Police say the 69-year-old Killarney local was moving cattle to higher ground at a property along the Condamine River when flash flooding washed his car away around 8pm on Wednesday.
His body was found inside the vehicle by emergency services just after midnight.
Almost all of NSW – from the Queensland border and Lismore in the north to Albury at the Victorian border and the entire central west – was hit by severe thunderstorms and heavy rainfall on Wednesday.
Only the state’s far west and pockets of the South Coast and mid-north coast were spared the drenching.
The Bureau of Meteorology says sporadic thunderstorms will continue on Thursday with heavy rain expected and a risk of further flash flooding in parts of Queensland.
The Bureau of Meteorology has warned dangerous thunderstorms have been detected on the radar near Coolangatta and Miami in the Gold Coast region.
Intense rainfall is likely and could lead to “dangerous and life-threatening” flash flooding.
Falls in excess of 100mm has been observed in the 2 hours to 10:30am in the Gold Coast region.
Residents in the Wide Bay, Burnett and Southeast Coast areas have been warned that storms producing heavy rain are likely over the next several hours.
Almost 60mm was reported in an hour to 9:30am at Oyster Creek, south of Gladstone and there was 33mm in 30 minutes at Bundaberg South.
The Bureau advised that a coastal trough moving ashore is responsible for the slow moving thunderstorms.
The 69-year-old grazier had been moving cattle to high ground at a property on Condamine River Rd, Killarney, about 8.30pm on Wednesday, police said.
A flash flood swamped his vehicle and swept it downstream.
Emergency services were called to the scene and found the vehicle with the man’s body inside almost four hours later, about 100m downstream.
Police will prepare a report for the coroner.
Lismore in northern NSW was inundated on Wednesday, copping more than 120mm of rain falling in just three hours.
There was flash flooding in the town’s CBD and minor flooding of the Wilsons River.
NSW SES Assistant Commissioner Sean Kearns said Lismore had copped more than 200mm of rain between 9am and 5pm which resulted in 136 calls for assistance and 15 flood rescues.
Overnight SES crews had responded to 503 jobs, including 22 flood rescues, he told Nine’s Today show.
“Obviously we are still concerned about the mid-north coast and northern rivers area as there has been such heavy rain there since last Thursday.
“So these catchments are extremely damp and any further rain could see some river rises.
“We are also seeing warnings for the Hunter area, the Illawarra, so we do ask people to keep an eye out for the warnings and keep an eye on the weather,” he said.
A minor flood warning remains for the river, although levels are falling after it peaked around 8pm on Wednesday.
Just over the border on the Gold Coast, all beaches are closed on Thursday as council workers work to clear debris that has been washed up.
River levels at Coraki and Bungawalbin, south of Lismore, also peaked at minor flood levels overnight, with Woodburn further downstream due to peak on Thursday morning.
Coutts Crossing near Grafton is also flooded. The Orara River peaked at a moderate flood level late on Wednesday night, but is now falling.
Nearby Glenreagh is also experiencing minor flooding.
But there was some good news, with a number of evacuation orders and flood warnings throughout the state lifting on Wednesday.
The Clarence River peaked overnight causing minor flooding in Grafton, but the weather agency says no further flooding along the river is expected.
The flood watch for the Bellinger River was also downgraded.
Since the downpours began on Thursday, the SES has attended more than 2200 jobs and performed over 50 flood rescues.