More severe weather forecast for NT

More severe weather is expected to hit some parts of the Northern Territory as ex-Tropical Cyclone Nathan continues to impact the Top End.

The Bureau of Meteorology issued the warning for possible heavy rain in the southwestern Top End early Thursday morning.

It said the storm system was off the west coast and was moving west into the Timor Sea, away from the Northern Territory.

"Heavy rain which may lead to flash flooding is forecast for parts of the Daly, Gregory and western Carpentaria forecast districts," BoM said in a statement.

It said locations that could be affected include Bradshaw, Dorisvale, Douglas River, Nauiyu, Katherine, Katherine Airport, Delamere, Newry, Timber Creek and Victoria River Downs.

The weather bureau is urging people in affected areas to secure loose objects and seek shelter when conditions deteriorate.

All 427 residents of the remote Goulburn Island, 300km east of Darwin, returned home Wednesday morning after spending two nights in an emergency cyclone shelter at Darwin Showgrounds as the cyclone menaced the area.