Top End residents hope to launch into clean-up mode after enduring a rough night of damaging winds and heavy rain as tropical cyclone Fina swept by.

Households in Darwin and surrounds were told by emergency authorities on Friday to stay in their homes or emergency shelters until given the all-clear.

Category-three Fina brought destructive winds and heavy downpours to remote Tiwi Islands communities, then Darwin and surrounds on Saturday and into Sunday.

Forecasters had Fina tracking just north of Darwin.

Northern Territory Police incident controller Kirsten Engels on Friday urged residents to stay at home, but the sweeping sheets of rain on the streets and high wind gusts kept pretty much everyone indoors anyway.

Emergency shelters were open in Darwin, nearby Palmerston and adjacent rural areas, with people urged to bring their own bedding and food.

Part of the roof at the Royal Darwin Hospital collapsed on Saturday but no one was hurt, NT Police incident controller Emma Carter told ABC Radio Darwin.

“The reports are that a small section of ceiling approximately four square metres has collapsed on the first floor,” she said.

Bureau of Meteorology NT manager Shenagh Gamble said Fina was a “small and intense” system and residents of Darwin and surrounds could expect conditions to worsen quickly.

“So as we approach this evening and the sun goes down, conditions are going to deteriorate significantly,” she said in a video update on Friday.

Gamble said conditions would ease considerably from Sunday morning.

Power cuts and trees down were reported on Friday and more of the same is expected when residents emerge when the all-clear is given on Sunday.

As householders tidy their front and back yards, repair crews will work to restore power and clean-up crews will clear the roads of debris.

Senior meteorologist Dean Narramore said on Friday that Darwin could experience winds of up to 120km/h, “easily enough to cause property damage and bring down trees and powerlines”.

Cyclone Tracy was the most devastating system to hit Darwin, killing 66 people on Christmas Day, 1974.

—AAP