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.

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.

The Bureau of Meteorology is now predicting Cyclone Alfred to cross the coast Friday night or early Saturday morning, most likely between Noosa and Coolangatta. Take a look back at our live blog.

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.

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.

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.

Millions of residents along Australia’s eastern coast are bracing for the arrival of a very slow-moving storm, the most southerly tropical cyclone to threaten the region in more than 50 years.

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.

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.

The Bureau of Meteorology has been accused of failing to warn Hervey Bay of severe storms that dumped more than 300mm of rain on the coastal community, causing flash flooding and a string of swiftwater rescues.

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

Credit: BoM During Wednesday, Alfred picked up speed and was moving towards the coast at 11km/h. By nightfall, Alfred had slowed to 7km/h and was 365 kilometres east of Brisbane and moving northwest.