More than five people have made it to safety after their cars became stuck in rising floodwaters across south-east Queensland, with authorities warning of possible flash flood across the region.

Queensland Ambulance Service said multiple people escaped from their vehicles on Bechmere Road at Caboolture, north of Brisbane, while a woman in her 50s made it to safety after her car became stuck on Imbil Island Road, Imbil, on Wednesday night.

A woman in her 30 has already died in floods near Mackay, in north Queensland, after unseasonal May rainfall up to 10 times the monthly average pummelled large parts of the state triggering flooding.

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The Bureau of Meteorology said downpours of up to 177 millimetres in some areas had hit the south-east of the state in the 24 hours to 4am on Thursday.

It has warned major flooding is possible along Laidley Creek, with moderate flood warnings on the Bremer, Lockyer and Brisbane rivers on Thursday and Friday.

Queensland Fire and Emergency Service State Co-ordinator James Haig warned people to be alert as water levels would rise quickly in already saturated catchments.

“We’ll have water across roads, you can see that’s already happened in a number of places in the southeast and across the state,” he told ABC Radio on Thursday morning.

“We really ask people to pay attention to that. If it’s flooded, forget it.

“The consequences as we’ve seen in the last event, and this one, can be absolutely tragic, so please don’t get tempted to try and enter it.

“Don’t think you can judge it; the consequences are disastrous.”

Forecasters said Laidley Creek could reach a major flood level of 7.1 metres late on Thursday morning with major flooding. Moderate flooding is expected along the Bremer River at Rosewood, Five Mile Bridge and Walloon.

Moderate flooding is also expected along Warrill Creek at Harrisville and Amberley, with minor flooding already taking place along the Upper Brisbane River and major flooding on the Stanley River at Woodford.

The BOM warned further heavy rainfall in the next 24-48 hours could trigger major flooding.

The Mary River is expected to break its banks at Gympie, north of Brisbane, potentially reaching a moderate flood level of 12 metres on Thursday afternoon. It would be the third flood to hit the city this year.

Minor to moderate flooding is expected downstream at Miva and Tiaro, but the river will remain below a minor level at Maryborough into Friday.

About 100 kilometres west of Mary River, Cooper Creek has broken its banks and expected to remain at moderate flood level, while 330 kilometres north-west Eyre Creek is flooding at Bedourie.

The Flinders River is flooding at Richmond, about halfway between Townsville and Mount Isa, while the Burdekin River is expected to peak close to 7.5 metres at Teamas, south of Townsville.

The unseasonal deluge is Queensland’s fifth deadly flood since December, which scientists have put down to a second La Nina weather pattern in two years.

-AAP