Occluded front pushes the warm sector of a low pressure system aloft, and overrides the colder air that was in front of the warm sector. this often creates areas of complex weather.

The correct answer is:

Warm occluded front pushes the warm sector of a low pressure system aloft, and overrides the colder air that was in front of the warm sector. This often creates areas of complex weather.

Explanation:

Occlusion occurs when rapidly moving cold front combined with slower moving warm front and form occluded front.

Occluded front is the weather front (i.e. the boundary which separates masses of air having different densities). It is formed when the cyclonic circulation is developed in the atmosphere.

There are two types of occluded fronts:

Cold occluded front is the occluded front which is formed when colder air pushes the warm sector of a low pressure system aloft. Cold front causes heavy rain, hail, lightening, thunder.

Warm occluded front is the occluded front which is formed when warm air pushes and over rides the cold sector of a low pressure system aloft. Warm front causes storms and makes the weather complex.