Parts of NSW have been lashed by strong winds and heavy rain, with the State Emergency Service warning of more severe weather into Wednesday.
SES volunteers had responded to over 350 calls for help from the public by Tuesday evening and thousands of homes have lost power.
"The worst-hit area was Orange, where a narrow part of the town bore the brunt of the damaging winds, which resulted in roof damage and fallen trees," the SES said in a statement.
The Bureau of Meteorology has issued a severe weather warning for damaging winds along the coast of Sydney, the Illawarra and northern parts of the South Coast from late Tuesday onwards.
A hazardous surf warning has also been issued for the Hunter, Sydney, Illawarra, Batemans and Eden coasts with people advised not to go fishing, swimming or boating.
Winds are expected to gradually ease below gale or damaging wind thresholds from Wednesday morning.
Flood warnings have also been issued for a number of rivers with flood rescue operators on standby.
Residents have been warned to not drive, ride or walk through floodwaters.
Power outages have also occurred with Endeavour Energy reporting cuts to around 18,000 homes, with emergency crews responding mainly in the Illawarra and Shellharbour regions and on the South Coast.
"Extra crews are being marshalled to assist with the repair efforts, with over 250 hazardous incidents to investigate," Endeavour said in a statement on Tuesday evening.
"It is likely that due to the damage that some customers will be without power overnight."