Parts of the Top End are now on cyclone watch as a tropical low develops in the Gulf of Carpentaria.
According to the Bureau of Meteorology (BOM), the low is embedded within a monsoon trough and is expected to intensify this afternoon and overnight.
As a result, the BOM has issued a tropical cyclone watch for communities along the Top End's east coast from Groote Eylandt to the Queensland border.
"We would expect those communities to potentially have those impacts from Tuesday morning but not during tomorrow," the BOM's Shenagh Gamble said.
"There is uncertainty around the track of the system, however, the conditions are favourable for it to develop into a tropical cyclone, particularly if it stays towards the north of the Gulf of Carpentaria."
If it does, it will be called Topical Cyclone Herman.
Ms Gamble said even if the low doesn't reach cyclone strength, it is still expected to bring strong winds, heavy rainfalls, and potential flash flooding to communities on Groote Eylandt, as well as Numbulwar.
Damaging winds of up to 70kmh, with gusts of up to 90kmh, are expected to hit the region within 48 hours.
Regional Controller for the NT's northern region, Assistant Commissioner Travis Wurst, advised residents to have their cyclone kits prepared with sufficient food and water.
"We're not asking for any alarm here, we’re just trying to be prepared and give early advice to those communities so they are ready," he said.
He said emergency committees on the ground in Groote Eylandt, Numbulwar, Ngukurr and Borroloola were making preparations.
"If it does stay in the north and it does develop, we’re ready."
Flood watch in place across the Top End
A flood watch has also been issued for a large part of the Top End, with widespread falls of between 40mm to 60mm already being recorded.
Ms Gamble said rainfalls of about 200mm per day could be seen in the areas around the weather system.
In a statement, the BOM has warned that "significant rises" in creeks and steams are expected to impact many roads across the Top End over the rest of the weekend and into early next week.
"Some communities and homesteads may become isolated," the BOM said.
"Check road conditions before travelling."
A severe surf warning has also been issued from the the south-east Arnhem coast, to Groote Eylandt and as far south as the Queensland border.
