Cyclone is expected to hit Australia tonight
UPDATE 1pm: TROPICAL Cyclone Marcus has formed off the NT north coast and an official Cyclone Warning is now in effect for Darwin, as the storm looms 310km outside the Top End capital.
In its latest update the Bureau of Metorology warns the cyclone is moving southeast at 13km/h.
Other areas within the warning zone include Maningrida to Daly River Mouth and the Tiwi Islands, while the warning for Maningrida to Milingimbi has been cancelled.
The Daly River Mouth to Mitchell Plateau remain on cyclone watch.
The weather bureau advises Cyclone Marcus is now a category 1 storm with sustained winds near the centre of 65 kilometres per hour and wind gusts of up to 95 kilometres per hour.
The bureau says tropical Cyclone Marcus will most likely cross the Cobourg Peninsula tonight.
The tropical cyclone is then expected to turn south towards the southwest, passing close to Darwin during Saturday, before moving into the Timor Sea late on Saturday or early Sunday.
Cyclone Marcus is expected to approach the north Kimberley coast later on Sunday.
Gales with gusts up to 110km/h are expected to develop over the Cobourg Peninsula during this afternoon, then extend to Gouburn Island later this evening.
Gales may also extend to Maningrida tonight if the tropical cyclone takes a more easterly track.
A bureau spokeswoman said the gales were expected to extend to Darwin and the Tiwi Islands from early Saturday morning as the tropical cyclone passes through the Van Diemen Gulf.
"However, if the tropical cyclone crosses the coast east of the Cobourg Peninsula tonight, the tropical cyclone will likely weaken before approaching Darwin, reducing the chance of gales being experienced," she said.
Gales may extend to Daly River Mouth by Saturday afternoon and further south to the WA/NT border later on Saturday or Sunday as the cyclone moves into the Timor Sea later.
A storm tide between Milikapiti and Maningrida, including the Van Diemen Gulf, is expected as the cyclone centre crosses the coast tonight.
Tides are likely to rise significantly above the normal high tide, with damaging waves and dangerous flooding predicted tonight and into Saturday morning.
Heavy rain is also expected along the north coast today, extending into the northwest Top End on Saturday.
NT Emergency Services advises residents from Milikapiti to Goulburn Island, including Croker Island to prepare for gales and heavy rain during today into this evening.
Residents should move indoors and shelter as the conditions deteriorate and stay indoors and avoid travel during the storm.
NTES also advises they stay away from beaches and immediate coastal areas as dangerous coastal flooding may occur.
Meanwhile, residents in Milikapiti to Cape Fourcroy, Point Stuart to Daly River Mouth including Darwin and Goulburn Island to Maningrida should be ready for wet and windy conditions to arrive and finalise home preparations;
"Check your family, friends and neighbours understand and are prepared," and NTES spokeswoman said.
"Move indoors and take shelter as the weather deteriorates."
For communities that remain under watch, NTES advises residents to prepare homes, yards and families for a cyclone and finalise emergency kits.
"Decide now where you will shelter - at home, with friends or family, or a public shelter, where available," the spokeswoman said.
"If you plan to leave the area, leave while it is safe to do so."
There is also a Blue Alert for people from the NT border to Mitchell Plateau, including Kununurra and Wyndham and residents there should prepare for cyclonic weather and organise an emergency kit including first aid kit, torch, portable radio, spare batteries, food and water.
Further advice on cyclone emergencies is available at www.securent.nt.gov.au
"Please ensure that friends, family and neighbours have heard and understood this message, particularly new arrivals to the area," the spokeswoman said.
UPDATE, FRIDAY: A TROPICAL Cyclone warning has now been issued for parts of the northwest Top End, including the Tiwi Islands.
As of this morning, the Bureau of Meteorology is reporting an intensifying tropical low is expected to develop into a Category 1 Tropical Cyclone during this evening.
The cyclone warning covers communities from Cape Hotham to Maningrida, including the Tiwi Islands.
"A cyclone warning means this areas may experiences gales and stronger winds within the next 24 hours, along with heavy rain," Deputy Regional Controller Warren Jackson said.
"People should stay away from beaches and coastal areas as the storm is approaching and passing due to higher than normal tides and wind-driven surf. Coastal flooding may occur in the area, which is also dangerous."
"Residents in the warning zone should remain indoors as the weather deteriorates later tonight."
Meanwhile, a cyclone watch zone remains in place from the WA/NT border to Cape Hotham and Maningrida to Milingimbi, including Darwin.
Mr Jackson said those in the Warning zone should listen for the announcement that schools could close and be prepared to collect their children
He said vehicles should be parked under solid shelter with the handbrake on and in gear and wooden or plastic outdoor furniture should go in your pool or inside with other loose items.
