An occluded front is a weather pattern. It brings cold weather and leaves cold weather. It happens when a cold front overtakes a slow-moving warm front. The cold front is heavier than the warm front and will push it up. The warm front slides over the cold one.^[1] Cloud and rain form along the occluded front until temperatures become equal as the cold and warm air mix.^[2] Some occluded fronts make tropical cyclogenesis.