•Occlusion: the warm air is cut off from the surface by the meeting of two fronts.
•Usually, a fast-moving cold front catches a slow-moving warm front.
•A cold-type
occlusion: eastern
half of the
continent where a cold front associated with cP air meets a warm front with mP air ahead.
•A warm-type
occlusion: western edges of continents where the cold front, associated with mP air, invades an area in which colder cP air is entrenched.