In meteorology, when a cold one has a close encounter with a warm one & takes it over, it's called an occluded one
[DOC] [TLE] Occluded Front: when a cold front overtakes a warm front [PAR] A developing cyclone typically has a preceding warm front (the leading edge of a 
warm moist air mass) and a faster moving cold front (the leading edge of a... [DOC] [TLE] Weather Fronts - OK-First - Mesonet [PAR] If the wedge is moving into an area of warmer air, the front is called a cold front.