A man has died in floodwaters southwest of Brisbane, as Queensland braces for more severe weather, with NSW also expected to cop thunderstorms and big downpours.
The 71-year-old man's car was found submerged in waters at Greenbank, near Logan, where more than 100mm of rain fell in an hour on Wednesday night.
His body was found near the car early Thursday morning.
Acting Commissioner Steve Gollschewski said police were investigating the man's death.
"Our investigation is underway as to what the circumstances were," he said.
"Early days on that yet but clearly an absolutely tragic circumstance."
Mr Gollschewski said emergency services had to rescue people who had driven into floodwaters in the same area.
He said the SES had received 12 calls for help across the region overnight.
A severe weather warning has been issued in Queensland for the Central West, Marranoa and Warrego regions, with 91mm recorded at Old Tambo Road, north of Charleville, in six hours on Thursday morning.
The Bureau of Meteorology's Angus Hines said more warnings could be issued as thunderstorms moved through much of the state's south.
"The most vigorous activity is generally over that Marranoa and Warrego region but potentially a little bit later today that could move somewhere else," he told AAP.
"The primary threat is going to be heavy rainfall, much like it was last night; localised pockets of very heavy rainfall."
Major flooding is being predicted along the Bremer River on Thursday morning, where the bureau says water levels have already risen sharply following Wednesday night's heavy rainfall.
Moderate flooding is also possible in parts of the southern inland and southwest of Queensland including the Condamine, McIntyre, Weir, Warrego and Moonie Rivers.
For residents near the Moonie and Condamine rivers it marks just a few months since river levels rose, flooding homes in January.
The weather system is expected to loom over NSW in the coming days, bringing heavy rain, flash-flooding and strong winds.
The bureau warned residents of the Hunter, Sydney, Blue Mountains and Illawarra to prepare for the severe weather from Friday.
Rainfall totals of up to 300mm in 24 hours are possible in the Illawarra, while up to 200mm could fall between the Blue Mountains and Moruya.
Damaging winds are also being forecast, with gusts up to 90km/h possible along the coast south of Sydney.
A flood watch is in place for the Mid North Coast, Wollombi Brook, Sydney region, South Coast and parts of the north west.
The Hawkesbury Nepean River could rise to major flood levels from late Friday.
Conditions are predicted to ease by Saturday afternoon.
Australian Associated Press
