Wildland Firefighting Practice Exam

What is the term for moisture streamers beneath cumulus clouds that indicate possible adverse winds?

1. Virga

2. Condensation

3. Precipitation

4. Humidity

The correct answer is: Virga

The term for moisture streamers beneath cumulus clouds that indicate possible adverse winds is virga. Virga occurs when rain falls from the cloud but evaporates before it reaches the ground, creating streaks of moisture that can visually signal changes in wind patterns aloft. This phenomenon can be crucial for wildland firefighters, as the presence of virga could suggest turbulent winds that may affect fire behavior and safety. The other terms do not accurately describe this specific meteorological phenomenon. Condensation refers to the process of water vapor turning into liquid, but it does not directly relate to visible moisture beneath clouds. Precipitation is a general term for any form of water, such as rain or snow, that falls to the earth but doesn't specifically address the evaporative process seen in virga. Humidity describes the amount of moisture in the air but does not involve the visual indicators present in virga.