The fire that devastated Nymboida and surrounding areas last Friday and Saturday was so intense that it created its own weather, known as flammagenitus.
More commonly known as pyrocumulonimbus clouds, the phenomenon formed a thunderstorm as a result of the intense bushfire’s smoke plume – this phenomenon is also caused by nuclear bomb blasts and volcanic ash clouds.
“The pyrocumulonimbus cloud creates a weather system in front of the fire and can cause new ignitions from dry lightning strikes, further increasing the danger,” Clarence Valley Rural Fire Service (RFS) public liaison officer Jonty Bruce said.
Now officially known as the ‘Liberation Trail’ fire, it had burnt 135,850 hectares and was out of control as of 10.20am on Monday.
The fire was burning in multiple directions towards Glenreagh, Nana Glen and Coutts Crossing.
“The Liberation Trail fire has joined the Old Glen Innes Road Fire, Shultz Road Fire, Billys Hill Fire, Twelve Sixty Fire, Black Mountain Fire and Muck Creek Fire,” the RFS website stated.
Mr Bruce said that “all fires and their causes will be investigated in due course”.
“There are a lot of lightning fires in the region,” he said.
However, Mr Bruce said reignition of older fires, due to the severity of the fire conditions, could also be a factor.
“A hot log could roll over and cause a reignition,” he said. “But some causes won’t be able to be pinpointed.
“There are no confirmed causes of the ignition of fires at the moment.”
Mr Bruce said this year’s fire season had presented precedents, for example there have been “fires burn in the same place as those 12 months ago, [propelled] by fuels [regrowth] that are only 12 months old”.
On Monday, the RFS was preparing for Tuesday’s predicated severe (far north coast), extreme (north coast) and catastrophic fire ratings along the NSW coast and inland, with a catastrophic forecast for Greater Sydney and Greater Hunter, including the Blue Mountains and Central Coast areas.
“At the moment there are over 100 fire-fighters on the ground across the Clarence Valley,” Mr Bruce said.
“There are strike teams from all over the state and interstate from Victoria and Tasmania … and incident management personnel, too.”
He said that crews were “not just from the RFS”.
“We’ve got NSW Fire and Rescue, Forest Corporation and National Parks and Wildlife Service fire-fighters working in and around these areas to protect their own assets and also the community’s,” he said.
He said he had never seen such high Forest Fire Danger Index numbers across the state.
“We in uncharted territory at the moment,” he said.