What does torching refer to in fire behavior?

Torching refers to the specific phenomenon where the foliage of a single tree is ignited from the bottom up, causing the flames to travel through the tree's branches and crown. This can occur when intense surface flames from a nearby fire, combined with environmental conditions such as high temperatures and dry vegetation, lead to the ignition of the lower branches and leaves.

As the fire moves upward, it can create a significant impact on fire behavior by increasing the intensity and potentially leading to crown fires if multiple trees begin to torch in proximity. Understanding torching is crucial for fire behavior analysis and for predicting how a fire might spread, especially in forested areas.