A Cyclone Warnings has now been issued for Darwin itself:
"Darwin awaits cyclone Monica's arrival
Monday, 24 April 2006. 07:48 (AEDT)
In for bad weather: Monica is expected to stay a category 5 cyclone.
The Bureau of Meteorology has issued a cyclone warning for Darwin as cyclone Monica moves closer.
A warning is now current for coastal and island communities between Nhulunbuy and the Daly River Mouth, including Darwin, Jabiru and the Cobourg Peninsula.
It means gale force winds could hit those areas within the next 24 hours.
The category 5 system is continuing to move west and the weather bureau says at this stage, the Cobourg Peninsula looks the most likely region to be hit by the eye of the cyclone.
Senior forecaster Graham King expects Monica will remain a category 5 system for most of the day.
"It's just far enough offshore at the moment that the really destructive winds are offshore but as it comes in towards the Cobourg Peninsula all those islands up there ... have the potential to get some pretty nasty weather," Mr King said.
Monica passed over Elcho Island this morning with no damage to buildings and no injuries.
Emergency services personnel at Nhulunbuy in north-east Arnhem Land have closed the town's cyclone shelter.
About 9:00pm ACST yesterday emergency crews sounded sirens in Nhulunbuy telling people they could leave their shelters.
Senior Sergeant Tony Fuller says some people had been in Nhulunbuy's cyclone shelter for 24 hours and it was time to let them go home.
"I know a lot of people were fairly bored especially in the shelters [and] we had some issues with people running out of food," he said.
Strong winds brought down several trees in the town last night but police say there has been no damage to houses.
Nhulunbuy police are still keeping an eye on people on two catamarans on the Wessel Island."
(The ABC NT news website is http://www.abc.net.au/nt/news/default.htm