Largest evacuation ever under way in NT

Greg Roberts
Tropical Cyclone Trevor is set to move towards the Northern Territory over the weekend

The largest evacuation before a cyclone in the Northern Territory's history is underway with Cyclone Trevor due to make landfall on Saturday.

More than 1000 residents have been evacuated from Groote Eylandt and Numbulwar with another 1000 people being moved out of Borroloola, the McArthur River zinc mine, Robinson River and other communities all along the Gulf of Carpentaria coast to Queensland.

The severity and threat of the storm, as well as complications with the remoteness of the area, led to the decision to evacuate, Chief Minister Michael Gunner said on Thursday.

A state of emergency has been declared in the Gulf country, with schools closed and police can order people to evacuate and close roads and businesses.

It is the largest evacuation prior to a cyclone in the territory's history and largest type of any evacuation since Cyclone Tracey.

The entire NT Gulf coast is on flood watch with gale-force winds, heavy rain and storm surges extending 300km from the eye of the cyclone.

"As Cyclone Trevor tracks across the Gulf of Carpentaria, the Bureau of Meteorology is forecasting that the cyclone will make landfall between Borroloola and Groote Eylandt during Saturday as a category four severe tropical cyclone," he told reporters.

"Marine conditions in the gulf are deteriorating from this morning."

Very destructive winds, with gusts to 260 km/h, heavy rainfall and a dangerous storm tide are expected near the cyclone centre as it approaches and crosses the coast, said the bureau's Todd Smith.

Rainfall totals of 100mm to 200mm per day will hit ground "hard-baked" by the drought in recent months, meaning likely flash flooding that will affect pastoralists.

Mr Smith has not ruled out the storm strengthening to a category five with winds of more than 300km/h.

The last time a cyclone this strong hit the Territory was Cyclone Lam in 2015 but Trevor is far bigger, Mr Smith said.

Australian Defence Force Hercules' aircraft are being used to transport people, who have begun arriving in Darwin and Katherine where indoor sleeping facilities are being set up at local showgrounds .

That includes creating barriers to ensure Indigenous cultural protocols are followed and people are spoken to in local languages.

"We've used buses, vehicles, ferries, planes, helicopters and anything else in between we can get out hands on," police regional controller Travis Wurst said.

About 600 out of Groote Eyland's population of 2800 have been evacuated but authorities are now focusing on Borroloola, with a population of 900.

The evacuations are starting with the most vulnerable and people who are not evacuated in time will be moved into emergency shelters.

"We have the capacity and capability to look after them as long as we need to, until water and power are safe again and houses are habitable again," Mr Gunner said.

Trevor left behind trail of destruction in Queensland's Cape York peninsula earlier this week, uprooting trees, caused flooding and roof damage, closed schools and roads and downed power lines.

Trevor lashed the Aurukun community overnight and some 180 homes remain without power on Thursday as residents began cleaning up.