Residents in north Queensland are being warned to prepare now as the worst tropical cyclone since Yasi six years ago bears down on the coastline.
The Bureau of Meteorology expects the "very destructive core" of Debbie to cross the coast between Townsville and Proserpine as a category four early tomorrow.
Winds of up to 260km/h are expected, with a potential storm surge which could flood areas across the region.
Last night, authorities began evacuating parts of the Whitsunday region. The Whitsunday Regional Council listed several low-lying areas.
Whitsunday Mayor Andrew Willcox urged residents to seek shelter with family or friends at higher ground.
"If you are unable to evacuate, the Cyclone Shelters in Bowen and Proserpine will be opened [today] as a last resort," he said.
Residents in low-lying areas that are not under the evacuation order are being advised to voluntarily evacuate.
The BoM's deputy regional director in Queensland, Bruce Gunn, says areas far from the storm's centre will still face category 3 winds and potential flooding.
"Queensland hasn't seen a coastal crossing for a couple of years now since Marcia or Nathan in 2015 but I think you could probably say that Debbie's the most significant tropical cyclone since Yasi," Gunn said.
"Not so much because of it's intensity ... mostly because of its size and extent. It's quite a sizable system."
More than 1000 emergency services personnel have already been sent to the region.
Authorities are however urging people in the area to prepare now and be prepared to evacuate if ordered to.
"Tomorrow will be too late," State Disaster Coordinator Michael Gollschewski said. "Just because they may be some way away from that area that doesn't mean you may not be impacted. People need to be aware of what will be happening in their area."
Schools between Ayr and Prosperpine are being closed from today.
Yasi, a category five cyclone, caused A$800 million in property damage when it tore across north Queensland in February 2011 with structures in Townsville, Innisfail, Tully, Cardwell and the Dunk Island resort affected.
Hundreds of power workers are on standby across the region and local hospitals are prepared for the days ahead.
At Airlie Beach preparations are low-key, with several holiday makers preparing to ride out the storm or even continue their travels across the region. A local tour operator said a handful of backpackers were still preparing to head north to Townsville and Cairns and did not appreciate the risk.