On Monday, residents of the Darling Downs and Granite Belt regions, which includes Toowoomba and Warwick, will face the highest fire threat rating.

The neighbouring Maranoa and Warrego regions will also be subject to a rating of extreme, the second-highest under the new national rating system.

Queensland Fire and Emergency Services chief superintendent Tony Johnstone said the catastrophic rating meant fires could be “uncontrollable”.

“Resources (emergency personnel) may actually have to stand back and let things burn until it actually gets to a safe place,“ Mr Johnstone told the ABC.

Subject to the recently introduced national bushfire rating system, the rating also means lives could be lost and comes as conditions on the ground worsen.

The Bureau of Meteorology warned last week large swathes of Australia should brace for a dry and warm spring after one of the hottest ever winters.

Bureau of Meteorology climate services manager Dr Karl Braganza said unusually warm days are likely for almost all areas during spring this year.

“The forecast shows most areas have a high chance of below average rainfall, and many areas have an increased chance of an unusually dry spring,” he said.

“The recent wildfires in Canada and Hawaii underscore risks, in particular the catastrophic potential of fires near urban areas during periods of low rainfall.“

BOM has yet to officially declare an El Nino weather event, but said on Thursday that it was likely to form during the Australian springtime this year.

Conditions are expected to ease on Tuesday in Queensland, with the danger rating for the two affected regions knocked down to extreme and high respectively.

Inland Queensland, which will face a high threat level from the Maranoa to the Gulf Country on Monday, will also see conditions subside to high or moderate threat levels.

For Mr Johnstone and fire crews already on the ground in southeastern Queensland, the change will come as limited relief as seasonal fire fighting efforts already get underway.

“This year, we‘re seeing more grass fires escalate quickly, and as we saw yesterday at a number of jobs we had to respond quickly to keep those grass fires small,” he told the ABC.

“People on the land are probably aware of the hot conditions and are prepared for it. But it‘s the bystanders and the other people that travelling through that need to be aware.

“If you‘re coming up to smoke, don’t slow down, that could be a firefighter or someone working on the side of the road and we’d hate for you to be involved in a catastrophic event.”

In NSW, conditions will be moderate with high threat levels forecast for northern parts of the state on Tuesday, while Western Australia’s southern interior will face an extreme threat level.

Originally published as Residents on alert after ‘catastrophic’ fire warning for south QLD