More than 330,000 homes remain without power across south-east Queensland as Ex-Tropical Cyclone Alfred moves inland.

The BOM defended its integrity and asserted the accuracy of its predictions and mapping of TC Alfred. “Tropical cyclones can follow erratic paths and predicting their movement is complicated. Scientific understanding of these complex weather systems is continually developing,” said a BOM spokesman.

The prime minister has warned slower isn't "better" as Cyclone Alfred's forecast crossing of the south-east Queensland coast is pushed back later into Saturday morning.

South East Queensland and northern NSW are in it for the long haul with ex-Tropical Cyclone Alfred, forecasters have warned, with severe weather and flood warnings still in place for large parts of the east coast.

Tropical Cyclone Alfred is located 560 km east of Brisbane and the Sunshine Coast and gale force winds are expected to develop over the next 24 to 48 hours along widespread moderate to major flooding say the Bureau of Meteorology.

Residents in Queensland's south-east has been warned of life-threatening flooding that will be caused by intense rain before and after Tropical Cyclone Alfred's landfall.

As a sudden rain bomb smashed through Hervey Bay in the early hours of Sunday morning, many residents were left wondering what had happened – and why they didn’t have more notice of what was to come.

Alfred is forecast to make landfall near Brisbane, the capital of Queensland and Australia’s third largest city.

Residents in Cyclone Alfred’s danger zone have been warned they only have hours to escape, while there are fears an entire coastal city in northern NSW will be inundated with water.

The Australian Bureau of Meteorology has narrowed its watch area to Noosa to Brisbane, not including Brisbane. Follow here.

Australia’s east coast is bracing for tidal surges, intense rainfall, strong winds and flooding as a cyclone is expected to veer toward the country’s third-biggest city.

Authorities are telling residents to prepare now for wet, windy and wild weather — including potential flash flooding — from Wednesday till the weekend.