What weather change occurs when flying across a front?

When flying across a front, a notable weather change that occurs is a shift in wind direction. Fronts are boundaries between different air masses, and as an aircraft flies through a front, it typically encounters a change in the characteristics of the air. Specifically, the wind direction usually shifts as the aircraft moves from one air mass into another.

For example, in a cold front, the wind may come from the northwest before the front and shift to the southwest after passing through. This directional change in wind is significantly impacted by the differing temperatures and pressures associated with the two air masses involved in the front.

While temperature change, humidity change, and cloud cover increase can also occur when crossing a front, they are not as directly indicative of the transition that happens at the front itself. The alteration in wind direction is particularly critical for flight operations and navigation, making it an essential aspect when pilots anticipate or react to flying through frontal systems.