The cold front catches up to the westward portion of the warm front, forming an occluded front. Eventually, the cyclone stacks with the upper level disturbance, becoming isolated within the cold sector, and begins to weaken as it becomes far removed from the original temperature discontinuity along the cold and warm fronts. At this point, it becomes a cold-core low.
The advancing cold front collides with the western portion of the warm front, resulting in an occluded front formation. The cyclone eventually merges with the upper-level disturbance, becoming isolated within the cold sector, and begins to weaken as it moves away from the original temperature boundary between the cold and warm fronts. At this point, it transforms into a low-pressure system with a cold core.