Top end residents have been warned that authorities cannot guarantee their safety as Cyclone Lam continues to intensify as it travels west.
As of 5pm, the storm remained a Category 3, with winds reaching 165km/h as it hovers halfway between Nhulunbuy and Elcho Island.
Public shelters are now open from Elcho Island to Cape Shield, including Nhulunbuy.
On Elcho Island, 101 people are sheltering at Shepherdson College.
Thirteen people are sheltering at the Yirrkala Laynhapuy Homelands Centre, which can hold 200, and 85 people are sheltering at Gove District Hospital, which can hold 300.
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Other shelters are being prepared as they fill.
By late Wednesday, the hospital was housing about 60 Yolngu people from the smaller communities of Wallaby Beach and Ski Beach.
"We got here last night," said Janet Yunupingu. "It's okay, we're fine. We don't know how long we'll be here for."
About a third of the occupants are children, who ignored the dark skies and tore playfully around the hospital grounds.
Boredom was beginning to set in, and as conditions seemed to ease, a few families headed home.
"People are actually starting to leave," said Troy Harris, the Senior Constable overseeing the cyclone shelter.
The Bureau of Meteorology model forecasts that Cyclone Lam will continue travelling west, intensifying to a Category 4 before turning south to make landfall later on Thursday.
If it crossed the coast at the same time as the high tide, residents could be vulnerable to severe and dangerous flooding and damaging waves.
People must remember that "authorities cannot guarantee their safety in any circumstances", said Commander Bruce Porter from the NT Police.
Reporters, extra police, some Nhulunbuy residents and local member Lynne Walker were all thwarted at the Darwin Airport early on Wednesday morning as it was announced the Gove Airport had been closed.
Ms Walker said residents had food and power, and were so far in good spirits.
"Some people are a little anxious about it, there are people living there long term who say this is part and parcel of living in coastal areas of the top end at this time of year," she said.
But the storm hasn't been bad news for everyone: surfers took to the waters at Yirrkala on Tuesday, hoping the crocodiles were sheltering as they took advantage of a rare swell.
The BOM will continue to issue hourly advice.
