Emergency services have conducted multiple swiftwater rescues overnight as South East Queensland storms caused flash flooding, with one couple swept from their campsite on a blow-up mattress.

Key points: A man and woman were rescued after being swept away from their campsite on an inflatable mattress

A man and woman were rescued after being swept away from their campsite on an inflatable mattress A tropical cyclone is expected to remain well off the Queensland coast

A tropical cyclone is expected to remain well off the Queensland coast The heaviest rain was in the upper Brisbane Valley west of Kilcoy

The man and woman were found clinging to a tree after drifting 100 metres in floodwaters at Morayfield, north of Brisbane.

Paramedics said they had been camping near a creek when the water swept their mattress from the site near Elm Court.

They were rescued at 11:30pm and taken to Caboolture Hospital.

A tree has blocked Sandgate Road at Clayfield, a major route into the city. ( Supplied: Tonile Wortley )

Meanwhile, a man who was reported missing in flash flooding at Nanango in Queensland's South Burnett region, has been found safe and well.

Police said he was reported missing after he was spotted pushing a black Ford Falcon in floodwaters at Nanango on the Burnett Highway just after 8:00pm.

The car was later found abandoned.

Officers conducted extensive searches overnight and managed to make contact with him this morning.

Police found the abandoned car at Nanango this morning. ( ABC News: Elly Bradfield )

South Burnett State Emergency Service controller Arthur Dawson said the man was lucky to be alive after being swept off the road.

"He's basically driven into floodwater that was quite a depth across the highway," he said.

"Somehow he's lost control of the vehicle and ended up on the left hand side of the road. With the car on the angle that it was on the road, it's a miracle that he actually got out and was alive."

Mr Dawson urged drivers to heed the advice of authorities and never attempt to drive through floodwaters.

"A lot of the time you get what's called washout underneath the road, which you can be driving into an actual hole."

Lightning strikes over South Brisbane. ( Supplied: Russell Stevens )

Another man was trapped in his flooded car for 25 minutes after it was washed off the road at Willawong in Brisbane's west.

At Yalangur, north-west of Toowoomba, two people were rescued when their car washed off the road.

A plane lands in Brisbane during last night's storm. ( Supplied: Jo Ward )

One of the pair, a man in his 70s, was taken to Toowoomba Hospital in a stable condition

After 1:00am a teenager was assessed by paramedics after his car was caught in floodwaters at Kurwongbah, north of Brisbane.

The flooding came as parts of South East Queensland were hit with torrential downpours.

The Bureau of Meteorology's Matt Bass said the heaviest rain was in the upper Brisbane Valley west of Kilcoy, where Gregor Creek recorded 102 millimetres in one hour.

"[There was] extreme sort of rainfall through there and that has resulted in some minor to moderate flooding in the upper reaches of the Brisbane River above Wivenhoe Dam," he said.

"Now of course that will just flow into the dam and will not cause any issues further down.

"Yeah, 100mm in an hour is very intense sort of rainfall we don't see too frequently, so in that particular area where that rainfall fell, I'm sure there was significant river rises and flash flooding for sure."

Seqwater said the water grid increased by just over 1 per cent overnight, bringing it to 58.8 per cent capacity.

Crews spent the morning removing fallen trees around Brisbane. ( ABC News: Stephen Cavenagh )

Welcome falls on hinterland

At Kalbar on the Scenic Rim, land owner Ross Smith said the rain had been good news for his horses.

"We had 60mm in 40 minutes, it just pelted down," Mr Smith said.

"The creek behind our property that hasn't had water in it for two years was flowing for the first time.

"Before it was just dirt and now with green around you see more people out and about just talking about the rain."

Retired Kalbar local David Murtagh has lived in the area for more than 20 years.

"It's been terrible out here, just smoke, dust, drought and then, the rain," he said.

"The recent rain was good to have, the dams aren't full yet but the creeks are starting to flow."

Paddocks around Kalbar had been cracked and dry but are thriving after recent rain. ( ABC News: Anna Hartley )

Vicki Kruger, who lives near Kilcoy, north-west of Brisbane, said she received 104mm of rain overnight.

"This is just wonderful," she said of the swollen Brisbane River.

"This was just a muddy puddle two weeks ago.

"We rely on tank water. We've got two 10,000-litre tanks. They're now full — overflowing."

Vicki Kruger says the rain has made an amazing difference to Kilcoy and surrounds. ( ABC News: George Roberts )

Tropical Cyclone to 'drift past' Queensland

Tropical cyclone Uesi will bring more showers and big seas to Queensland's coast later this week but is expected to remain well off the coast.

BOM said the slow-moving system is currently north-north west of New Caledonia.

Senior Forecaster Matt Bass said it's moving south.

"That's likely to drift past south-eastern Queensland off shore but still might get a few showers coming out from that over Friday.

"Winds will also pick up about the coast and swells pick up about the coast as well.

"Potentially a little bit of shower activity from Cyclone Uesi before finally over the weekend it looks like the shower activity really will calm down."