After being blasted by heat as thousands returned to work this morning, commuters in Sydney and Melbourne could face storms on the way home.

The change has already swept up much of the east coast and is set to hit the east of the state and then Sydney tonight.

It will also bring a massive temperature drop.

While Sydney saw 30 degrees today, it’ll drop to between 20 and 25 degrees on Tuesday.

“It’s going to bring a significant temperature drop, a burst of fresh southerly winds and rainfall,” BOM meteorologist Miriam Bradbury, said.

Most of NSW is at risk of thunderstorms. But the Central and Southern Tablelands of NSW, and parts of the Illawarra, are most at risk.

“In these areas severe storms may bring heavy rainfall that could lead to flash flooding,” Bradbury said.

Tuesday into Wednesday, north and central eastern NSW could see more rain and storms.

Large hail and damaging winds are also forecast.

The end of the week will bring more showers.

Storms are possible across much of the state this afternoon and evening.

Parts of South Australia and Tasmania are also in the firing line.