Two tropical cyclones are gaining strength near northern Australia and could both make landfall as category four systems this weekend.

Tropical Cyclone Trevor moved off the west coast of Cape York Peninsula on Wednesday night. The category one tropical cyclone is expected to rapidly intensify as it moves over the Gulf during the next 24 hours, possibly reaching category four strength on Friday.

Trevor is tipped to make landfall somewhere along the Northern Territory's Roper Groote Coast this weekend as a category four severe tropical cyclone. At this stage, this could happen anywhere between Groote Eylandt and the Queensland border, most likely on Saturday.

Image: Two tropical cyclones were concurrently spinning over Australian waters on Thursday.

Meanwhile, Severe Tropical Cyclone Veronica became a category four tropical cyclone on Thursday morning, just over 24 hours after it formed to the north of Broome.

At 8am WST on Wednesday, Veronica was located less than 500km to the north of Port Hedland, with wind speeds estimated to be reaching 185km/h near its core. This makes Veronica the strongest tropical cyclone  in Australian waters so far this season.

Severe Tropical Cyclone Veronica is expected to become a scale-topping category five system during the next 24 hours as it slowly moves towards Australia's northwest coast.

Veronica should approach Western Australia's Pilbara coast during the next two days and could make landfall somewhere between Pardoo and Mardie this weekend.

At this stage, Veronica and Trevor are both forecast to be at least category four tropical cyclones on Friday and Saturday. This would be the first time two cyclones of this strength have existed concurrently in Australian waters for four years.

Visit http://www.bom.gov.au/cyclone for the latest cyclone advisories and track maps.