Authorities in Australia have begun evacuations for the 1,600 residents of Groote Eylandt, an island in the Gulf of Carpentaria, as Tropical Cyclone Trevor approaches.

The severe storm spent most of Wednesday crossing Cape York, having made landfall on Tuesday evening near Lockhart River on the east coast.

It brought down trees, electricity poles and fences, registering wind gusts of up to 133 kilometres per hour and a rainfall collection of 333mm.

Trevor’s wind strength was the equivalent of a Category-2 hurricane at first landfall. It left the Cape York Peninsula as a much-weakened storm, but near the town of Aurukun it met the warm feed waters of the Gulf of Carpentaria and started strengthening again.

Todd Smith, the BoM’s Northern Territory manager, said the weather system would be severe and residents needed to be prepared.

Trevor is expected to make land again on Saturday, somewhere between Groote Eylandt and Borroloola.

The cyclone is expected to strengthen to a “catastrophic” Category 4 as it passes Groote Eylandt, registering winds of a steady 210km/h, with gusts to 260km/h.

Ross McDonald, an environmental officer at Anindilyakwa Land Council, said cyclones were not uncommon in the area but had never seen Groote Eylandt evacuated.

“I’ve been here for 15 years and … we have a lot of cyclones … but this is definitely the one we’ve had the most concern about,” he said.

“And that being the case a lot of the properties aren’t built for Category-4 cyclones.”

Even as a young storm in the Coral Sea, Trevor generated four-metre waves. With three days winding up over the Gulf of Carpentaria, it could generate much larger waves and a significant storm surge – a general rising of the sea level in advance of the cyclone.