What is 'catastrophic' fire danger?
Parts of Victoria have been warned to prepare for catastrophic fire danger today as a burst of hot, windy and stormy weather spreads across the state. So, what does catastrophic fire danger mean and what should Victorians do to stay safe in these conditions?
Image: Forecast fire danger ratings in southeastern Australia on Tuesday, February 13, 2024.
The Australian Fire Danger Rating System (AFDRS) is a four-tiered national rating system that describes the potential level of danger on a given day, should a fire start.
Australia’s daily fire danger ratings are calculated using observations about the current state of the bushfire fuel, combined with forecasts from weather and fire behaviour models.
There are four levels in the AFDRS, with each rating also carrying a simple message to encourage appropriate action to protect lives:
- Moderate: Plan and prepare.
- High: Prepare to act.
- Extreme: Take action now to protect your life and property.
- Catastrophic: For your survival, leave bush fire risk areas.
On days with moderate fire danger, people are advised to stay up to date and be ready to act if there is a fire. These are days with a Fire Behaviour Index (FBI) value between 12 and 23.
High fire danger means there is a heightened risk and people should be alert for fires in their area and decide what they will do if a fire starts. If a fire does start, life and property may be at risk. The safest option is to avoid bushfire risk areas on these days. These are days with a Fire Behaviour Index (FBI) value between 24 and 49.
When there is extreme fire danger, conditions are dangerous, and people should reconsider travel through bushfire risk areas. It is important to check bushfire plans and ensure that properties are fire ready. If a fire starts, people should take immediate action. If any people or property are not prepared to the highest level under these conditions, you should go to a safer location well before the fire impacts. These are days with a Fire Behaviour Index (FBI) value between 50 and 99.
The highest level of fire danger in Australia is catastrophic fire danger. These are the most dangerous conditions for a fire. Life may depend on the decisions made, even before there is a fire. People should go to a safer location early in the morning or the night before if possible. Homes cannot withstand fires in these conditions and if a fire starts, people may not be able to leave, and help may not be available. These are days with a Fire Behaviour Index (FBI) value of 100 or higher.
While fire danger ratings give useful information about the potential level of danger, they don’t guarantee that a fire will start, nor do they give any information about current fires.
Image: Australian fire danger ratings and corresponding FBI values. Source: AFAC
Anyone located in an area with elevated fire danger should closely monitor information from their state or territory’s fire emergency agency: