Preparations underway at a used car dealership in Cairns

Australia's populated coast has never before seen a threat on the scale of monster Cyclone Yasi and the potential for death is very real, Queensland Premier Anna Bligh says.

The Bureau of Meteorology says category five Yasi is likely to be more life-threatening than any in recent generations.

Cairns Mayor Val Schier says Yasi is the most severe cyclone in Australia's living memory and Cairns could see scenes akin to Cyclone Tracy, which flattened Darwin in 1974.

Yasi will bring winds close to, and possibly in excess of, 300km/h when it makes landfall likely between Cairns and Innisfail about 10pm (AEST) on Wednesday.

"This is the most severe, most catastrophic storm that has ever hit our coast," Ms Bligh told the ABC.

"Frankly, I don't think Australia has ever seen a storm of this size, this intensity in an area as popular as this stretch of our coast."

She said winds in excess of 280km/h would last for 24 hours and associated flooding would be felt for days, possibly as far inland as Mt Isa near the Northern Territory border.

Ms Bligh said there'd been grave developments overnight, with Yasi's landfall time brought forward and now expected to come in on a high tide, exacerbating potentially deadly storm surges along the coast.

"We've seen a number of worst case scenarios come together.

"We are facing an event that will be terrifying."

Ms Schier says the city could see Cyclone Tracy-like scenes and that anyone who decides to stay in homes in unsafe areas is on their own.

"We look to what happened with Cyclone Tracy where people ended up under mattresses in bathrooms and that may be the situation here ..." she told the ABC.

She said Cairns could expect horrific, terrifying winds for 10 hours either side of the time of landfall.

"That's going to be terrifying to children and animals and adults as well."

She added: "... if people want to stay (in unsafe locations), they're taking responsibility for their own life."

Cairns council officials said the region would see 90km/h winds from 10am; 125km/h from midday, and 200km/h winds by Wednesday evening.

Only two of the seven evacuation centres opened in and around Cairns are cyclone rated, with the others located in new buildings authorities hope will withstand Yasi's fury.

"They should be OK but we can't guarantee safety, of course," the mayor said, adding people were still being advised that homes in safe locations were the best places to shelter."

Senior bureau forecaster Gordon Banks said Yasi could take at least 24 hours to weaken after it makes landfall.

"There's still potential for it to become stronger ... as a strong category five we could see wind gusts in excess of 320km an hour, which is just horrific," he told the ABC.

Ms Bligh said extra emergency services personnel had been sent to north Queensland, with so many communities, including the city of Townsville, expected to feel Yasi's fury.

AAP

All affected residents are being urged to register their details with the National Registration and Inquiry System (NRIS) by phoning 1300 993 191 or by visiting www.redcross.org.au

People wishing to make enquiries about family or friends affected by the emergency can call the NRIS on 1300 993 191, or if phoning from overseas + 61 7 3055 6220.