Authorities are on alert for the arrival of the system, with forecasters saying there is still a moderate chance it could strengthen into a cyclone.

The low in the Coral Sea is about 1300km northeast of the Sunshine Coast.

Bureau of Meteorology forecaster Lauren Pattie said it was expected to track to the southwest, closer to the coastline, in the coming days.

She said it would cause dangerous surf conditions before it tracked back out to sea.

While high tides could cause inundation in low-lying areas prone to flooding, Ms Pattie said heavy rainfall was not that likely because the system would remain "well offshore".

Its development comes after three weeks of devastating weather in other parts of the state.

Emergency Services Minister Craig Crawford is in the flood-ravaged north, and says major roads have been severely damaged.

He said it would take weeks to determine the final repair bill but it could amount to tens of millions of dollars.

There are concerns too that flood waters could spread the devastating soil disease Panama TR4 to banana farms throughout the Tully Valley after an outbreak on one property was detected last month.

Mr Crawford said the wild weather had taken a toll on communities, including Yam Island in the Torres Strait, north and far north Queensland, and swathes of the state's western interior.

"It's quite evident - just the sheer size of this weather system and the storms and floods that have occurred," he told reporters in Innisfail.

After meeting with anxious Tully banana growers, and visiting devastated Ingham, he'll head west to Mount Isa on Wednesday to talk to mayors still dealing with inland flooding.

"We've still got towns and communities cut off," Mr Crawford said.

"There's barely a few parts of Queensland that haven't been touched by storm activity in the last two to three weeks."

The Bruce Highway north and south of Ingham reopened on Monday, but lower speed limits are in force on some damaged stretches.

In the far north, engineers are investigating a large crack that has opened up on the Palmerston Highway. There have also been landslips on that highway, as well as the Gillies Range Road and Kennedy Highway.

And the Burke Developmental Road, north of Normanton, is still under a significant amount of water and is expected to be closed for some time.