Wildland Firefighting Practice Exam

What causes fire behavior to become more erratic in certain environmental conditions?

1. Stable weather

2. Inversions

3. Increased fuel moisture

4. Lower elevation airflow

The correct answer is: Lower elevation airflow

Fire behavior can become more erratic in certain environmental conditions primarily due to factors that influence how fire spreads and interacts with the surrounding environment. Lower elevation airflow, particularly when associated with dry, downslope winds like those that can occur with certain geographic formations, can lead to unpredictable fire behavior. When airflow is driven by topographical features, it may create swirling winds that can change direction quickly, causing flames to shift unpredictably and making it difficult for firefighters to assess the fire's behavior. This kind of erratic fire behavior can also be intensified by variations in temperature and humidity at lower elevations, further complicating the fire's growth patterns and spread. In contrast, stable weather conditions, inversions, and increased fuel moisture generally contribute to more predictable fire behavior. For instance, stable weather promotes consistent conditions that help firefighters anticipate fire movement, while high fuel moisture can inhibit fire spread by making it harder for flames to ignite and sustain themselves.