Severe thunderstorm warnings have been issued for large parts of Australia's east coast, with damaging 90km/h winds, flash flooding and giant hailstones expected to wreak havoc Wednesday afternoon.
New South Wales and Queensland have been battered by the powerful storm system since Sunday night, and the Bureau of Meteorology warns the incoming deluge will be just as destructive.
In the past few days, the SES have responded to hundreds of calls for help with flood rescues and upturned trees.
Tens of thousands of homes were also left without power.
Severe thunderstorm warnings have been issued for large parts of Australia's east coast, with damaging 90km/h winds, flash flooding and giant hailstones expected to wreak havoc Wednesday afternoon (pictured, dark clouds roll in over the Sydney Harbour Bridge)
On Monday Sydney's CBD was hit with severe thunderstorms (pictured, pedestrians have their umbrellas out during the downpour)
'We have an upper trough with a lot of moisture triggering unstable atmospheric conditions and that is driving the development of all these thunderstorms,' BoM Duty forecaster Aberar Shabran told Daily Mail Australia.
'Today's thunderstorms are likely to produce large hailstones, damaging winds and heavy rainfall that may lead to flash flooding.'
Locations which are likely to be the most affected in New South Wales include Lismore, Grafton, Coffs Harbour, Armidale, Orange, Moree and Dubbo.
Meanwhile, Tamworth has already reported hailstones this afternoon between two to five centimeters in size, according to Mr Shabran.
The State Emergency Service warns residents in affected areas to move their vehicles under cover and away from trees, to secure loose items in yards and on balconies and to keep at least eight meters away from fallen power lines.
Sydney is expected to dodge the worst of the wild weather after copping a drenching on Monday, but Mr Shabran says the metro area could see a 'shower or two' overnight.
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Sydney is expected to dodge the worst of the wild weather after copping a drenching on Monday, but Mr Shabran says the metro area could see a 'shower or two' overnight (pictured, dark clouds roll in over Bondi Beach)
But the Central Coast is expected to see intense rain, along with areas west of the Blue Mountains.
In Queensland, 'very dangerous' 125km/h winds are predicted to lash Caboolture, north of Brisbane, Caloundra and Maroochydore on the Sunshine Coast, as well as other parts of the Sunshine State.
'Today will be another very active and possible dangerous day for parts of southeast Queensland and far northeast New South Wales,' BoM meteorologist Dean Narramore said.
'But these impacts will be very localised with the very hit-and-miss nature of thunderstorms.'
Several main roads were flooded by Tuesday evening, leaving motorists stranded and banked up in 'nightmare' standstill traffic as hail hammered down on parts of the state.
Rescue crews were called to flooded roads where cars were submerged as the heavy deluge caused waters to rapidly and unexpectedly rise.
One stranded motorist was forced to seek refuge on the roof of his car while waiting for a Swift Water Rescue crew to free him.
In other parts of the city, drivers returned to their cars which were parked at garages and bus stops to learn they'd been flooded, while pictures show bins and random objects floating down main streets.
Members of the Swift Water Rescue team from the Queensland Fire and Emergency Services were seen searching flooded cars on Longlands Street at Woolloongabba in Brisbane on Tuesday afternoon
Flooded cars are seen on Longlands Street at Woolloongabba in Brisbane on Tuesday following torrential rain
Beachmere recorded 80mm of rain in an hour on Tuesday, while 70mm bucketed down on The Upper Lockyer, west of Brisbane. Pictured: Flooded cars are seen on Longlands Street at Woolloongabba in Brisbane
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Several car accidents had been reported by 6.30pm, while trees were down and flash flooding blocked access to other main roads out of the state's capital.
RAQC urged Queenslanders to stay at home and said even as the rain eases, the repercussions of the storm will last well into the night.
Flooding was also reported in Gatton, east of Toowoomba, and Beachmere, near Caboolture.
'Eighty millimetres of rain in an hour is hard to get rid of,' meteorologist Rosa Hoff said. 'Very damp indeed.'
Beachmere recorded 80mm of rain in an hour on Tuesday, while 70mm bucketed down on The Upper Lockyer, west of Brisbane, the Bureau of Meteorology reported.
'That's a month's rain in the space of an hour,' meteorologist Felim Hanniffy told AAP.
One motorist was pictured seeking refuge on the roof of his car, which was almost entirely submerged
The series of severe thunderstorms pushed west towards Warwick, Toowoomba, the Lockyer Valley and Kilcoy earlier on Tuesday. Pictured: Rescue teams searching for trapped passengers
'In some areas of northern Brisbane 50mm fell in 30 minutes.'
