Police say tourists and residents on Heron Island, off Rockhampton, and Lady Elliot Island, off Gladstone, will be evacuated over the next two days.
In Rockhampton, the local disaster management committee is meeting to ensure the region is prepared.
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The weather bureau expects Ului, currently a category four cyclone, to cross the coast somewhere between Bowen and Gladstone on Saturday or Sunday.
It says the cyclone could bring swells of between eight and 10 metres, but that will depend on exactly where it hits and its intensity.
Even though the cyclone is expected to hit well north of Brisbane, the bureau says coastal communities in the southeast can expect dangerous surf conditions.
Island resorts closed
Acting police inspector Julia Cook said ferries would bring 260 residents and visitors from Heron Island, and 70 people from Lady Elliot Island, to the mainland over the next two days.
"It's unknown what will occur, however for safety... Lady Elliot and Heron Island, they will commence evacuation today," she told the ABC.
She said any evacuation of the islands needed to be done early to avoid people being trapped by rough seas.
The Heron Island Resort said on its website that it would close as a precaution until Saturday, when the situation would be reassessed.
Comment was being sought from the Lady Elliot Island Eco Resort.
Rockhampton Mayor Brad Carter said the disaster management committee was meeting on Wednesday morning to ensure communities were prepared.
Conditions 'unpredictable'
He said a cyclone rated as category three or stronger could cause big problems.
"One of the issues we have to look at is tidal surge - the impact of the rising sea level in conjunction with wave activity and cyclonic activity," he told the ABC.
"A number of parts of our coastline are very exposed."
Bureau of Meteorology forecaster Michelle Berry said there was still a significant element of unpredictability about the cyclone and its path.
But she added: "On current predictions the most likely scenario is that it will cross the central Queensland coast somewhere between Bowen and Gladstone sometime over the weekend," she said.
She said the cyclone was expected to remain well off shore for the next two days, and on Friday was expected to take a more west-southwest track, moving closer to the coast.
Dangerous surf warning
She said swells of at least four to six metres were expected but they could be much higher.
"It depends on the intensity of the system, and also where it hits because of the slope of the coastline and also the interaction with the reef," she said.
"But it's possible we could see swells of eight to 10 metres."
Dangerous conditions are also expected in the southeast.
"Even though the cyclone is to the north, we're still expecting dangerous surf conditions due to the large swell radiating out from the cyclone," Ms Berry said.
At 4am (AEST) on Wednesday, Ului was 1,240km northeast of Mackay and 1,370km east of Cooktown, moving south at about 4km/h.
