Wildland Firefighting Practice Exam

What can be expected from fires burning under an inversion when conditions change?

1. They will become more volatile

2. They may remain dormant

3. They will grow larger

4. They may completely extinguish

The correct answer is: They may remain dormant

When fires are burning under an inversion, the stability of the atmosphere plays a critical role in their behavior. An inversion layer traps cooler air at lower levels and prevents it from mixing with warmer air above, creating stable conditions. This stability often leads to reduced fire activity, as it inhibits the vertical spread of heat and smoke. If conditions remain unchanged, the fire may continue burning at a low intensity, leading to a scenario where it may appear dormant. Under these circumstances, while the fire is not completely extinguished, it does not exhibit vigorous growth or extreme activity. However, if conditions change—such as an increase in temperature or wind—this could disrupt that stability, potentially leading to a resurgence in fire activity. Therefore, the expectation that fires may remain dormant under inversion conditions reflects a key understanding of how atmospheric phenomena influence fire behavior.