About 25,000 people have been told to evacuate as a cyclone carrying winds of up to 275km/h (170 mph) moves towards the Queensland coast.
Cyclone Debbie has intensified into a Category 4 system and is due to make landfall early on Tuesday local time.
Some people have refused to leave despite warnings the destructive core could be as wide as 100km (62 miles).
Queensland Premier Annastacia Palaszczuk said the storm would rival the devastating Cyclone Yasi in 2011.
Late on Monday, Ms Palaszczuk urged 25,000 residents in low-lying areas of Mackay to immediately find safer ground. More than 5,000 other Queenslanders were already evacuating their homes.
"The time for people to move is now," she said.
A state on edge
In its latest update, Australia's Bureau of Meteorology said the cyclone could "intensify further" as it moved towards the Queensland coast.
It is expected to make landfall sometime after 07:00 on Tuesday (20:00 GMT Monday) anywhere in a 265km zone from Townsville to Proserpine.
"That is the uncertainty of cyclones," said Bureau of Meteorology regional director Bruce Gunn.
Media captionQueensland prepares for imminent arrival of Cyclone Debbie
Authorities warned the cyclone could coincide with high tide, which is expected to peak at 3.2m. The storm surge could add an additional 4m, Ms Palaszczuk said.
More:
http://www.bbc.co.uk/news/world-australia-39402106