Almost 50mm of rain fell in an hour at Kalbar in the Scenic Rim and more than 60mm of rain dumped on Helidon, near Toowoomba.
The series of severe thunderstorms pushed west towards Warwick, Toowoomba, the Lockyer Valley and Kilcoy earlier on Tuesday.
At least 5,500 homes lost power as a result of the horror weather.
But by evening the line of massive storms had moved east out to sea and the bureau cancelled a severe thunderstorm warning for the southeast coast and parts of the Capricornia, Wide Bay and Burnett and Darling Downs and Granite Belt.
There have also been reports of 'mini tornadoes' in Warwick, 130 kilometres south-west of Brisbane.
Photos of mini tornados reaching into the grey skies near Warwick have been shared across social media as residents brace for more wild weather
While they look like tornadoes, funnel clouds are in fact far smaller and don't reach the ground, but can still be extremely dangerous
The funnel clouds spotted in Brisbane on Tuesday afternoon were caused by the high pressure rainfall and damaging winds.
While they look like tornadoes, funnel clouds are in fact far smaller and don't reach the ground, but can still be extremely dangerous.
'These mid-air funnels are very deceiving and the only way to discount their threat is to look at the surrounding clouds for clear signs of rotation,' the Storm Spotters' Handbook states.
In NSW, crop growers are praying heavy rain forecast for the state doesn't wash away hopes of their first bumper harvest in years after suffering through drought, dust storms and bushfires.
Wet, windy weather and scattered hail has threatened farmers in parts of the state's interior since Friday, a big change from 12 months ago, grain farmer and NSW Farmers Vice President Xavier Martin told AAP.
But the rain isn't entirely welcome, he says, with concerns the adverse weather could ruin crops and kick farmers while they're down.
Waterlogged grain crops may start to sprout, meaning they are only suitable for stock feed, and wind and hail could knock seeds to the ground, he says.
'Every event puts at risk the quality of the seeds,' Mr Martin said.
'It might only sound small when you say 10 or 20 per cent damage, but ... for some farmers that ten per cent that is lying on the ground is the bit they really needed in their silo to be able to sell and make a profit.'
Mr Martin's crops in the Liverpool Plains near Tamworth have thus far been spared hail, but farmers in Coonamble and other parts of the state haven't been so lucky.
Rescue workers from the Queensland Fire and Emergency Services search flooded cars on Longlands Street in Brisbane
The series of severe thunderstorms pushed west towards Warwick, Toowoomba, the Lockyer Valley and Kilcoy earlier on Tuesday. Pictured: Queensland Fire and Emergency Services search flooded cars at Woolloongabba in Brisbane
THE WEATHER IN YOUR CITY
SYDNEY
Wednesday: Min 13. Max 21. Showers
Thursday: Min 15. Max 21. Shower
Friday: Min 14. Max 23. Shower. Possible late storm
Saturday: Min 17. Max 25. Shower or two. Possible storm.
MELBOURNE
Wednesday: Min 10. Max 19. Partly cloudy
Thursday: Min 11. Max 19. Shower or two
Friday: Min 12. Max 18. Shower or two
Saturday: Min 12 Max 18. Shower or two.
CANBERRA
Wednesday: Min 7. Max 19. Shower or two
Thursday: Min 8. Max 20. Shower or two
Friday: Min 9. Max 21. Shower or two. Possible storm
Saturday: Min 12 Max 19. Showers.
DARWIN
Wednesday: Min 25. Max 32. Showers
Thursday: Min 25. Max 33. Showers
Friday: Min 25. Max 33. Showers
Saturday: Min 26 Max 34 Mostly sunny.
BRISBANE
Wednesday: Min 18. Max 27. Showers. Storm likely
Thursday: Min 18. Max 31. Sunny
Friday: Min 16. Max 31. Sunny
Saturday: Min 19 Max 31. Shower or two. Possible storm.
ADELAIDE
Wednesday: Min 9. Max 21. Sunny
Thursday: Min 11. Max 21. Shower or two
Friday: Min 11. Max 20. Shower or two
Saturday: Min 12 Max 20. Partly cloudy.
PERTH
Wednesday: Min 14. Max 25. Partly cloudy
Thursday: Min 13. Max 32. Sunny
Friday: Min 18. Max 36. Sunny
Saturday: Min 19 Max 27 Partly cloudy.
HOBART
Wednesday: Min 9. Max 15. Shower or two
Thursday: Min 8. Max 17. Showers
Friday: Min 10. Max 16. Showers
Saturday: Min 8 Max 19 Partly cloudy.
Source: Bureau of Meteorology