Several people who fled to safety on the roofs of their flooded homes have been rescued after more than three metres of rain drenched parts of the NSW Mid North Coast in 24 hours.
Residents in Corindi, north of Coffs Harbour, had to evacuate to their roofs when floodwaters swept through roads and homes.
Coffs Harbour State Emergency Service deputy unit commander Martin Wells said several people had to be rescued.
"It's really disappointing that drivers continue to head through these floodwaters when it's clearly impassable," he told radio 2GB on Thursday.
"It's putting theirs and their family's lives at risk and of course our teams that are heading out to rescue them from those situations," he said.
Roads and bridges likely to be 'impassable'
Meteorologist Helen Kirkup with the Bureau of Meteorology told Yahoo News Australia they are double-checking the 309mm figure because it is “particularly high” but that initial research shows it “may be real”.
Because the thunderstorms emerged one after another, some areas on the Mid North Coast received more signifiant rainfall than their neighbours, she said.
A severe thunderstorm warning was in place for Grafton overnight.
“Lots of rain fell in a short amount of time, which caused flash flooding,” Ms Kirkup said.
The Bureau of Meteorology said moderate to heavy rainfall associated with thunderstorms has been recorded across the Orara River catchment in the Coffs Harbour region, affecting the towns of Glenreagh and Coutts Crossing.
The SES is warning Glenreagh Village may be isolated on Thursday if river levels continue to rise and residents should prepare for possible isolation.
It's also likely that all road and bridges to and from Glenreagh will be impassable once the river exceeds 7.4 metres at the Glenreagh gauge.
The Kremnos and Kungala area may be isolated and residents should prepare as it's likely that all evacuation routes from those towns will be impassable once the river exceeds 5.8 metres at the Glenreagh gauge.
The SES said people should refrain from driving or walking through floodwater, stay out of rising water and seek refuge in the highest available place.
Emergency crews called after freight train derails
Fire and Rescue NSW were on the scene near Morrows Road, Nana Glen, near Coffs Harbour after thunderstorms led to a freight train’s derailment just after 2.15am on Thursday.
Multiple wagons of freight train, which was travelling from Brisbane to Melbourne, derailed after encountering a track washout.
Half of the 1500m train derailed, with one of the locomotives in a paddock and the two other locomotives upright.
One of the locomotives leaked up to 8000 litres of diesel and 16 carriages have jack-knifed, four of which are now stuck in floodwaters.
A small fire occurred in one of the carriages however that was extinguished by the train driver who was not injured, a FRNSW statement says.
However, flooding is hindering progress for emergency services and the clean-up could take days.
NSW Police and the NSW Environmental Protection Agency are on the scene and a transport safety investigation is under way.
It will be undertaken by the Office of Transport Safety Investigations, which conducts rail safety investigations in NSW on behalf of the Australian Transport Safety Bureau.
Weather: What’s to come?
Ms Kirkup said said it is hard to predict which areas will receive more rain so the bureau is keeping an eye on patterns on Thursday, during which the coast has a forecast of 80 per cent rain.
There are possible late showers on Friday and throughout the weekend before clearing on Monday.
La Nina has helped the storms along by providing an atmosphere with lots of moisture that can fall down as rain.
Do you have a story tip? Email: firstname.lastname@example.org.