FAA Ground School Practice Test

What atmospheric feature is typically marked by a significant change in wind direction?

1. A low pressure system

2. A high pressure ridge

3. A front

4. An inversion layer

The correct answer is: A front

A front is a boundary between two different air masses, typically characterized by a significant change in temperature, humidity, and wind direction. When a front passes through an area, it often leads to noticeable shifts in meteorological conditions, including a sudden change in wind direction. The movement of the front itself can be associated with the lifting of warm air over cooler air or the mixing of air masses at different temperatures, which can have dramatic effects on local weather patterns. In contrast, low pressure systems and high pressure ridges are broader weather systems that may involve changes in wind direction, but they can do so over a more gradual area rather than providing the sharp boundary characteristic of a front. An inversion layer typically refers to a situation where warmer air traps cooler air at the surface, and while this can affect wind patterns, it is not specifically marked by a change in direction like a front. Therefore, the defining characteristic of a front is its ability to create a pronounced change in wind direction, making it the best answer in this context.