The Bureau of Meteorology has issued a severe thunderstorm warning for people in Sydney and parts of Blue Mountains/Hawkesbury, Gosford/Wyong, Wollondilly/Wingecarribee and Greater Wollongong areas. 

At 12:30pm, severe thunderstorms were detected on the weather radar near Camden, Campbelltown, Penrith and Picton. These thunderstorms are moving towards the east.

They are forecast to affect Hornsby, Parramatta, Sutherland, Sydney Olympic Park, Richmond and Liverpool by 1:00 pm and Sydney City, Sydney Airport, the Sydney Harbour Bridge, Mona Vale and waters off Bondi Beach by 1:30 pm.

Damaging winds and large hailstones are likely.