FAA Aircraft Dispatcher Practice Exam

What does the absence of wind indicate during fog formation?

1. Fog is less likely to form

2. Fog is guaranteed to form

3. Fog formation is favored

4. Wind always dissipates fog

The correct answer is: Fog formation is favored

The absence of wind during fog formation is significant because it often creates the ideal conditions for fog to develop. When there is little to no wind, the air remains relatively stable, allowing for the cooling of the air to the dew point. This cooling process, combined with increased humidity, leads to condensation and the formation of fog. In windy conditions, air movement can disrupt the temperature gradients necessary for fog to form. Wind can also mix the air, preventing the cool, moist air from settling in a way that encourages fog development. Without this mixing, stagnant conditions prevail, making it more likely that the dew point will be reached, thereby facilitating fog formation. Thus, the absence of wind does indeed favor the conditions under which fog can develop, as it helps maintain the necessary temperature and humidity balance conducive to fog.