Mini-tornado rips roofs from homes and warehouses and leaves trail of destruction as devastating storm smashes the NSW Central Coast after blistering heatwave

The wild weather has battered parts of Australia, with damaging winds blowing the roofs off homes, destroying properties and leaving thousands without power.

About nine homes were damaged about 4pm on Saturday when devastating storms destroyed parts of the entrance and long jetty, on the NSW central coast, with one person trapped under rubble in a house.

The roof of Long Jetty Automotive Engineering, located on the corner of Minto Ave and Central Coast Hwy, was blown completely off the building, causing the force to also bring down some of the walls.

The roof of a neighboring house blew, trapping at least one person for some time.

Gabrielle Woodhouse from the Bureau of Meteorology said there were thunderstorms in the Central Coast region throughout the day.

“This storm in particular was driven by a moist and unstable air mass, bringing that devastation to places like Long Jetty,” she said.

“We're expecting some showers or another thunderstorm to the west (Sunday), but we'll at least see some cooler conditions.”

The weather bureau said the damage was caused by an “intense” and “fast-moving” storm that passed through the area this afternoon.

Trees and power lines collapsed on several roads in the area as the city was hit by flash floods.

A severe weather warning was issued for Greater Sydney and the Illawarra after cool changes occurred around Saturday afternoon

A roof was blown off a house on the NSW Central Coast on Saturday afternoon after high winds tore the roof off a factory

Sydney is expected to be hit by gusts of 70 km/h on Saturday evening, which could increase to 90 km/h later this evening.

There is also a warning for severe thunderstorms threatening large hail and damaging winds for the Hunter, South Coast, Snowy Mountains and Mid-North Coast forecast districts.

The bad weather comes after parts of the NSW coast were hit by 40 degree heat.

Penrith and Richmond in western Sydney reached 43C, while Badgerys Creek, Frobes and Coondobolin were among the NSW Central West to reach 44C.

Total fire bans have also been imposed in five districts across the state, with firefighters battling to control dozens of out-of-control blazes.

Health authorities previously urged concertgoers attending events across Sydney to stay in the shade and keep themselves hydrated by drinking plenty of water.

A roof was blown off a warehouse (pictured) in Long Jetty on the NSW Central Coast on Saturday after damaging winds lashed this town in the afternoon

Damaging winds caused flash flooding in areas of NSW's north coast, with the weather bureau saying the weather system was 'fast-moving' and 'intense'

Several properties were damaged by the gusty winds that left a trail of destruction across homes after most of NSW was baked in scorching heat on Saturday