106 Surface Observation Fundamentals Practice Exam

Cirrus clouds are thin, wispy clouds that usually form at high altitudes and are composed of ice crystals. Their presence often indicates that a change in the weather is on the way, specifically signaling the approach of a weather front. This is because cirrus clouds often develop ahead of warm fronts and indicate that moisture is rising, which can lead to the development of other cloud types and precipitation.

When cirrus clouds appear, it usually serves as a precursor to changes in the atmosphere, such as shifts in air masses that can bring rain or storms. Thus, cirrus clouds typically suggest that weather conditions are likely to change soon, which aligns with the correct answer that they indicate approaching changes in the weather.