FAA Aircraft Dispatcher Practice Exam

What characterizes an occluded front?

1. Involves only one air mass

2. Made up of two warm air masses

3. Composed of three air masses: two cold and one warm

4. Indicates a severe weather front

The correct answer is: Composed of three air masses: two cold and one warm

An occluded front is characterized by the interaction of three distinct air masses: typically, two cold air masses and one warm air mass. This situation occurs when a cold front catches up to a warm front, forcing the warm air mass upwards between the cold air masses. The result is a front that combines elements from both types of fronts, hence the complexity of its structure. The presence of an occluded front is significant in weather patterns because it represents a transitional stage in the life cycle of a weather system. It often leads to various weather phenomena, including precipitation, changes in wind direction, and temperature drops, as the warm air is forced aloft, allowing the cooler air to take its place. This dynamic nature of occluded fronts can lead to significant weather events, but it is this characteristic composition of air masses that primarily defines an occluded front. Other options do not accurately describe occluded fronts. For instance, referring to only one air mass misses the complexity and interactions involved. A front made up of two warm air masses mischaracterizes the temperature contrasts essential to front formation. Lastly, while occluded fronts can be associated with severe weather, this is not a definitive characteristic, as not every instance of an occluded front leads to severe conditions.