The storm season may have signalled its arrival as hail and wild lightning wreaked havoc across parts of NSW and Queensland late Wednesday.

Rumbling storms bringing large hail swept across Sydney and knocked out power to tens of thousands of homes, with more than 10,000 lightning strikes recorded.

In the north-east corner of NSW, a foreboding dark sky gave warning of what was to come — fierce hailstorms dumping thick blankets of ice.

Hail slammed a number of towns, including Murwillumbah on the North Coast, Parkes in the Central West and the highlands south-west of Sydney.

Around 3pm, a storm lashed Murwillumbah with hailstones about 4cm in diameter.

Hail turns the fields white in the Tweed Valley. Photo: Neil Baker (Twitter)

Residents posted photos to social media of large piles of ice, and fields carpeted in white.

Hail was also reported at Grafton a couple of hours later, and photos showed roads covered in white at Uki, forcing cars to pull over.

The Bureau of Meteorology (BOM) said the thunderstorms “blossomed” across northern NSW and south-east Qld after a dry and clear morning.

“These satellite images from today show thunderstorms sprouting up across Qld and NSW after a clear sunny morning,” the BOM warned on X (Twitter).

Tweet from @BOM_au

The bureau issued a number of severe weather warnings on Wednesday afternoon.

Meteorologist Angus Hines said the stormy conditions could continue into Thursday on the eastern seaboard.

He warned that weather alerts could change very quickly and urged Australians to stay across updates as the season kicked into gear.

“When thunderstorms are involved, things move very, very quickly,” he said.

In Sydney, power was lost in a number of suburbs including Hornsby and Asquith.

Some domestic and international flights were delayed at Sydney Airport.

Nine News reports lightning struck the home of Maroubra resident Simon Hodge who heard a bang followed by a knock on the door.

“The biggest bang I’ve ever heard in my life, just scared the bejesus out of me,” he said.

“Next thing I know, someone was banging on the door saying lightning struck the building and there’s smoke coming out of it.”

Hail surprised residents of Reesville on the Sunshine Coast hinterland in Qld. Photo: Brush Turkey Enterprises

Storms also swept across south-east Queensland for the second afternoon this week, with the sky turning an ominous green-grey shade.

Storms in the Sunshine Coast hinterland brought lightning and drum-like thunder.

A hailstorm also battered the suburb of Fairfield in Brisbane.