A severe weather warning has been issued for parts of the Coast and Highlands.
The system passing through could result in heavy rainfall, large, possibly giant hailstones and damaging winds.
Locations which may be affected include Bowral, Wollongong, Campbelltown, Braidwood, Katoomba and Goulburn.
The State Emergency Service is asking people to move their car under cover or away from trees, secure loose items around the house and stay away from fallen power lines.
IMAGE CREDIT: BOM