The Bureau of Meterology has 'watch' and 'warning' zones for many Gulf of Carpentaria communities as dangerous conditions, such as very destructive winds, widespread heavy rainfall and a very dangerous storm tide threaten the area due to Severe Tropical Cyclone Trevor.
Severe Tropical Cyclone Veronica is forecast to cross the Pilbara coast on Sunday also bringing with it very destructive winds and widespread heavy rainfall.
Cyclone Trevor a category 4
Emergency services say over 2,000 spent the night in evacuation shelters in Darwin and Katherine.
BOM says Severe Tropical Cyclone Trevor was making landfall over the southwestern Gulf of Carpentaria Coast, about 90 kilometres east of Borroloola. The system is moving southwest and is expected to slowly weaken as it tracks inland today, and may persist as a cyclone for about 24 hours after making landfall.
"As Trevor moves inland and weakens into a tropical low, western parts of the Carpentaria, southern and western parts of the Barkly Districts, including Tennant Creek, are expected to experience damaging to locally destructive winds and heavy rainfall that may lead to flash flooding from Saturday night and into Sunday." its latest situation report said.

A satellite photo shows the fury of Cyclone Trevor as it approaches Top End communities. (AAP) Source: AAP
Head of NT Emergency Services Jason Collins said anyone remaining in Trevor's path needs to have supplies to last at least three days, take shelter and stay away from waterways.
"Turn around, don't drown, we may not be there to save you," he told reporters in Darwin late on Friday.
Current predictions suggest the cyclone will move more than 400 kilometres inland before it weakens to a tropical storm.
Trevor left behind a trail of damage in Queensland's Cape York Peninsula earlier this week, uprooting trees, causing flooding and roof damage, closing schools and roads, and knocking out power supplies.
Anxious residents worried about their homes and pets were evacuated by road and on Australia Defence Force cargo planes from Borroloola, Numbulwar, Groote Eylandt and other Indigenous communities.
"We've used buses, vehicles, ferries, planes, helicopters and anything else in between we can get out hands on," police regional controller Travis Wurst said.
It is the largest evacuation prior to a cyclone in the territory's history and largest type of any evacuation since Cyclone Tracy in 1974.
Cyclone Veronica approaches WA
Meanwhile, supermarkets in Western Australia's north are running out of supplies as people continue to prepare for Tropical Cyclone Veronica.
Tropical Cyclone Veronica remains a category four system as it travels closer to Western Australia's northern coast but may temporarily intensify to a category five.
The Bureau of Meteorology says the Pilbara region is likely to be impacted from late Saturday afternoon and on Sunday.
"While the cyclone may weaken before reaching the coast, a severe coastal impact is likely."
Pictures circulating on social media show supermarket shelves in the region bare.

Many supermarket shelves in the region are empty as residents prepare for Cyclone Veronica Source: Twitter: @nat_forrest
Gales with gusts to 100km/h may develop between Pardoo and Mardie on Friday evening, and may extend farther east to Wallal Downs, farther west to Onslow and extend to inland areas including Pannawonica and Marble Bar later on Saturday.
Destructive winds with gusts exceeding 125km/h are forecast to develop along the coast between Dampier and Pardoo later on Saturday.
The severe weather coincides with World Meteorological Day today (Saturday) which is marked each year on 23 March and highlights the key role meteorological agencies play, such as the Bureau, in helping to protect community.