Mr Jackson also advised residents to draw their curtains and shut doors.
"In case you need to evacuate, pack an evacuation kit of warm clothes, essential medications, baby formula, nappies etc, valuables, important papers, photos, mementos in waterproof bags to be taken with your emergency kit," he said.
"Large or heavy valuables could be protected in a strong cupboard."
During the warning period, residents should remain indoors with their pets and stay tuned to local radio/television for further information.
For those in the cyclone watch zone, Mr Jackson said it was important to recheck yards for any loose material and tie down (or fill with water) all large, relatively light items such as boats and rubbish bins.
"Fill your vehicles' fuel tanks (and) fill Jerry cans with fuel if you have any," he said.
"Check your emergency kit and fill any water containers you may have. You should have at least 3 litres of water per person per day for at least 72 hours."
Watch zone residents should make sure household members know what the strongest part of the house is and what to do in the event of a cyclone warning or an evacuation.
To stay up to date, tune in to your local radio and/or television stations for further information and warnings and check neighbours are aware of the situation and are preparing.
Mr Jackson said the Tiwi Islands and Darwin would both begin to experience squally weather later today as the intensifying tropical low moves south.
"Motorists should keep an eye out for flash flooding and take extra care on the roads," he said.
"Please restrict your travel and only take to the roads if necessary one the weather deteriorates. Remember, if it's flooded, forget it."
Other warnings current at this time include an initial flood watch for North West Coastal Rivers and a Marine Wind Warning for gale force winds.
A list of what residents should include in their emergency kit can be found on the Northern Territory Emergency Service website: http://www.pfes.nt.gov.au/Emergency-Service/Public-safety-advice/Household-emergency-planning.aspx
For more information on the tropical low and weather warnings go to the BoM website: http://www.bom.gov.au/nt/warnings
Cyclone preparedness information is available at SecureNT: https://securent.nt.gov.au/prepare-for-an-emergency/cyclones
EARLIER: THE threat of Cyclone Marcus has forced the cancellation of a footy Grand Final, threatened to postpone an election and detour thousands of tourists before a single drop of rain has fallen.
Tiwi Island Football League officials postponed their Sunday Grand Final yesterday, while the NTFL are yet to decide on the fate of tomorrow's decider.
Hundreds of fans were destined to make the trip to Tiwi on ferries and planes, which have also been postponed.
Sealink Ferry, who were transporting about 400 people to the Tiwi Islands, have postponed their service until next weekend, while the cruise ship Queen Mary II is due to dock in Darwin Saturday morning with nearly 2700 passengers and 1500 crew.
Darwin Ports CEO Terry O'Connor said the ship was in the Torres Strait and its course of action would be determined by the overnight path of the weather system.
On Sunday, the Azamar Journey is also expected to arrive with its 690 passengers.
The Bureau of Meteorology yesterday issued a cyclone watch, with a tropical low 250km north of the Tiwi Islands set to pass through the Top End in the coming days.
The official forecast track sees the system developing into a Category 1 Tropical cyclone Friday evening.
Cyclonic conditions are expected to be brief for Darwin, easing from Saturday afternoon.
BOM senior forecaster Sally Cutter said the system may not make landfall in Darwin.
"It will first make landfall Friday night, down on the Coburg Peninsula, or the Tiwi Islands area, and then may manage to come across the Van Diemen Gulf and straight across between Darwin and the Tiwi Islands," she said.
"It may not actually make landfall again."
Ms Cutter said flooding would be a major concern, with the system building up over the Timor Sea.
"Flooding is certainly an issue with any sort of tropical cyclone or tropical low," she said.
"We do have a flood watch out for the north west rivers - we can see really large totals with the systems. with this one we are probably going to see 100-150ml, particularly around the coast - if not even up to 200ml out of this system."
Ms Cutter said the system would start moving away from the Top end from Saturday afternoon.
"Overnight Friday night, conditions building up, Saturday morning is probably going to be fairly wild and woolly around the whole of the north west Top End," she said.
"Conditions easing as we go into Sunday and then Monday should be relatively quiet again."
Northern Territory Emergency Services northern command Mark Cunnington said residents needed to prepare their properties to ensure no lose objects could be picked up and cause damage in the winds.
"Now is the time to make any final preparations around your properties. Keep an eye on the messaging and follow the advice, not the social media pundits that are making guesses," he said.
Darwinites are preparing for conditions, stocking up on provisions in case they are housebound for the next few days, with tins of food and non-perishables
Isabella Rapson has recently moved to the Top End, and has never been through a cyclone, but has plenty of food prepared for a worst-case scenario.
"I feel like I haven't prepared properly - there was a warning last week, but I think that was for Arnhem Land so I think people are taking it a bit more seriously," she said.
"(The food) will last, even if a cyclone doesn't happen."