Communities in north-east Arnhem Land and along the Cape York peninsula should prepare for a cyclone to hit this weekend.
The Bureau of Meteorology advised residents be on cyclone watch at the NT's Milingimbi to Cape Shield, including Nhulunbuy, and at Queensland's Gilbert River Mouth to Thursday Island, including Weipa.
Emergency kits, homes and yards should be prepared, and residents should decide now where they will shelter.
On Thursday morning, the tropical low was 320 kilometres north-west of Nhulunbuy.
If the tropical low takes a more southerly track, gales could develop between Milingimbi and Cape Shield, including Nhulunbuy, during Friday afternoon.
In Queensland, gales could develop in areas between Thursday Island and Gilbert River Mouth, including Weipa and Kowanyama, by Saturday.
Heavy rainfall is forecast about Torres Strait and Cape York over the coming days, which could potentially lead to flash flooding in parts.
Abnormally high tides may develop between Torres Strait and Karumba as the system moves closer to the eastern Gulf of Carpentaria coast.
Large waves will become possible about foreshore areas.
The tropical low will be called Nora if it develops into a cyclone.
Workers race to prepare shelter
Chief Minister Michael Gunner said workers were rushing to repair an emergency recovery centre so it could house displaced people in Darwin before the expected tropical cyclone hit north-east communities.
During last Saturday's cyclone a large number of trees fell around Foskey Pavilion and caused power outages at the Darwin showgrounds, which is where residents would be evacuated to.
"I want to make sure if there is anything that happens out there ... that we are in a position here in Darwin to support any displaced residents," Mr Gunner said.
Tropical Cyclone Marcus gets political
As isolated parts of the Territory brace for an expected cyclone, political leaders weighed in on the response to Tropical Cyclone Marcus.
Federal Opposition Leader Bill Shorten said it "was a miracle that there wasn't serious injury or loss of life" during the storm, after surveying post-cyclone Darwin on Wednesday.
"I'm not sure that people in other parts of Australia quite realised the extent of cyclone Marcus and the impact it had on Darwin," he said.
When asked if he believed Prime Minister Malcolm Turnbull's was one who had not realised the full extent of the cyclone, given his noted silence about the event, Mr Shorten said he "wasn't going to get too political".
But he went on to say he believed leaders were obliged to be there when people were doing it tough.
Mr Shorten promised to be all over insurance companies "like a tonne of bricks" if they delayed paying claims promptly.
While he said he'd talk to NT politicians about other measures to "catastrophe-proof" the region's infrastructure, he said priorities would be determined after the clean-up.
NT Opposition Leader Gary Higgins derided Mr Shorten for visiting the Darwin region on Wednesday, claiming he came purely for the post-cyclone photo shoot.
"We really need to look at the political stunt today and the cost of, how much it's costing taxpayers, for Bill Shorten to come up here today for a photo opportunity," Mr Higgins said.
"It's got to be one of the most expensive photo opportunities that I've ever seen."
Five days without power
When asked if the NT Government should shelve plans for a $30 million underground carpark to spend money on underground power lines instead, Member for Johnstone Ken Vowles said the Government "had to look at everything".
But he said he would take the calls for underground powerlines from residents in his electorate to cabinet.
"That's what governments do, we have to have those discussions...certainly it has been raised many times about underground cabling and that discussion will keep ongoing," Mr Vowles said.
About 1,500 Darwin households remained without power five days after cyclone Marcus hit Darwin.
Directly after the cyclone swept through 26,000 homes lost power.
General Manager of System Control Malcolm Conway said about 900 customers were awaiting transformers and poles to be restored, and street infrastructure to be repaired, before power could be restored to their homes.ABC