Ex-Tropical Cyclone Alfred has drenched south-east Queensland bringing flash flooding to Brisbane and the Gold Coast.

Rainfalls of up to 80 millimetres are forecast by the BOM in Brisbane and the Sunshine Coast, while 50mm could fall in Grafton, where the Clarence River is nearing major flood levels.

Significant damage and power outages are possible in the densely populated region of Queensland, where tropical cyclones impacts are not uncommon but direct landfalls are.

Tropical Cyclone Alfred was 65 kilometres north northeast of Brisbane and 45 kilometres south southeast of Maroochydore at 6am this morning.

Hundreds of thousands of people in Australia's Queensland state were without power on Sunday after Alfred, a downgraded tropical cyclone, brought damaging winds and heavy rains, sparking flood warnings.

Tropical Cyclone Alfred weakened into a tropical low Saturday as it neared Brisbane, Australia, bringing heavy rain and flooding risks to the region, according to officials. Initially expected to make landfall as the first cyclone to strike southeast Queensland since 1974, Alfred's winds dropped to under 39 mph (63 kph) as it shifted inland.

Cyclone Alfred - which has been downgraded from a cyclone to a tropical low - has caused flooding, damage to buildings and left thousands without power across the eastern coast of Australia. Millions of people across Queensland and north New South Wales have been affected.

Officials say flooding rains will continue for days to lash a region of the Australian east coast even though it avoided its first tropical cyclone in 51 years

Ex-tropical cyclone Alfred lingered off the south-east Australian coast on Saturday and forecasters said Brisbane is likely to miss the worst of the storm, a relief for millions of residents in the region who have been staying indoors.

A slow-moving tropical storm crossed islands off Australia’s heavily populated eastern coast late Friday, lashing coastal suburbs with destructive winds and dumping heavy rain across the region.