The NT is bracing for more heavy rain and flooding as Tropical Cyclone Fina closes in and possibly strengthens to category 3.

A Bureau of Meteorology update this afternoon said the category 1 storm has sustained wind speeds near the centre of 85km/h, with gusts to 120km/h.

Fina is affecting the Cobourg Peninsula, extending to other parts of the northeast Top End today.

The bureau’s warning zone covers the Tiwi Islands, Dundee Beach to Warruwi, and inland to Batchelor. It includes Darwin, the Cobourg Peninsula, Minjilang and Gunbalanya, plus Pirlangimpi, Milikapiti and Wurrumiyanga.

“It is very close to the Northern Territory coast, which means we can actually see the bands of rain on our radar network … These bands of rain have already brought over 200mm of wet weather to parts of this exposed coastline,” meteorologist Adam Hines said.

“And in the coming hours, that rain is only going to get more extensive and impact new areas.”  

The storm is projected to follow a southwest trajectory and to strengthen from category 1 to category 2 before the end of today.

Mr Hines says tomorrow is critical because the storm “is going to cross the tip of the Cobourg Peninsula and move southwestwards through the Van Diemen Gulf, past the Tiwi Islands, get somewhere very near Darwin ... about 10pm on Saturday evening”.

Mr Hines says Fina is likely to be at category 2 as it passes Darwin and may strengthen to category 3 as it approaches northern WA.

“How might that look in terms of the weather we expect this track to bring? Well, the two key words are windy and wet. Those winds are really going to race around that category 2 tropical cyclone, including as it approaches and moves past Darwin.

“There will be extensive, heavy, persistent rainfall across parts of the north and west of the NT once again, including that Darwin area.

“Many regions could see 200mm-300mm of rain, and some spots could even see more than that. That is likely to lead to significant flooding.”