A warm air mass that is cut off from the ground is said to be an occluded front. Occluded fronts generally occur in areas of low pressure and create stormy conditions and changes in temperature and wind speed.
There are two different kinds of occluded fronts. The first is cold occlusion, which is similar to a cold front. This happens when the air behind an occluded front is colder than the air in front of it. The colder, heavier air mass lifts the warmer air above itself.
The other type of occluded front is warm occlusion, which acts like a warm front. In this type, the air behind the occluded front is warmer than the air in front of it.