A tornado warning has been issued for Sydney and surrounding areas as an 'absolute monster' storm smashes Australia's east coast.
The Bureau of Meteorology issued the urgent weather warning to 'people in parts of the Blue Mountains/Hawkesbury, Greater Newcastle, Gosford, Wyong, Sydney and Greater Wollongong areas,' on Thursday afternoon.
Damaging winds, large hailstones and heavy rain have battered western with Penrith and Blacktown copping bearing the brunt of the system.
So far are no injuries have been reported but firefighters and police are working to secure the area.
'We've had quite an escalating storm situation within Sydney metropolitan area. As of around a half an hour ago, we have seen rotation within a thunderstorm which is moving through,' senior meteorologist Jordan Notara told 2GB radio on Thursday afternoon.
'We haven't as yet had any observations on the ground but the signatures that we are seeing on the radar are indicative of something that will produce damaging … wind gusts, large giant hail, again, quite a dangerous situation.'
The low pressure system is expected to move down the coast in the next 24 hours with weather warnings issued for residents from Queensland to Victoria.
NSW residents as far inland as Goulburn and Orange in the central west could feel the brunt of mother nature from Thursday night.
The ACT is also forecast to experience similar wet La Niña conditions as the wild weather system intensifies.
Queensland's south east has already been battered by rain and lightning since the early hours on Thursday morning.
Melbourne metro and areas across Victoria are experiencing some wet weather conditions as the low pressure system brings rain for the rest of the week.
Meteorologist Jonathan Howe said conditions were making it possible for tornadoes to form in south-east Queensland.
Brisbane (pictured) and areas of QLD's south-east was hammered by torrential rain from Thursday morning
More than 50mm of rain was recorded in just one hour on the Darling Downs in Queensland
Peak hour traffic crawls through Brisbane as heavy rain wrecked havoc on roads
A cold front hitting the east coast is causing the miserable conditions in Brisbane (pictured) and is set to move the wild weather to NSW and VIC
Rain and lightning has been pelting Brisbane (pictured) since the early hours of Thursday morning with severe thunderstorm and flash flooding warnings in place
'Today, the ingredients for a tornado really do line up. We cannot predict where they are going to form but the environment is there to see these super events,' he told the Today show.
'The advice is keep an eye on any of the advice is keep an eye on any of the warnings because when they do crop up they cause a lot of problems.'
The Bureau of Meteorology's David Wilke said thunderstorms forming yesterday will turn into full-blown monster storms on Thursday.
'We're going to see a cold front moving through NSW ... it's going to bring pretty widespread areas of showers and storms and some reasonable rain through the southern part of the state,' he said on Wednesday.
Brisbane (Story Bridge pictured) is on alert with meteorologists predicting flash flooding and a potential tornado
Meteorologist Jonathan Howe says conditions in QLD could see tornadoes forming with tennis ball-sized hail likely in south-east QLD and areas of NSW