Lightning strikes near Sydney Harbour Bridge in savage storm

A severe thunderstorm is bearing down on Sydney, with hail the size of 50c pieces and the iconic Harbour Bridge lit up by lightning.

Locals are also being warned to stay off the roads.

After a weather warning was issued at 1:30pm local time, Sydney Airport was forced to delay various outgoing flights, as hail, rain and lightning hit parts of the city.

Storms have hit the Penrith region in southwestern Sydney near Wollongong, where the temperature plunged 10 degrees in half an hour.