Evacuations have been ordered in coastal towns and communities of the Whitsundays council area in north Queensland as Tropical Cyclone Debbie bears down, with authorities warning of damaging tidal surges.
The system is likely to cross the Queensland coast as the worst cyclone since Yasi hit as a category five in 2011, the Bureau of Meteorology (BOM) warned.
Graphic: Commonwealth of Australia 2017, Bureau of Meteorology
Tropical Cyclone Debbie remains on track to be a severe category four cyclone when it makes landfall on Tuesday morning "somewhere near Ayr", BOM Queensland regional director Bruce Gunn said at the Premier's media briefing today.
"I think you could say that Debbie's probably the most significant tropical cyclone since Yasi that we've had to deal with in Queensland," he said.
"Not so much because of its intensity, we're only predicting a category four at landfall, but mostly because of its size and extent."
Tidal surge is shaping as a major concern for authorities, given the extensive damage caused by the ocean as Yasi crossed the coast.
As a result, Whitsunday Regional Council ordered a police-enacted evacuation of areas designated red and orange zones under local disaster planning.
This covers coastal communities from Cape Upstart, north of Bowen, to Lethebrook, south of Proserpine.
Debbie strengthened to a category two system overnight and at 10:00am was about 500 kilometres east north-east of Townsville and 395km east north-east of Bowen, moving south-west at 6km per hour.
The Bureau of Meterology is expected to upgrade the system to category three this afternoon.
Senior forecaster Andrew Carnes said it would continue to strengthen and its path was very hard to predict.
"If you're further north than that Burdekin area and you think we're out of the woods now - we're certainly not," he said.
In Townsville, the local disaster management received a briefing from the BOM as it prepared the city for the cyclone's impact.
Earlier today, forecaster Adam Blazak said Debbie would be severe and had to be taken seriously.
"You're splitting hairs between a category four and category five - they're both severe cyclones and we really need to be taking this one quite seriously," he said.
"Winds of up to 250 kilometres an hour are likely when it crosses the coast, causing extensive property damage with roofs torn off homes, power down, trees knocked over and caravans destroyed."
Townsville Mayor Jenny Hill said residents should not be complacent.
"Over the next few days we have to keep monitoring it and we have to assume the worst, which is why we're asking people to prepare themselves now in case we require them to evacuate," she said.
Burdekin Shire Mayor Lyn McLaughlin said some residents had already left the region as a precaution.
She said the council was encouraging people to stay with family and friends elsewhere if they did not feel safe to shelter in their homes.
"We don't actually have a cyclone shelter in the Burdekin so we are encouraging people who are wanting to shift from their house to stay with family and friends, we know there are people who have left the district to go elsewhere to wait to see what happens," Cr McLaughlin said.
Energy Minister Mark Bailey said the first of more than 200 Energex workers had begun the journey northwards from Brisbane this morning in preparation for the clean-up after the cyclone crosses the coast.
"They're going by road because they're taking all their kit and equipment with them," Mr Bailey said.
"They're going to Rocky tonight to overnight there and we'll see where the cyclone tracks during the day and there'll be a decision made about where they're based after that."