occluded front

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The front formed when a cold front occludes a warm front.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun meteorology An occluded front occurs when a cold front overtakes a warm front at the surface and a temperature contrast exists between the advancing and retreating cold air masses.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (meteorology) a composite front when colder air surrounds a mass of warm air and forces it aloft