'Nearly cyclonic': Wild weather hits NSW north coast, south east Queensland

Large hail and possible flash flooding have been forecast for parts of NSW as severe storms lash the state. Meanwhile, southeast Queensland has experienced flash flooding and has also been warned to prepare for more.

The roof of a small town pub has been torn off by strong winds described by locals as "nearly cyclonic," as storms lashed the length of NSW.

The Clarence Hotel's roof was stripped off on Tuesday afternoon during a raging storm that caused widespread damage to the Northern Rivers Region, including flash flooding.

Maclean locals uploaded photographs of the storm's aftermath to social media, showing the town's pub without a roof and debris scattered through the streets.

Waterview Motel owner Brian Koorockin described the winds as "nearly cyclonic".

"It started off as rain, then thunder and lightning and then the wind just picked up and pulled roofs off, pulled trees out of the ground and knocked over fences," Mr Koorockin told AAP.

"The hotel roof is over the top of powerlines...it's sort of hanging off the side, it kind of flipped off."

Mr Koorockin said he wasn't aware if anyone was inside the pub when the roof lifted off, but joked there was a good chance some regulars were in attendance.

"There would have been a couple of bar flies in there," he said.

NSW Police issued a warning for Maclean residents to use caution when travelling through the area after the storm.

Mr Koorockin said the town had lost power around lunchtime, leaving his guests with no air conditioning or light.

"I've got a motel full of people, all I've given them is just torches, they're all probably kicking back relaxing," he said.

Cawongla received 32mm of rain in 30 minutes, while 76km/h wind gusts were reported at Evans Head.

Meanwhile, golf-ball-sized hail was recorded at Bullburra in the Blue Mountains west of Sydney.

While thunderstorm warnings were issued for much of the NSW coastline, many were eased in the evening.

Storms continue in Queensland 

Severe storms are continuing across Queensland after flash flooding in parts of the state's southeast, with residents warned of potentially dangerous winds and large hailstones.

The Bureau of Meteorology on Tuesday afternoon issued a severe thunderstorm warning for Logan, Redland City, Noosa and parts of Ipswich, Gympie, Somerset, Scenic Rim, Gold Coast, Sunshine Coast and Brisbane.

Storm pockets were still tracking across the state hours later, from Rockhampton to the NSW border and as far west as Emerald.

Flash flooding occurred in parts of the Scenic Rim region and the Gold Coast Hinterland, with Beaudesert being the worst hit after 50-60mm of rain within an hour and more expected to follow.

"The worst flooding is the Beaudesert side of Biddaba road - it is cut both ways," Queensland Police wrote on Twitter.

Police have issued further warnings to motorists to avoid flooded roads after a driver became stuck in floodwaters at Pimpana, south of Brisbane.

A spokesman for Queensland Police said no rescues were required.

More storms this summer: BOM 

The Bureau of Meteorology has warned storms were likely to be more common this summer due to higher humidity.

Forecaster Jake Phillips told ABC that more hail, rain and thunderstorms are expected in coming months.

"Climatologists are suggesting the months ahead are likely to be a bit more humid than average with a bit higher than average rainfall," he said.

"It's only the start of January and storm activity usually sees a peak in December and January, but we see quite a lot of storm activity through March sometimes even April."

Published 2 January 2018 at 7:12pm, updated 3 January 2018 at 6:40am