Australia Weather News

South-east Queensland residents are on alert as a massive weather system that caused widespread flooding in the outback is expected to heap more rain on the already sodden region as it moves south.

The Bureau of Meteorology (BOM) is predicting some parts could see between 50 and 100 millimetres of rain on Saturday, with the chance some elevated and coastal areas could see even more.

While it's well short of the kinds of rainfall totals experienced only a few weeks ago during ex-Tropical Cyclone Alfred, BOM said rivers and creeks could "respond rapidly" to even moderate rain.

"Catchments are saturated and there's very little wiggle room to absorb any further moisture," senior forecaster Felim Hanniffy said.

"So, a watch point will be that creek and river systems are likely to respond as well, with the potential for riverine and localised flash flooding."

Mr Hanniffy said the heaviest rain was likely throughout Saturday, with falls set to ease by Sunday.

Not including yesterday's rain, the Brisbane CBD had registered 508mm of rainfall for March — well above the month's average of 140mm.

Further south, the Gold Coast also dramatically exceeded its average rainfall for March due to ex-Tropical Cyclone Alfred, with just under 500mm registered in the seaway gauge.

The Gold Coast council has opened three sandbagging stations over Thursday and Friday in preparation for the wet weather.

Yesterday Mayor Tom Tate said he was hopeful that if the rain eased by Sunday, the region would be spared the kind of flooding and damage it saw earlier this month.

However, the BOM predicted strong onshore winds, hazardous surf and significant swells along the coast — potentially eroding beaches that were smashed by massive ocean swells generated by Alfred's approach.

Mr Tate said repairs on the beaches would be paused until the rain eased.

"I can't have heavy equipment on sand that's soft, sodden," he said.

"It's going to cost us a couple of days."

But he remained "so confident" beach works would be done by the Easter long weekend, renewing his promise to buy beer for everyone on the Gold Coast if he didn't meet the deadline.

Dams spilling

SEQ Water's Flood Operations Centre has been running 24/7 the past seven days, general manager of service continuity Matt McCahon said.

He said up to 60 millimetres was expected within the Wivenhoe catchment area today, and up to 100 millimetres could fall across the North Pine and Somerset catchments over the weekend.

SEQ Water has begun releasing water from North Pine and Somerset dams, which sit at 53.5 and 79.7 per cent full respectively.

The region's largest dam, Wivenhoe, is currently at 89.6 per cent capacity.

"With the anticipated rainfall moving forward, we're expecting that we might have to make some controlled gated releases, very low level, out of Wivenhoe and North Pine dams into the weekend," Mr McCahon said.

"That will all be very dependent on the rainfall."

Twenty of SEQ Water's 23 ungated dams have been spilling since Alfred passed over the south-east, he said.