Wildfire Knowledge Graph · Fire Behaviour
A fire front spreading against the prevailing wind or downslope, commonly slower than the head fire in the same fuels.
In plain language
A fire front spreading against the prevailing wind or downslope, commonly slower than the head fire in the same fuels.
Why it matters
Backing Fire is useful because it separates one specific part of wildfire behaviour, exposure, operations or evidence from nearby concepts that can otherwise be mixed together.
What is a backing fire?
A backing fire is the portion of a fire that normally spreads more slowly and at lower intensity while moving into the wind and/or downslope. NWCG also uses a related spread definition for fire moving, or deliberately ignited to move, against the wind or downslope.
Backing fire vs head fire
A head fire spreads with the wind and is generally associated with faster forward spread. A backing fire progresses in the opposite relationship to the driving wind or slope and typically has a lower rate of spread under otherwise similar conditions.
Why the term can be confusing
“Backing fire” can describe observed fire behavior and can also appear in prescribed-fire or firing-operation terminology. Context matters: an incident report describing the rear or backing portion of a wildfire is not necessarily describing a deliberate ignition operation.
Official reference: NWCG — backing fire.
Related: Head, Flank and Rear of a Wildfire.