A wild weather system creeping towards the Queensland coast is expected to develop into a tropical cyclone much more quickly than originally thought.

The Bureau of Meteorology issued its first tracking map for the tropical low on Friday afternoon, placing Cardwell and Townsville in its predicted path, with a much wider stretch of the coast on alert.

Earlier in the day, the bureau was expecting a cyclone to form on Sunday but that was later adjusted to Saturday morning.

"Everything's developing a little bit quicker," BoM meteorologist Lauren Pattie said on Friday afternoon.

The bureau warned of the chance of a category 3 cyclone forming, which would have enough intensity to damage roofs and cause power failures. Supplied

"... The atmosphere and the ocean temperatures are just very favourable for cyclone development.

"At this stage we're just monitoring anything little, anything really subtle. Subtle changes in the atmosphere make a big difference to how that system develops."

On Friday afternoon, the latest models predicted a cyclone forming on Saturday morning and heading westward before approaching the coast on Tuesday morning as a category 3 system.

But Bureau of Meteorology Queensland regional director Bruce Gunn stressed there was always uncertainty around predicting cyclones and urged residents to monitor the BoM site closely.

He said everyone from Cape Tribulation to Proserpine should be alert for landfall from any time between Sunday and early Tuesday.

"The intensity of the cyclone will hinge on how much time the system spends over the water. If the cyclone speeds up, it is likely remain at the lower end of the spectrum, but if it crosses on Monday or Tuesday there is the potential for it to intensify to severe tropical cyclone strength, category 3 or higher," he said.

Tropical cyclones of that strength were expected to cause roof and structural damage, destroying caravans and causing power failures.

Townsville Mayor Jenny Hill said she had convened the region's local disaster management group and would be meeting with it on Friday evening.

She said rainfall and flooding were the primary concern and sand would be available from Lou Litster Park.

"We've gone through these events many many times before," she said.

"At this point in time the models are showing various scenarios.

"What we say to our communities is please prepare but don't panic."

The Cairns and Hinterland Hospital and Health Service had activated its emergency operation centre.

Disaster co-ordinator Ben Ryan called on residents and patients to talk to their doctors about ensuring they had all the medicine and other medical help they needed.