people need to understand that they have a final window of opportunity to self-evacuate," Stewart said.
It will be a display of the awesome power of nature, but it's not something you want to go outside and watch
"In the hours that are left, people need to make their final preparations to either shelter in place, or evacuate."
The state's premier, Anna Bligh, has urged residents in the threatened areas to take sensible precautions, and to stay inside once the storm hits.
"These will be highly destructive winds... they will be life-threatening if people make it their business to go outside in them.
"Loss of life and serious injury ultimately depends on people being sensible, listening to the warnings, taking advice and not treating this as a tourist event.
"It will be a display of the awesome power of nature, but it's not something you want to go outside and watch."
More than 250 patients -- including premature babies, those in intensive care, and on dialysis -- are being airlifted to facilities in Brisbane for treatment after the storm forced the closure of two hospitals in Cairns.
"We understand this will cause some anxiety, but it is only being done to make sure that very ill, very vulnerable patients are in the safest place possible," said Bligh.
More than 20 people died and thousands of homes were wrecked when severe flooding hit Queensland in January, affecting 3.1 million people.
Australia's Prime Minister, Julia Gillard, has announced a one-off flood tax aimed at helping to pay for the estimated AUS $5.6 billion (US $5.58 billion) damage caused.