A powerful storm has been identified in the south-western Sydney suburbs of Leppington and Bringelly, bringing with it the threat of hailstones and strong winds as it advances eastward.

“We’ve observed a substantial amount of storm activity building up over the past few hours,” noted Angus Hynes, a meteorologist with the Bureau of Meteorology.

“It’s now on the verge of moving through Sydney’s western regions,” he explained.

Hynes mentioned that the storm warnings have now been broadened to encompass the entire Sydney metropolitan area, highlighting two particular storm systems that are currently under close observation.

The stormy weather comes on the heels of a scorching day, with temperatures soaring to 34.7 degrees Celsius at Sydney Airport and exceeding 35 degrees in the city’s western suburbs.

Earlier today, Weatherzone had forecast that unstable weather was likely to develop as a cold front and low-pressure trough swept over the state and collided with a “much warmer” air mass.

“An upper-level trough passing over southeastern Australia on Friday will also help to destabilise the atmosphere, resulting in an outbreak of thunderstorms across central and northeastern parts of the state,” the site reported.

“Isolated supercell thunderstorms are also possible on Friday, particularly over central eastern NSW,” it added.

“If these supercells do form, they may cause destructive wind gusts in excess of 125km/hr and giant hail measuring more than 5cm in diameter.”