The weather bureau has warned beachgoers against entering the water, with localised flooding and coastal erosion possible.
Beachgoers along the NSW and southern Queensland coast are being urged to stay out of the water as hazardous surf wreaks havoc on beaches.
The Bureau of Meteorology says a hazardous surf warning remains active on Friday and into Saturday for the Byron, Coffs, Macquarie, Hunter, Sydney, Illawarra, Batemans, and Eden coasts as well as the Fraser, Sunshine and Gold coasts in Queensland.
In addition, the bureau warns the “very heavy surf” could lead to localised damage and coastal erosion and abnormally high tides could cause flooding.
“A large and intense low pressure system is forecast to deepen over the Tasman Sea today and Saturday, generating very heavy surf along the NSW coast,” the bureau said.
“This will coincide with abnormally high tides along the coast during this evening and Saturday evening.
“These conditions should ease on Sunday as the low moves away to the east.”
Surf Life Saving NSW director Joel Wiseman said forecast swell conditions could reach six metres offshore.
“Beaches are not patrolled at this time of year, and even experienced surfers will struggle in these conditions. We’d advise giving the rock fishing a miss altogether this weekend,” Mr Wiseman said.
“It’s just not worth the risk”.
SLSNSW club call-out teams, duty officers and surf rescue assets are on standby to respond to “critical coastal incidents”; however, the extreme wind and surf conditions will limit the ability of lifesavers to come to people’s aid.
Coastal erosion is expected to develop along the coast from Friday afternoon and into Saturday, before easing on Sunday.
“South and southeast facing surf zones are at highest risks of being exposed to this surf,” the bureau said.
“Beach conditions in these areas could be dangerous and people should stay well away from the surf and surf-exposed areas.”
Abnormally high tides could cause seawater flooding of low-lying areas along Old Bar, Coffs Harbour, Port Macquarie, Newcastle, Sydney, Wollongong and Batemans Bay.
Surf Life Saving Australia is urging swimmers to “only swim between the red and yellow flags” and stay out of the water if the beach is closed.
The hazardous surf is also rolling into Queensland’s Fraser, Sunshine and Gold coasts.
It comes as a cold front sweeps across the Sunshine State that will deliver below-average temperatures and frost for some parts of the state for the next four days.