Australia Weather News

Ex-Cyclone Debbie is causing monsoonal rain and major flooding across central Queensland, with the deluge set to hit Brisbane on Thursday.

The capital and surrounds are expected to get more than a month's worth of rain, before the low pressure system moves offshore on Friday.

The Bureau of Meteorology (BOM) said rivers from Ayr in north Queensland to the NSW border would experience some major flooding, however there would not be enough consistent rain to have a repeat of the 2011 Brisbane flood disaster.

In 24 hours, 646mm fell on the Clarke Ranges, north-west of Mackay. That was on top of 340mm on Monday.

More than a metre fell over Mt William over two days.

Some coastal communities had up to 400mm, and Gladstone and Bundaberg about 100mm.

Over the next day, Moranbah, Clermont, Emerald, Springsure, Rolleston, and the adjacent inland could get between 150mm to 250mm.

Streets in some parts of Mackay are flooding after this morning's high tide and continuing heavy rain, and there is extensive flash flooding.

Queensland Fire and Emergency Services Commissioner Katarina Carrollsaid two people have already had their cars rescued from floodwaters, one in Mackay and another in Proserpine.

She told people to stay off the roads.

"There is flash flooding and we're expecting more of it," she said.

Bowen's Don River has broken its banks.

A moderate flood warning is current for the Don, Proserpine and Lower Burdekin rivers.

There is a major flood warning for the Pioneer River, around Mirani and the Connors and Isaac rivers.

An initial minor flood warning is current for the Kolan River and Boyne and Baffle Creeks and other catchments at flood risk include the Warrego, Condamine-Balonne, Moonie, Weir, Macintyre, Calliope, Cherwell-Burrum, Burnett, Mary, Noosa, Maroochy, Mooloolah, tributaries of the lower Brisbane, and Logan and Albert.

The BOM issued a severe thunderstorm warning this afternoon for parts of north Queensland including Bowen, Townsville, St Lawrence, Sarina, Ayr and Alva Beach.

It said the storms were likely to produce damaging winds and heavy rainfall that might lead to flash flooding in the warning area over the next several hours.

No chance of major Brisbane River flooding

BOM forecaster David Crock said ex-Cyclone Debbie was continuing to weaken and would move fairly quickly to the south-east by Thursday.

Brisbane and surrounds could receive up to 200mm in 24 hours, with the worst of it on Thursday night. The monthly March average is 138mm.

The falls will not be enough for a repeat of the 2011 Brisbane River flood.

"We have had quite a dry summer, so there isn't a build-up of moisture in the catchments to allow that," he said.

"It is a quite a different set-up.

"We don't have an upper trough which sat above us [in 2010-2011] for a couple of days which provided a lot of rain.

"This one is quick moving and will clear up by the weekend, there will not be a repeat of the 2011 weather event."

Southern dams released ahead of deluge

Water Supply Minister Mark Bailey said the Wivenhoe and Somerset dams would be released in preparation. They are currently at 74 per cent and 68 per cent capacity.

The tropical low will move offshore on Friday, according to forecasters.

An upper trough will move in over the top, intensifying the system in the Tasman Sea, but it will not reform into a cyclone.

The system could, however, generate gusts of up to 100kph and dangerous surf.