Ex-Tropical Cyclone Winston could reform and head towards the Queensland coast, the Bureau of Meteorology (BoM) says, as massive swells close Gold Coast beaches
The system, which is about 1,000 kilometres east of Brisbane and moving west, is then due to travel north-west into the Coral Sea.
Forecaster Jess Carey said there was a "slight possibility" it would intensify into a weak category one cyclone.
"It's moving into a body of water that is slightly warmer, so it's moving into more favourable territory," he said.
"The effects are going to be the same whether it's a category one cyclone or an ex-tropical cyclone: big seas, big waves and pretty significant high tides as well."
Mr Carey said the system would "park itself" about 200 to 400 kilometres off the coast before moving to the north-west, parallel with the coast.
"As it moves to the north it'll die away quite significantly," he said.
'Head for the hills'
Swell up to four metres is expected and high tides could exceed the highest of the year.
Gold Coast acting chief lifeguard Chris Maynard said the severe conditions would worsen Friday night and Saturday.
All Gold Coast beaches north of Burleigh were closed on Friday and the Gold Coast's 41 beaches are expected to be closed on Saturday.
"The swell is building as we speak and throughout the day it will gradually get bigger and leading into four-metre ocean swells on Saturday," Mr Maynard said.
Gold Coast Mayor Tom Tate has told locals and tourists to head for the hills and avoid the water.
"The beaches will be closed this weekend and it's a wonderful time to explore the hinterland, I say," he said.
"If you're driving from Brisbane, turn right [instead] and drive up there to our wonderful green behind the gold."
Other closures today included Alexandra Headland, Rainbow Beach, Mooloolaba, Discovery Beach at Marcoola, Mudjimba, Kings Beach, Main Beach on North Stradbroke Island, and Agnes Water in central Queensland.
Lifeguards have rescued two swimmers at Tallebudgera Creek and four swimmers at Maroochydore.
The BoM issued a severe weather warning for abnormally high tides and dangerous surf from the tip of Fraser Island to the New South Wales border.
The pounding waves could cause significant beach erosion.
Mr Tate said council has heavy machinery on standby to help prevent sand erosion.