Destructive winds and heavy rain are expected to lash coastal north Queensland areas over the weekend as a possible cyclone tracks towards the mainland, forecasters say.

A strengthening tropical low, which was about 560km northeast of Cairns on Friday, is expected to form into a cyclone in the Coral Sea on Sunday.

The Bureau of Meteorology has issued a cyclone watch warning for coastal areas from Cairns to Mackay.

There is a 50 per cent chance the storm will make landfall as a cyclone on Sunday or Monday, but forecasters have warned it's too early to say exactly where it will hit or if it will cross the coast.

"It's going to get close," BOM forecaster Dean Narramore said.

"A lot of the models get it right to the coast and then the steering influences changes just as it's getting to the coast and then it moves back away."

Early predictions show the storm making landfall near Bowen, between Townsville and Mackay.

But whether the system makes landfall or not, residents between Cairns and Mackay can expect strong winds and areas between Cooktown and Mackay could see heavy rain over the weekend.

Areas between Townsville and Mackay could see destructive winds and up to 200mm of rain.

"If it's just going to get close to the coast and stay there for a while that can be just as bad (as if it made landfall)," Mr Narramore said.

"You're going to get really bad conditions along the coast for up to a day or so."

If it forms into a cyclone it will be called Gillian and will be the fourth to hit the state this wet season after cyclones Dylan, Edna and Fletcher.

AAP