An east coast low and flood warning remains in place for Sunday with possible heavy rainfall extending to the Hunter.
In a 5pm update on Saturday, the Bureau of Meteorology said a surface trough was expected to deepen offshore from the Illawarra area and move slowly northward over the remainder of the weekend.
An east coast low may form within the trough during Sunday and linger until Monday, which will prolong this significant rainfall event across multiple days.
Heavy rainfall which may lead to flash flooding is forecast for the Illawarra and Sydney, extending to the Hunter district over the weekend. Six-hourly rainfall totals between 70 to 120 mm are possible.
A hazardous surf warning has been issued for the Hunter on Sunday and Monday.
Strong to damaging winds averaging 50 to 70 km/h with peak gusts up to 90 km/h are possible along the coastal fringe later on Sunday, continuing overnight.
Heavy rainfall increases the potential for landslides and debris across roads.
A flood watch has been issued for coastal catchments from the Lower Hunter to the South Coast.