Tourists and coastal residents have been evacuating parts of the Great Barrier Reef as a powerful cyclone intensifies in the Coral Sea and makes its way towards Australia's northeast.

Cyclone Ita is forecast to make landfall tomorrow north of the tropical city of Cairns, bringing with it the possibility of widespread flooding and damage, emergency officials said.

Wind gusts of up to 280km/h are forecast, bringing with them torrential rain, according to the Australian Bureau of Meteorology.

"The sea is likely to rise steadily up to a level which will be significantly above the normal tide, with damaging waves, strong currents and flooding of low-lying areas extending some way inland," the bureau said.

The storm was still classified as a tropical depression when it barrelled across the Solomon Islands late last week. It killed at least 23 people near the capital, Honiara, according to the United Nations.

In Australia, rescue helicopters have been sent to find and warn people in remote regions about the approaching storm.

Campgrounds have been ordered to close and islands near the coast evacuated.

A Great Barrier Reef resort located on Lizard Island 240km north of Cairns confirmed it had evacuated all its guests.

The storm's projected course should take it across a sparsely populated section of Queensland state.

Queensland Premier Campbell Newman said up to 9,000 people could be affected by the cyclone, including residents and visitors in Port Douglas, a favourite holiday spot for many international tourists.