Bundaberg received 340 millimetres in the deluge in its wettest October day on record, with nearby Woodgate receiving 306mm and Maryborough 240mm.
The Bureau of Meteorology (BOM) said conditions had been conducive to producing a tornado, but because it had no witness reports of seeing a funnel, it could not say it was definitely a tornado that swept through the region.
"Looking at the damage that's occurred it was just so incredibly localised and that really does say to us … it looks like it could have been a water spout that moved ashore or a tornado," BOM forecaster Michelle Berry said.
Premier Annastacia Palaszczuk said there had been dozens of calls for help due to fallen trees and branches, but there were no reports of injuries or the need for swift-water rescues.
'Mini tornado … dropped on top of us'
Bundaberg residents described how their homes and gardens were torn apart during the wild weather, which was described by some as a "mini tornado".
Wendy Gillard, of Dunn Road at Avenell Heights, said she was actually watching the movie Twister on television when the power went off, and the noise of howling wind did not stop.
"The sound was just terrifying really — I came out the back to have a look and the fences were down, and the tree was down," Ms Gillard said.
"As I looked out the door, the wind or whatever it was picked up the shed and just blew it as I was watching out the back door."
She said the noise was like a "really fast whirring sound".
"Then just the banging of things, crashing through the air — it was pretty scary," Ms Gillard said.
Tegan Smith, also from Avenell Heights, said she and her children took shelter in the home office.
"It was terrifying, the roar was really loud," Ms Smith said.
"I saw what looked like a tile fly past the window and I just knew we had to hide and get somewhere safe."
When they emerged to survey the damage, Ms Smith said they were surprised to find the shed demolished, but other items intact.
"It would have to have been like a mini tornado that just picked up and dropped on top of us," Ms Smith said.
"Our shed is flattened and yet the furniture out near the pool hasn't even moved."
Fellow Avenell Heights resident Melissa McLaren said she was making lunch when "the house just exploded".
"The windows shattered, the roof came off, everything fell down," Ms McLaren said.
"I didn't know what it was — I thought it was an earthquake."
She called the SES for help but volunteers deemed the battered house too unsafe to erect a tarpaulin.
Resident Bronnie Durston described her terror after a "wind storm" swept through her home on Bundaberg's southside.
Ms Durston said she and her family barricaded themselves inside.
"You could hear the hum in the air as it came through — I said 'oh, that sounds funny', thinking it was something on the TV," she said.
"Next minute you could literally feel the air move through the house — you could almost feel even like a lifting — I've never experienced anything like it before in my life."
BOM said the worst of the rain had now moved out to sea and across into New South Wales.
However, BOM senior forecaster Andrew Buffalino said more showers and thunderstorms were expected to redevelop in the state's south-east this afternoon and this evening.
"Numerous locations above 250 millimetres which also extended all the way down to Maryborough — so quite extensive area," he said.
"We didn't get too much down in the far south-east but Noosa Heads and the Sunshine Coast got 124 millimetres and most of that was overnight.
"Around Brisbane, the heaviest falls was around Mt Glorious with 90 millimetres and Brisbane city itself only recorded 35 millimetres."
The State Emergency Service (SES) received more than 150 calls for help after a number of homes were damaged during the deluge.
Houses flooded, roofs blown off: SES
SES local controller Lyn Blackwell said they called in extra help for the clean-up in Bundaberg.
"There's roofs off, stuff flown around like debris, and that but mainly the water going into houses — the flooding of the houses — is probably the main thing," she said.
"I have got crews coming from Childers and Gin Gin coming over to help us as we speak, I've got people coming over from Woodgate helping us."
Ergon Energy spokesman Rod Rehbein said 5,000 properties lost power across the region on Sunday but it had all been restored.
"We had reports of more than a dozen powerlines down, roofing in the powerlines, trampolines in the powerlines, so it was quite chaotic scenes," he said.
'Patio wrapped around a tree'
Storm damage has been hit and miss in the Hervey Bay region, with the coastal River Heads area copping the brunt of destructive winds.
Councillor Darren Everard said gales cut a swathe through the neighbourhood at about a 5:45pm on Monday with trees uprooted, patios ripped away and residents in disbelief.
Councillor Everard said the clean-up would be difficult as builders assessed damaged homes and council staff worked to make the area safe.
"It's a very surreal situation down here — I'm actually just looking at a patio now wrapped around a tree," he said.
"There's a water tank about a kilometre from where it started — it's going to be a tricky clean-up."
He said residents were still taking stock of the damage from the destructive winds.
"It's cut a bit of a swathe through Cove Boulevard," he said.
"It's very hit and miss — what has and hasn't been damaged.
"We've got builders out here and a lot of residents are now just waiting for their insurance assessment to come out."
After 78 days without rain in the Bundaberg region, farmers were holding out for a fall.
But Bundaberg Fruit and Vegetable Growers chairman Alan Mahoney said some farmers would have significant losses due to the huge downpour.
"It was definitely a hard drop — it all depends on the commodity and the different stage, but there's going to be varied amounts of damage and some crops just wouldn't have handles it all unfortunately," he said.