The type of front where a warm air mass is cut off from the ground by cool air beneath it is called a warm occlusion.

Here's a breakdown:

* Occlusion: This refers to a complex weather system where a cold front catches up to a warm front.

* Warm Occlusion: In this specific type, the cold front is colder than the air ahead of the warm front, forcing the warm air aloft. This leaves the warm air mass isolated above the ground, with cooler air both ahead and behind it.

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