Severe Tropical Cyclone Debbie has been upgraded to a Category 4, making it one of the strongest to hit Queensland in years.
Thousands of residents of the north Queensland coastline have been evacuated from the path of approaching cyclone.
Weather watchers say it's the most powerful storm ever to threaten north-eastern Australia.
The storm is expected to hit the coastline between Mackay and Townsville.
Australia's Sunrise programme's weather presenter Sam Mac told the AM Show says the situation is "extreme".
"It was upgraded to a Category 4 last night which was much earlier than it was expected to be upgraded to a Category 4."
Around 20,000 people have been asked to evacuate around the Mackay area.
"That is a lot of people to be told to get up and get out and that's been happening since early afternoon yesterday," he says.
Residents have had plenty of warning, and Mac says locals are used to this kind of severe storm.
It's been a rough night for the resort area of Airlie Beach in Queensland's Whitsunday Coast; Mac says there's been "howling winds" with boats in the marina "thudding" together.
He compared the conditions to "standing next to a jet that's about to take off".
"You really have to shout to hear yourself, it's extreme and the doors and shaking together. The power is immense and it's going to get more powerful."
A Category 4 storm can bring sustained winds of up to 150km/h, and winds in some parts of Queensland have so far been hitting 140km/h.
The towns of Mackay, Sarina and Hamilton Island are expected to take a direct hit from Debbie when she makes landfall early on Tuesday afternoon (NZ time).
"Everyone is bracing themselves for that impact from Tropical Cyclone Debbie," Mac says.
Although emergency services are taking calls, in most places they are not responding because it's simply too dangerous.
Instead, they are logging details to respond later in the day.