Final answer:
Occluded fronts occur when a faster-moving cold front overtakes a slower-moving warm front, leading to changes in weather conditions.
Step-by-step explanation:
Occluded fronts occur when a faster-moving cold front overtakes a slower-moving warm front, leading to the development of occluded fronts. As the cold front catches up with the warm front, it lifts the warm air above it. This lifting action creates a zone of low pressure, which can cause the formation of clouds and precipitation. The occlusion process can be visualized using a simple diagram:
In this diagram, the blue line represents a cold front, the red line represents a warm front, and the purple line represents the occluded front that forms when the two fronts merge. The occluded front is characterized by a mixture of warm and cold air, and it often brings about changes in weather conditions.