Damaging winds and damaging surf is forecast from May 21 to May 22.
Gale force winds are predicted from the Illawarra to the Batemans Coas. A hazardous surf warning is in place for the same area.
An emergency warning has been issued for Wreck Bay, Jervis Bay and Currarong.
According to the Bureau of Meteorology: "A deep low pressure system is expected to deepen near to the New South Wales coast overnight, potentially bringing damaging winds and surf.
"Damaging winds, averaging 70 to 80 kilometres per hour, with gusts exceeding 90 kilometers per hour, may be expected within the warning from late Thursday evening, and continuing all day Friday.
"Damaging surf, with significant wave heights reaching five to six metres, may be expected in the warning area, particularly about exposed parts, from early Friday morning.
"These damaging wind and surf conditions are expected to ease on Saturday as the low moves away to the east, though surf conditions will remain hazardous and winds strong and gusty."