Freak storm lashes Sydney with heavy rain and lightning

A severe thunderstorm has swept swiftly through NSW this afternoon, with heavy rain lashing the state and plunging Sydney CBD into darkness in a matter of minutes.

All flights from Sydney airport were temporarily placed on hold due to lightning strikes, with normal services resuming just after 1pm.

Do you have photos of the storm? Send them through to contact@9news.com.au and remember to stay safe 

Sydney's western suburbs were hit the hardest, with Blacktown soaked by 19mm in just 10 minutes and Kings Langley receiving 20mm in the hour to midday.

PHOTOS: Freak storm lashes Sydney

The storm cell moved over the city in under 20 minutes before moving out to sea, but showers are expected throughout the rest of the afternoon.

Winds are also forecast to pick up when a southerly change arrives later today.

Golf ball sized hail was reported in the Picton area just before 1pm and marble sized hail reported near Camden before 2pm.

The Bureau of Meteorology issued a warning shortly before midday, with heavy rainfall and flash flooding expected.

Metropolitan Sydney, Gosford, Penrith, Parramatta, Wollongong and Campbelltown were all affected.

A severe thunderstorm warning is now in place for parts of southern Queensland.

Damaging winds and large hailstones are expected on the Southeast Coast and parts of the Central Highlands and Coalfields, Wide Bay and Burnett and Darling Downs and Granite Belt regions.

The system was also expected to hit Brisbane.