A tropical low over far north Queensland is expected to intensify into a cyclone and head south.
The strengthening weather system is sitting over Cape York Peninsula and is forecast develop throughout Friday, the Bureau of Meteorology says.
The system was about 125km west of Weipa in the Gulf of Carpentaria and extends north across the peninsula.
The low has a greater than 50 per cent chance of becoming a cyclone by Saturday, with far northern communities warned to expect heavy rain that could cause flash flooding during Friday.
Wind gusts of 90km/h are possible.
Communities from just north of Cairns to Pormpuraaw and further north, on the Gulf of Carpentaria, are under a severe weather warning, along with the Torres Strait.
A flood watch is current for major catchments in the region, with 6-hour rainfall totals in excess of 150mm possible.