A severe weather warning has been issued for the NSW Illawarra and south coast as foul weather appears set to batter the state.
Gale force winds blowing up to 65km/h and more than 100mm of rain are forecast to hit the Illawarra region as a low pressure system forms off the coast on Sunday morning.
But without the accompanying king tides and 100km/h winds of early June's fatal storms, authorities don't think Sunday's storms will be as destructive.
"It's going to move away quickly," a Bureau of Meteorology forecaster told AAP on Saturday afternoon.
The BoM warned NSW south coast residents that heavy rain may lead to flash flooding in areas including Wollongong, Nowra, Bowral and Eden.
Flash flooding warnings have also been issued for nine rivers and catchments.
The worst weather should clear by Monday.
The NSW emergency service has advised residents to move vehicles away from trees, secure loose items and keep a safe distance from fallen power lines.
Residents should also avoid driving through flood waters.
"People living or working along rivers and creeks must monitor the latest weather forecasts and warnings and be ready to move to higher ground," the SES said.
Tasmania was thrashed by the early June storms but forecasters say the Apple Isle is unlikely to be hit again, with the low pressure system expected to move eastward.
Meanwhile, Sydney's Northern Beaches Council is scrambling to protect Collaroy homes teetering on eroded coastline.
Residents remain in temporary accommodation but have been allowed to return to their homes to collect belongings.
More than 300 flood rescues were carried out by authorities during the June deluge, which claimed the lives of two men.
More than 30,000 insurance claims worth a combined $235 million were lodged across the east coast.
